Brazilian Pipeline Community

The Brazilian Pipeline Community

Brazil oil & gas oil & gas
EPRASHEED
signature series
Brazil
Supplement to

Pipeline Technology Centre
www.eprasheed.com

Norway oil & gas

The Brazilian Pipeline
Contents
Liquid PiPeLines and TerminaLs
Marcelino Guedes – Director, Petrobras Transporte

João Carlos de Luca a free sTanding hyBrid riser for deePwaTer
President, IBP Francisco E. Roveri – Petrobras R&D – CENPES

The Brazilian Institute of Petroleum and ProjeCTs and ConsTruCTion of new oiL and gas
Gas (IBP) with the support of its Pipe- PiPeLines in BraziL
line Commission has been working to Breno de Souza e Silva & Ney Passos – Petrobras Engineering
develop Brazil’s pipeline industry by
helping companies in this sector oper- PiPeLine inTegriTy Program
ate in a profitable, efficient, ethical and Paulo de Tarso Arruda Correia – Petrobras Transporte
socially responsible way.
In this context, the Commission pro- BraziL’s PiPeLine TeChnoLogy CenTer – CTduT
motes the exchange of ideas and ex- Raimar Van den Bylaardt – CTDUT
perience amongst professionals in this
industry and is active in the areas of soCiaL and environmenTaL resPonsiBiLiTy
norms standardization, promoting in- Ana Paula Grether de Mello Carvalho
ternational trade missions and in the
organization of courses and events. suBmarine PiPeLine insPeCTion
Among the latter we can highlight the Claudio Camerini & Miguel Freitas
Rio Pipeline Conference and Exhibi-
tion as a world class forum to debate PiPeLine and shiPPing TeChnoLogy
the major issues facing the international suPPorTs PeTroBras
pipeline industry. César José Moraes Del Vecchio, Petrobras R&D – CENPES

The BraziLian gas TransPorTaTion sysTem
Marcelo Renno – Director, Petrobras Transporte

rouTe seLeCTion and sTruCTuraL design for The
goLfinho gas exPorT PiPeLine
Marcelo José Barbosa Teixeira, Claudio Roberto Mansur Barros,
Mônica de Castro Genaio, Carlos Terencio Pires Bomfimsilva, Vivianne
Cardoso Pessoa Guedes, Janaina de Figueiredo Loureiro
Wajid Rasheed
CEO & Founder, EPRasheed
editors Publisher
Andre Raposo, Daniel Brossi, Breno Souza, Ney Wajid Rasheed
Brazil has the potential to export world wajid.rasheed@eprasheed.com
Passos, Francisco Roveri, Pedro Barusco, Paulo
class technology and services. For this Correia, Ana Paula Carvalho, Marcelo Renno,
to happen, an export culture needs Marcelo Teixeira, Claudio Barros, Monica Genaio,
Carlos Pires, Vivianne Guedes, Janaina Loureiro.
managing editor
to be cultivated. Part of this culture is Majid Rasheed
a single source of technical material Contact: andreraposo@petrobras.com.br majid.rasheed@eprasheed.com

that focuses on Brazil while including

Brazil oil & Brazil oil & gas
gas
the wider international observers. This
supplement ‘The Brazilian Pipeline EPRASHEED
signature series
Community’ is a channel for companies,
both oil and service to share expertise www.eprasheed.com
with the wider export market.
Norway oil & gas

Community viewpoints

Sergio Gabrielli – President, Petrobras Ildo Sauer – Director, Petrobras Paulo Roberto Costa – Director
Gas and Power Area Petrobras Bunkering

Over the next few years we will be witnessing Petrobras is changing from an oil company Strategically important to supply energy to
the third boom in pipeline activity in Brazil. into an integrated energy Company. Natural Brazil, Petrobras’ pipeline network operates
Building new oil, natural gas and bio-fuel gas is playing a fundamental role in the in strict accordance with Health, Safety and
pipelines will be our challenge. organization as its share of the Brazilian Environmental standards.
energy matrix increases.
We will look to new technologies to ensure As a result, the investments allocated for the Through advanced monitoring technology,
environmental and operational safety with natural gas chain in the 2007-2011 period we can guarantee the safe transportation of
social responsibility. amount to US$22.1 billion, a 71 percent raw materials and products at competitive
increase over the previous budget. costs.

Sergio Machado – President, Eloi Fernandez y Fernandez – Director Renato Duque – Director
Petrobras Transporte General, ONIP (The National Petroleum Petrobras Services
Industry Organisation)

Transpetro has prepared itself to meet increas- Since 1999, ONIP has been working to Raising professional skills and implementing
ing demand generated by self-sufficiency and increase local content in oil and gas projects new pipeline construction and monitoring
the growth of Brazil’s oil and gas sector. in Brazil. For the pipeline sector, we have technologies are our challenges.
New ships, terminals and pipelines will recently released a publication, entitled
guarantee logistical supply in a country that ‘Who is Who in the Pipeline Industry in Our goal is to expand the pipeline network in
has the dimensions of a continent. Acquired Brazil’. Our main objective here, is to present a safe and efficient manner while minimising
over the last 30 years, our experience of local capacity to investors, as we are very environmental impact.
Ethanol logistics places our company as the optimistic about the future of the Brazilian
industry benchmark and market leader. pipeline industry.


Liquid Pipelines
and Terminals
Marcelino Guedes, Director - Petrobras Transporte

Transpetro is present in the whole age tanks for oil and oil products, buoy mooring systems and five
of Brazil, through the operation of in addition to 80 globes for LPG, mono-buoys, with the objective of
44 terminals and a pipeline net- Transpetro has the installed capac- unloading in locations where the
work of around 7,000 km of oil ity to store approximately 10 mil- coastal conditions do not allow the
pipelines, operating from the north lion m³ and transport around 53 mooring of ships.
of the country in the Amazon re- million m³/month of oil and oil
gion – pipelines ORSOL I and II products, in addition to handling operational safety
and terminals in Coari, Manaus around 4,600 shipping operations
and Belém – to the extreme south per year. Complementing the in- Transpetro maintains the consistent
– Rio Grande Terminal. With an frastructure of these terminals, policy of improving the safety of its
infrastructure of around 500 stor- Transpetro owns two multiple operations. In the Pipeline Integrity

Liquid Pipelines and Terminals – guedes

Program (PIP) alone, US$ 630 mil- ard of safety for the operational voluntary certifications for the In-
lion have been invested – with the control of the pipeline network tegrated Management of Quality,
result being a reduction in the vol- throughout Brazil. From there, the Health, Safety and the Environ-
ume of leaks to the order of 93%. technicians accompany remotely ment (QSMS) – ISO 9001 (qual-
PIP, which is destined to ensure per- and in real time the operations in ity), ISO 14001 (environment)
fect functioning of the installations the pipelines. NOCC is equipped and OHSAS 18001 (international
and reliability of operations, has with computers and the leading norm for occupational safety) – be-
been continuously revised and has edge technology. Supported by ing evaluated by international certi-
gained new monitoring tools. the Supervisory Control and Data fying agencies.
Acquisition (SCADA) software,
The implementation of the Terminal the operators receive immediate Within the projects aimed at in-
Integrity Program (TIP) began in detailed information about what creasing operational safety pipe-
2005. This will establish a series of is happening in the pipelines and lines, is the Program for the Greater
technical projects with the objective monitor the levels of flow, pressure, São Paulo Outflow Logistics Refor-
of achieving excellence in the safety temperature and density of the oil mulation. The project, with invest-
and integrity of the installations and and the gas. At the least sign of any ment of around US$1 billion, sub-
infrastructure of the units. The in- abnormality, the system allows for stitutes the existing pipeline network
tegrity programs for pipelines (PIP) telecommand interventions such as installed in the metropolitan region
and terminals (PIT), which include the switching on or off of pumps, of São Paulo, with an external net-
stabilization of the slopes, renova- or the opening or closing of valves work. The objectives are to provide
tion of piers and storage tanks are in any stretch. the network with the capacity to
being enhanced by the training of handle growing volumes of oil, oil-
the workforce. Pipelines and terminals, just like derivatives and other products. And
all of the Transpetro installations, to reduce the safety risks associ-
The National Operational Control comply with norms that go beyond ated with heavy urbanisation along
Center (NOCC) ensures the stand- the regulatory demands, having the pipeline rights-of-way in Greater
São Paulo.
graphic shows Petrobras emergency Bases
In addition to all the care taken
with operational safety, Transpetro
maintains an infrastructure to re-
spond to emergencies that includes
a Center for Emergency Pipeline
Repairs (CREDUTO) in Guarul-
hos – São Paulo, and 49 Emer-
gency Response Centers (CREs and
CDAs) spread around the country,
with equipment and teams trained
for a rapid response to any accident
with a possible impact on the envi-
ronment.

new Projects
The increase in the price of oil and
the growth in demand for fuels with
less impact on global warming have
led to the search for biofuels. In
Brazil, the Transpetro Program for
CREs – Transpetro Management – 34 Ethanol Logistics gained impetus
CDAs – Petrobras Management – 9 due to the Brazilian experience
Advanced CDA Bases – 6 with alcohol technology, and the
prediction that by 2014 demand for


ethanol will reach 25 million m³ in west of São Paulo, Mato Grosso The highlight among the new projects
the domestic market and 5.5 million and Goiás to Paulínia and take for oil pipelines is the study for the
m³ abroad. Transpetro is preparing the same quantity of diesel oil and implantation of a pipeline of around
to increase its capacity of fuel ethanol gasoline from Paulínia back to 1,400 km between the REPAR Re-
outflow from the present 1.2 million these regions. The investment is finery in Araucária and the cities of
m³ per year to 9.4 million m³ per US$ 236 million. Londrina, Campo Grande and Cui-
year in 2015, with investments in abá, with the objective of reducing
exclusive pipelines and tankage in • Ethanol pipeline Guararema-São the logistics cost of transporting oil
the Southeast, the South and the Sebastião: capacity for four mil- products to the central-west region,
Northeast of Brazil amounting to lion m³ per year. The investment meeting the growing demand gener-
US$532 million. The principal is still being evaluated. ated by the expansion of agribusiness
investments are as follows: in that area.
• Construction of three more tanks
• Ethanol pipeline Paulínia-Guarar- at the Maceió Terminal, increas- The increasing demand for natural
ema: exclusive pipeline for ethanol ing the capacity from 400,000 gas in Brazil, predicted to grow by
with the capacity for eight million m³ per year to 700,000 m³ per 14% per year to 2010, accompanied
m³ per year with an investment of year. The investment is US$ 4 by the need for diversifying supply,
US$ 154 million. million. has led to the acceleration of projects
for water-based terminals with the
• Ethanol pipeline Uberaba-Ribei- • Paranaguá Terminal: adaptation capacity to receive, vaporize and dis-
rão Preto-Paulínia: capacity to of an existing tank, construc- patch natural gas. For this purpose,
transport four million m³ per year- tion of two additional tanks and projects are being developed for the
with an investment of US$100 a platform for tanker trucks with implantation of terminals capable
million. the enlargement of the wagon of receiving ships carrying Lique-
platform to increase the capac- fied Natural Gas (LNG) initially in
• Tietê-Paraná Waterway: capacity from 400,000 m³ per year to Ilha D’Água – Rio de Janeiro, in the
ity for transporting four million 700,000 m³ per year. The invest- southeast of Brazil and in PECEM
m³ of ethanol per year from the ment is US$ 4 million. – Ceará, in the Northeast.

graphic shows schematic of Pipelines

new riser development–
a free standing hybrid
riser for deepwater
Francisco E. Roveri – Petrobras Research & Development Center – CENPES/Subsea Technology Group

introduction The hybrid riser concept, which
combines rigid (steel) pipes with
Petrobras is considering the single- flexible pipes has been utilized by the
line FSHR (Free Standing Hybrid offshore industry since the 80’s. The
Riser) design as an option for large Riser Tower first installed by Placid
diameter export risers in deepwater. Oil at Gulf of Mexico in Green Can-
This large bore specification com- yon 29 was refurbished and re-uti-
bined with the deepwater environ- lized by Enserch. More recently, the
ment put this application outside concept underwent some changes
the present feasibility range of solu- for application at Girassol field in
tions such as flexible pipes and steel Angola, where three towers were
catenary risers (SCRs). Both these installed by Total. The Riser Towers
solutions present high top tension at Girassol field are positioned with
loads for installation and operation. an offset with regard to the FPU,
The lateral buckling failure mode in whereas at GC29 the vertical por- lized by Placid. After a long period, it
flexible pipes and the fatigue damage tion of the riser was installed by the was only in the year 2000 that this al-
in the touch down zone (TDZ) of semi-submersible FPU and was lo- ternative was considered for concep-
SCRs are further design limitations cated underneath the derrick. tual studies at Albacora Leste field, in
currently only solved by the use of 1290 meters water depth, for the P50
heavier pipes which further compro- Five water and gas injection turret moored FPSO.
mise hangoff loads in a negative de- monobore FSHRs (10 to 12-inch)
sign spiral. have recently been installed in West Two alternatives were considered for
Africa offshore Angola, at Kizomba comparison: a Steel Lazy Wave Riser
The FSHR system has a reduced field in about 1200 meters water (SLWR) and a concept combining
dynamic response, as a result of depth. The design of these risers rigid and flexible pipes. In 2003
significant motion decoupling be- has some key differences to one of Petrobras contracted the concep-
tween the Floating Production Unit the concepts presented in this pa- tual study development of the Riser
(FPU) and the vertical portion of per, each of which offers different Tower solution for the starboard side
the FSHR system and its vessel in- design and operational advantages. 8-inch production lines of the P52
terface loads are small when com- Riser towers are being developed for semi-submersible platform. Two
pared with SCRs or flexible pipe so- installation in the Greater Plutonio towers were considered, each com-
lutions. Therefore it is an attractive and Rosa fields in Angola. prising seven production lines and
alternative solution for this kind of one spare line. In 2003 Petrobras
application. There are further cost Petrobras has been studying the hy- also contracted the feasibility stud-
savings associated with this concept brid riser concept for some years. In ies of an export oil FSHR to be con-
due to the added advantage of hav- 1989 a feasibility study was developed nected to a semi-submersible plat-
ing the riser in place prior to the for Marlim field, Campos Basin, for a form in water depths of 1250 and
installation of the FPU. configuration similar to the one uti- 1800 meters.


system description The FSHR runs from the hangoff gooseneck is the flexible jumper. The
slot at FPU to the Pipeline End Ter- flexible jumper connects the free-
The FSHR design may have a number mination (PLET) located near the standing section of the riser system
of variants. Two configurations are riser base. The lower end of the verti- to the vessel, and includes bend stiff-
presented hereinafter, the main dif- cal part interfaces with a stress joint. eners to ensure that the range of ro-
ference being the interface between Below the stress joint there is the tations experienced at the end con-
the Buoyancy Can (BC), the vertical offtake spool, which connects to the nections do not damage the jumper
pipe and the flexible jumper. foundation by means of a hydraulic due to low radius of curvature. The
connector. A rigid base jumper con- flexible jumper has enough compli-
Configuration a nects the mandrels located at the ance such that the vessel motions
offtake spool and PLET, providing and offsets are substantially decou-
The configuration described below is the link between the FSHR and the pled from the vertical portion of the
considered for an oil export riser to pipeline. The foundation pile will be FSHR system, and consequently the
be installed from a MODU (Mobile drilled and grouted and may typical- wave-induced dynamic response of
Offshore Drilling Unit), due to the ly be offset from the FPU by more the free standing riser is low.
availability of such vessels already than 200 meters.
under contract at Campos Basin. Configuration B
The riser pipe passes through an in-
The FSHR consists of a single near ner 36-inch OD stem within the BC, The position of the gooseneck in
vertical steel pipe connected to a and is guided within the stem by cen- relation to the BC is the main dif-
foundation system at the mud line tralizers. Where the riser pipe is sub- ference between the West African
region. The standard riser joints are ject to high bending loads such as the and Configuration A designs. In the
18-inch OD x 5/8-inch wall thick- keel ball centralizer on the BC, taper earlier design, the gooseneck is posi-
ness X65 material. The riser is ten- joints are used to reduce the stress in tioned below the BC and the verti-
sioned by means of a BC, which is the riser pipe. The BC is secured to cal riser is tensioned by the can via a
mechanically connected to the top the riser pipe at the top of the BC by flexible linkage or chain.
of the vertical pipe. The vertical pipe means of a bolted connection.
is always kept in tension in order to This arrangement simplifies the inter-
maintain the FSHR stable for all the At the top of the free-standing riser face between the BC and vertical riser,
load cases. The BC is 36.5 m long x is the gooseneck assembly. This as- and allows pre-assembly of the flex-
5.5 m diameter. It has 16 compart- sembly consists primarily of the ible jumper to the gooseneck before
ments and the maximum upthrust is gooseneck and an ROV actuated hy- deployment of the vertical riser. How-
about 570 Te. The BC is located 175 draulic connector which allows the ever, in the event of flexible jumper
meters below the sea level, therefore gooseneck and flexible jumper to be replacement or repair, an elaborate
beyond the zone of influence of wave installed separately from the vertical jumper disconnection system needs
and high current. section of the riser. Attached to the to be employed below the BC.

fig. 1 shows Configuration a. fig. 2 presents Configuration B.

riser development – roveri

Positioning the gooseneck at the top deployment through the BC. Other suited to deepwater applications.
of the BC allows for independent in- differences are the foundation type The design is relatively unaffected
stallation of vertical riser and flexible (suction piles x drilled and grouted by severe environmental loading or
jumper. A flexible pipe installation pile) and bottom interface (flexjoint non-heave optimized host vessels
vessel can install the flexible jumper x tapered stress joint). when compared to SCRs and flex-
when required. This minimizes the ible risers. The robustness allows the
risk of damage to the flexible jumper Configuration B presents the goose- riser to be conservatively analyzed,
during installation as the procedure neck positioned below the BC. The and allowances for design changes
is similar to that of a shallow water vertical riser is tensioned by the BC and uncertainties to be included up-
flexible riser with the first end at via a flexible linkage or chain and front in the design process, thus giv-
the top of the BC. This design also the hub is in offset with regard to ing greater confidence in the overall
facilitates and minimizes the time the vertical section of the FSHR. system design.
for flexible jumper retrieval in case This allows the flexible jumper to be
of damage, in service, to any of its installed in a similar way as Configu- For engineering, procurement and
components such as the stiffener, ration A, therefore overcoming some construction (EPC) contractors not
end-fittings or pipe outer sheath. disadvantages of this configuration having a suitable vessel, or unable to
and previous designs. mobilize their vessels to install the
On the other hand, it is necessary to FSHR, the ability to use a MODU
have a continual vertical riser string Conclusions as the installation vessel could prove
right through the centre of the BC to be an attractive alternative.
to provide a connection hub for the In the FSHR design concept, the
flexible jumper at the top. This ar- location of the BC below high cur- It can be said that the FSHR concept
rangement introduces interfaces be- rent and wave zone, and the use of extends the reach of deepwater riser
tween the riser string and BC which the flexible jumper to significantly feasibility as it avoids the main techni-
have to be carefully analyzed and decouple vessel motions from the cal problems faced by other solutions,
engineered. In addition, installation vertical riser greatly reduce the sys- and arguably, it may be among the
analysis has to be conducted to assess tem dynamic response, resulting few proven riser concepts feasible for
the loads on the riser string during in a robust riser design particularly deepwater large bore applications.

Always
innovating
for the best

Azevedo & Travassos develops innovative solutions to meet the needs of its Oil and Gas clients.
Consequently, it is recognized as one of Brazil’s Foremost Construction Companies with the best know-how in the market.
The result of this investment can be described by a single word: credibility.
In the end, those that have been working for so long, can only do things well.


Projects and Construction
of new oil and gas
Pipelines in Brazil
Breno de Souza e Silva & Ney Passos – Petrobras Engineering

general Considerations lion cubic meters per day, of which ian consumption of oil derivatives
71 million will be produced in do- in 2005 was 1.766 thousand bpd,
In light of ever-growing gas demand mestic fields. with an estimated growth of 3.1%
and the increasing difficulty of meet- p.a in the next five years, reaching
ing such demand through gas im- Additionally, the demand for trans- a expected consumption of 2,117
portation, Petrobras envisaged Bra- portation of crude oil and deriva- thousand bpd in 2011.
zilian self-sufficiency in natural gas tives is also growing. The installation
production and is accelerating the of new refining units and the re- Such is the background to the in-
process of achieving it. Today, the vamping of some existing ones were vestment plan of the oil and gas
consumption of the country is 45.5 required to meet a growing market, pipeline network expansion in the
million cubic meters per day and by which ranges from fuel consump- country, bringing about new jobs
the year 2011, it may reach 121 mil- tion to petrochemicals. The Brazil- as well as new technologies. In or-

souza & Passos

der to meet the demands of the gas aged which will either be rented or gram (PROMINP) developed by
market and make it possible for owned by Petrobras. This will result the federal government.
field production flow, Petrobras is in roughly 30 turbo-compressor sets
investing US$ 4.4 billion in the with installed power varying from The issues related to health, safety
next five years in the enlargement 7.200 HP to 23.800 HP each. and environment cannot be forgot-
of the gas pipeline network. With ten. The works to be implemented
respect to the increase in oil pipe- Petrobras is also investing in the require social responsibility and
lines and terminals, the expected development and improvement of maximum care and respect to the
investment for the next five years is the operating and safety conditions particular characteristics of the re-
US$ 3.0 billion. of terminals and pipelines, many of gions crossed by the pipelines.
which are in urban areas. To this ef-
Pipeline Projects fect, the São Paulo Master Pipeline To provide efficient outflow of large
Plan (PDD-SP), foresees transporta- volumes, pipelines with greater diam-
Regarding projects and construction of oil, derivatives, natural gas eters and higher pressure ratings are
tion of oil and gas pipelines, the and alcohol through a new pipeline required. Increasing steel resistance
actions taken by the Engineering and right-of-way network introduc- means avoiding greater thickness of
department of Petrobras have al- ing optimized operating logistics and pipe. The benefits include saving steel
ready shown practical and visible substituting the existing network, by weight reduction, and therefore,
results. which will interconnect terminals the costs of pipe purchasing, pipe
and distribution companies in the construction and assembly are all re-
In the Northeast region of the state of São Paulo. The purpose of duced.
country we find unmet gas demand, such modifications are the adapta-
which has resulted in increased in- tion of paths and strips of land along At present, the oil and gas pipelines
vestments in the transportation and the pipelines’ route so that they of greatest resistance in Brazil are
distribution infrastructure, mostly blend in better with the surrounding manufactured with pipes of X70
based on thermoelectric plants for communities, as well as preparing degree in conformity with API 5L
power generation. the network to cope with the growth specification, which has reliable con-
of the state of São Paulo. struction and assembly techniques.
The Southeast region already has a On the other hand, Petrobras has
booming transportation and distri- The petrochemical complex of Rio de participated in many attempts to in-
bution network, especially in Rio Janeiro (COMPERJ) will also require novate pipe fabrication technology,
de Janeiro and São Paulo, where gas the construction of new pipelines, in- such as the study of fabrication and
consumption is high. The projects cluding crude oil and petrochemical. application of API 5L X80 pipes,
to expand pipeline network are also the evaluation of new welding pro-
encouraged by the growth of the It is worth noting that Petrobras cesses for highly resistant steels, the
piped gas distribution network in faces considerable challenges with study for application of pipes with
the metropolitan regions as well as regard to the construction of oil helicoidal welding, as well as its par-
the demand related to industry and and gas pipelines. There is an exten- ticipation in the working out of the
thermoelectric plants. sive oil and gas pipeline that needs Brazilian standard for heat bending
to be implemented and operated in by induction.
If we only consider existing oil and a safe and socially responsible way.
gas pipelines we may note that our And time runs short as the number Conclusion
gas pipeline system in Brazil is not of projects increase. To rise to such
wholly integrated. However, the challenges Petrobras is counting on The expansion of Brazil’s oil and gas
unmet demand from the Northeast, technological innovations, which pipeline network is a fundamental
the first production from fields in are under development. Society is necessity in order for the economic
the Espírito Santo and the promis- also called to provide the necessary growth of our country.
ing Southeastern market will be in- resources as qualified manpower
terconnected by the GASENE Gas and a competitive and efficient in- The Engineering Department of
Pipeline. dustry to supply equipment and Petrobras is fully committed to this
material of proven quality. It is goal and is not sparing any efforts in
For these gas pipeline networks, worth mentioning the national oil order to develop the new technology
10 compression stations are envis- and gas industry mobilization pro- required to complete new projects.


Transpetro Pipeline
integrity Program
Paulo de Tarso Arruda Correia, Petrobras Transporte S. A. – Transpetro

introduction This new standard began establishing
routines for inspection, control and
The project is part of the PEGASO mitigation for what were called four
Program – (Operational Safety and main failure modes: Internal Corro-
Excellence in Environmental Man- sion; External Corrosion, Third Party
agement). It started in 2001, with Action; Pipe and Soil interaction.
a large and intense pipeline physi-
cal integrity recovery program, The PID document comprised eight
followed by the adjustment of the chapters covering: Risk Analysis; In-
company’s pipeline grid (more than ternal Corrosion; External Corrosion;
9,650 km of natural gas, oil and oil Third Party Actions; Soil and Pipe
product pipelines) and led to the Interaction (Geotechnical Problems);
new Petrobras Integrity Standard Pigging; Defect and Repair Analyses;
or PID (Padrão de Integridade de Pressure Testing.
Dutos).
All these PID chapters were applied Standard as a permanent practice of
The Program was started after three to each pipeline in the company’s the company.
pipeline accidents in the country; the network in a way that the control
first one in Guanabara Bay with a fuel of the program was carried out per The emergency Phase
oil line (PEII 16”, 13.7 km) in Janu- pipeline.
ary/2000, resulting in a leakage of This was applied to a priority list of
1300 m3; the second in a crude pipe- Program structure 96 pipelines (6,084.9 km) selected
line in July/2000 (OSPAR 30”, 118.5 for strategic and risk reasons. These
km) with 4000 m3, lost and the third The program as a whole, delivered were selected from among the 183
one in a diesel pipeline (OLAPA 12”, a reduction in the leakage volume pipelines (9,650 Km) that would be
94.0 km) with 150 m3 lost in 2001. from 6,000 m3 in 2000, to less considered in the whole program.
A fourth accident with a fuel oil pipe- than 39 m3 in 2003, the leakage
line (OBATI 14”, 50 km) happened has been kept at a very low level In this emergency phase, more
in May/2001 due to external corro- since then. than 245 km of new and different
sion resulting in a leakage of 200 m3 pipelines, representative of the in-
of atmospheric residue, and a fifth in Three phases and five processes were stalled base considering items such
July/2001 in OBATI Clean products identified. These were the ‘Emer- as nominal diameters, material and
14” pipeline due to Third Party Ac- gency Phase’ to rapidly recover the wall thicknesses, were purchased and
tion also resulting in a leakage of 200 physical integrity of a set of priori- used to assist in the repairs that came
m3 of LPG. tised pipelines. This included the as- after an in-line inspection program,
sessment and recovery of integrity as using MFL or ultrasonic pigs.
Transpetro has invested more than well as adjusting the whole pipeline
US$600 million to date, aiming to network to the Petrobras Pipeline A total of 5,480.1 km of pipeline
adjust its pipeline network to the new Standard. Additionally, it included was inspected through intelligent
level of integrity demanded by PID. the introduction of the Pipeline pigs (geometric, high resolution

Transpetro Pipeline integrity Program

Transpetro's Pipeline Network Quantity Lenth After a careful experimental research
Regional Nr. Pipelines Nr. Row KM program, Petrobras developed a self-
NNE 42 15 2596,83
integrity criterion for the assessment
of pipelines with corrosion defects.
SE 60 14 2763,54
The RPA methodology may be used
SPCO 61 27 3260,00
alternatively for ASME B31-G, gen-
SOUTH 20 9 1029,90 erating a reduction of 49% in the
TOTAL 183 65 9650,28 preventive repairs carried out after
in-line inspections.

MFL and ultrasonic) resulting in problems, etc. The headquarter's Petrobras also has a laboratory de-
the repair of 5,200 defects. This re- committee performs the whole voted to the development and tests
sulted in 5,094.3 km of rehabilitat- program coordination, issuing a of smart-pig tools in its Research
ed pipeline. During this phase more monthly report and keeping a spe- Center, CENPES. This laboratory
than 87 new employees were hired cific site on the company home has developed tools of different types
to work in the integrity area and al- page. such as Geometric, MFL, pressure
most US$400.00 million were in- and temperature profiler with an
vested. Transpetro has created a standard, accelerometer and new technology
negotiated with the ILI services pro- for internal corrosion and geometry
This phase started in early 2001 vider companies, for the format of deploying the polygraph principles.
and ended in 2003 (the target was pig inspection reports (magnetic and The following areas have been re-
07/2002 but the repairs continued hard copy) that make the interpre- searched:
until mid 2003). tation easier as well as the data pro-
cessing, using a toll that estimates internal Corrosion (iC)
The adjustment to Petrobras the wall resistance, the defects that
Pipeline standard must be repaired as well as defining In order to control and mitigate the
the next inspection (described be- IC, the project in this area comprised
In this phase all Pipeline standard- low) called Planpig. the following main items:
ization actions were applied to each
pipeline through a variety of differ- Planpig is a novel methodology de- Implantation of infra-structure in-
ent projects and according to a WBS veloped by Transpetro for pipeline cluding:
(Work Breakdown Structure). management in-line inspection pro-
grams. • Petrobras project and installation
The management of the program of corrosion coupon and Electri-
considered a structure composed of This software was developed to cal Resistance Corrosion Probes
five Committees, one in headquar- determine the best (risk and cost (ERCP) in the 6o/c position (bot-
ters and one in each of Transpetro’s based) time interval between in-line tom line of the pipes).
regions. inspections and the preventive re-
pairs to be carried out following a • Development of new corrosion
Typically, the Regional Com- pipeline inspection. The innovative inhibitor additives, injection sta-
mittees brought together repre- feature of this methodology is that it tions and updating the existing
sentatives of the following areas: takes into account the expected fail- units with automation.
Health, Safety and the Environ- ure cost, the cost of inspection and
ment; Commercial; Marine Ter- the cost of repair to determine the Implementation of a set of routine
minals; Oil Pipelines; Gas Pipe- optimal failure risk at the moment services considering:
lines; Engineering. of inspection as well as the ILI tool
accuracies and internal and external Periodical cleaning of the pipelines
The Regional Committee promot- corrosion rates. with scraper pigs: IC management
ed periodic coordination meetings service routine to collect samples
where the different agents had the By applying this methodology a re- from the debris dragged by the scrap-
opportunity to exchange ideas, duction of 46% in the expenditure er pigs, NACE test of samples from
update each other regarding the on in-line pipeline inspection was product batches pumped through
progress in their activities, discuss obtained. the pipelines.


external Corrosion (eC) ic map, and takes into account the re- than 5 years, and that need to oper-
sults of special and periodic surveys. ate again; Pipelines that have been
In EC the project encompassed the fol- operating at one pressure level that
lowing items: External coating survey Among the most common problems need to operate at a pressure 25%
using PCM, ACVG, DCVG and CIPS are: River crossing erosion causing higher, although lower or equal to
for mapping and sizing the disconti- the pipeline exposition leading seg- the one allowed by the last test.
nuities in the external coating as well ments to be without support; Soil Pipelines that have been operating
as being a way to provide the mapping movement in mountain slopes (hill- for more than 25 years without a
of the pipelines at the ROW (Right Of sides); Soil erosion with the exposi- new valid pressure test; Pipelines
Way) without the mapping tool. tion of the pipeline by heavy rain; out of operation, even in periods
The collapse of the soil by under- lower than 5 years that have not had
The CPs supervisory system ground water movement; The ac- an appropriate hibernating process.
tions of strong waves or strong tides These criteria were applied to the
A great advance in the program was in the sea to beach transition. pipeline network, and as a result,
the application of the supervisory 101 pipelines were tested.
system for the CPS. risk analyses
r&d in Pipeline, Pipeline
This system called STR (Sistema de The Risk Analyses chapter in the Technological Center,
Telesupervisão Remota) is based on Petrobras Pipeline Standard is one Cooperative Projects
a set of sensors installed in the rec- of the most important in the whole
tifiers or the interference current document. Petrobras has in its Research and De-
drainage equipment like voltmeters velopment Center (CENPES) a lab-
(AC and DC), current meters (DC It is the qualitative analyses that con- oratory devoted to the development
output current), soil to pipe voltme- sider the consequence potential and and testing of smart pigs tools. This
ter with a permanent semi-cell and a the failure probability of the four fail- laboratory has developed Geometric
switch in the entrance door to detect ure modes considered in the PID. tools, MFL and pressure/tempera-
invaders in the rectifier shelter. ture profiler.
The pipelines are divided into seg-
The external Coating inspection ments according to the geographical Recently, Transpetro took part to-
and environmental factors. The con- gether with other companies in the
The surveys using the methods al- sequence potential takes into account: foundation of an independent and
ready described, have proved to be the environmental classification; class private Pipeline Technological Cen-
very efficient in pinpointing the ex- location; operational conditions like ter (CTDUT – Centro Tecnológico
ternal coating failures and a lot of re- product, flow rate and pressure (only de Dutos).
pairs have been carried out in points for natural gas pipelines).
where the coating was severely de- Two pipeline loops are being con-
graded or did not exist any more. Up All 183 pipelines in the network had structed, the larger one with 12”,
to May 2006, a total of 7,626km of their risk evaluated by this process. 2.4 km for liquids and the smaller
the pipeline network, or 79% of total one for gas with 14”, 130m.
network had been inspected and a to- Pressure Test
tal of 3,499km were rehabilitated. Conclusion
In the PID standard the pressure test
geotechnical or soil/Pipeline is either mandatory or recommend- Transpetro is fully committed to
interaction ed, based on the following cases: the improvement of the integrity
of its pipeline network. It does this
The PID created the requirement to Mandatory Cases: New pipelines; Af- through a sound pipeline integrity
develop a geographic plan produced ter pipeline repair; Pipelines that need program which aims to achieve
from aerial photography that allows to operate under pressure higher than higher safety levels and more eco-
the identification as well the clas- that allowed by the last valid hydro- nomical operations. The total in-
sification and sizing on a three level test; Pipelines in sensitive areas. vestment of more than US$600
scale (severe, medium and moderate), million covering a broad range of
of all geological problems along the Recommended Cases: Pipelines projects as described herein, con-
pipeline. This plan is called a themat- that remain out of use for more firms this commitment.

sponsored by Tgs

Progress in the development of a predictive
model for finding locations of significant high-
ph stress Corrosion Cracking in gas pipelines.
Transportadora de Gas del Sur S.A. is of cracking has been a priority for titatively, the physical and chemical
the leading gas transportation com- TGS since its beginnings. agents involved in this process.
pany in Argentina. Not only does
TGS operate the longest and oldest Currently, the Company is working on This fact, along with the low resist-
pipeline system in Latin America, two technical fronts to detect and pre- ance of the soils where SCC has
(7,972 Km of pipeline, 579.090 HP vent SCC effects. On the one hand, been found, and the proximity to
compression power, 74 MMm3/d of we are running in-line inspection tools rectifier facilities, has allowed TGS
contracted capacity), it also renders (TFI & EMAT), to this date with un- to present new and unknown vari-
integral processing services (1 mil- certain results, and on the other hand, ables to be considered in the search
lion tons/year of Ethane, LPG and TGS is developing a susceptibility for significant SCC.
gasoline), treatment (12 million m3/ model. To such purposes, the team of
d) and compression (36,800 HP) of specialists in charge of the task has de- With the implementation of a reli-
natural gas in gas fields. veloped its own soil model. able susceptibility model we will be
able to predict, with a high degree of
These services comprise construc- observable results certainty, the sites where significant
tion, operation, maintenance and high pH SCC is likely to be found
financial structuring. The thorough research carried out without the need to interrupt the
by TGS' team of specialists is based service for its study. It will also al-
In the past, the Company overcame on geo-morphological surveys of low us to repair the cracks before a
the challenge of achieving interna- each area, the interpretation of high devastating rupture occurs.
tional standards in controlling exter- resolution satellite images, and field
nal pipeline corrosion. Today, consist- works which consist of observation Leading the way in the investigation
ent with its policy of safety, accident pits, which allow the physical and of this phenomenon, TGS keeps in-
prevention and its constant pursuit morphological characterization of vesting, developing and researching
of quality, TGS has set up – within the soil and the extraction of samples – together with its team of specialists
its Pipeline Integrity Team – a group for subsequent laboratory chemical – the best methodologies to mitigate
of specialists and experts devoted to analysis. and prevent SCC, thus successfully
the research and development of a rendering excellence and quality in
predictive model for finding cracks Based on field research and by means its service.
produced by high-pH stress corro- of laboratory tests we were able to ob-
sion cracking (SCC) in pipelines, tain artificial cracking similar to the
thus preventing service interruptions one found in our system, thus being
arising from this phenomenon. able to assess, qualitatively and quan- www.tgs.com.ar

Causes and effects View of cracks produced by stress corrosion cracking through pipeline wall thickness.

SCC can be observed in pipes as a
cracking in the external surfaces of
pipelines (generally, lengthwise) gener-
ated by the combined action of corro-
sion and tension attributed to: pressure
variations, high temperatures, pipeline
coating conditions, soil components
and cathodic protection potentials.

The search for efficient methodolo-
gies and practices to detect this kind


CTduT
The ‘Pipeline Technology Center – CTduT’ is a laboratory equipped with field facili-
ties for testing/certifying products, full scale simulations and the research and
development of new technologies in pipeline activities. CTduT is also designed to
offer specialized pipeline training. CTduT contains a pull test unit for Pig testing, an
integrity Laboratory for burst tests, a gas flow Loop, and a separate liquid loop
for tests under real operating conditions.
Raimar Van den Bylaardt – CTDUT

CTDUT is a Technology Center In the search to develop leading edge the multiplication of activities
created by Transpetro, Petrobras technology for pipeline transport, planned for the business and aca-
and PUC-Rio (The Catholic Uni- CTDUT is emphasized as the fun- demic sectors.
versity) with support from the Fed- damental link in the implantation of
eral Government, resources from a Brazilian network of competence Nowadays, CTDUT has 19 as-
the Oil and Gas Sectorial Fund in pipelines, bringing together pipe- sociates: Azevedo & Travassos,
(CTPETRO), and linked to the line operators, companies, universi- Chemtech, GDK, IMC Saste, In-
Ministry of Science and Technology ties, research centers, civil society tec do Brasil Ltda., Intech Engen-
through FINEP. It is a non-profit and government agencies. haria, Pipeway, TDW, TSA Tubos
association open to all companies Soldados Atlântico, TWI, Univer-
working in pipeline operation, con- The structure built to comprise the sidade Federal Fluminense (UFF),
struction, engineering, R&D, train- technological center is open to all Conduto, Brazilian Petroleum &
ing, environment, services, and also those companies and institutions Gas Institute (IBP), Petrobras,
government sectors and regulating that wish to strengthen the develop- PUC-Rio, Transpetro, IEC and
agencies. ment of this project, thus enabling Aselco.

CTduT

CTDUT headquarters is located in applied in pipelines in operation. was applied, the MFL tool does not
the city of Duque de Caxias, state of In these cases it is named internal damage the coating and nor is its ac-
Rio de Janeiro, close to a Terminal coating in-situ. This kind of appli- curacy affected by the coating.
from Transpetro that supplies the cation is more complicated due to
center facilities with oil, diesel and the difficulty of surface preparation Submarine pipelines are quite often
natural gas. and the application of the coating more difficult to inspect than on-shore
itself, that is commonly applied by pipelines. The access difficulties and
The use of the pull test unit began in using pigs. In Brazil, the first in- the inadequate design for inspection
1999 to verify the capability of de- situ coating application was done with pig are the most common reason
tection, the precision of sizing and in 2002[1]. The average coating for naming these pipelines as “unpig-
the absence of false calls. Since then, thickness is about 300 µm. As with gable”. Other factors also contribute
several tests of pig performance have any pioneering work, many tests for the difficulty of inspection of those
been done with the goal of testing were performed to assure the qual- submarine pipeline specially the large
new technologies, tools for appli- ity of this new technology. Part of thickness and relatively small diam-
cations, innovative prototypes and those tests were performed in CT- eters – commonly these pipelines have
adaptations for special case inspec- DUT pull test unit to check if the nominal diameters under 20 inches.
tions. This pull test unit consists of MFL tool would damage the coat-
several pipeline segments installed ing after a certain amount of runs To make inspection feasible of a 12
in a metallic structure containing and verify the influence of the coat- inch nominal diameter, 3/4 inch thick
shelves and an electrically powered ing in detecting and sizing external submarine pipeline, a specimen was
winch that moves a wire inside all of defects. assembled in the CTDUT pull test
the section of the shelves. unit in order to evaluate the magne-
To realize this test a 28m length tization capability of a MFL pig. Sev-
some Tests realized in CTduT specimen of pipeline segment was eral internal and external defects were
built and assembled into the shelves introduced into the specimen. Some
The internal coating of pipeline of the pull test unit. In this segment internal defects had their geometry
has become more important in in- flanged spools were introduced aligned with the longitudinal direc-
ternal corrosion prevention. More which had the same coating as the tion of the pipe to simulate the typi-
frequently pipelines are built and pipeline. After the specimen was as- cal morphology of internal corrosion
assembled with internal coating for sembled, an internal inspection was defects.
reducing friction and assure a better realised by a MFL.
quality of the product. Apart from The tool applied in this experiment
application coating before pipeline From results of the test, it was con- was a magnetic pig. This pig was
assembly, sometimes the coating is cluded that when the in-situ coating specially designed to maximize the

12” diameter - 2.4km in length with in-
14” diameter loop - 120 meters in tegral supply tanks, pumps, automation
length. and state-of-the-art controls.


magnetism to preserve the method These projects will be used for re- • Training and qualification of op-
sensitivity even in those adverse con- search, test and training, with a par- erators and technicians.
ditions of large thickness and small ticipation of research centers and
diameter. universities of Brazil, as well as with
the operators, service companies and
In the first trial the pig did not pres- equipment manufacturers. references
ent sufficient magnetism, that led to
a non-detection of some defects. In The following needs had been iden- (1) Lachtermacher, M., Souza Filho,
the second version the magnetism tified to develop these projects: B, Andrade, L.; “Emprego de reves-
reached values as specified and all timento para proteção interna em
defects were detect. • Research and development of new dutos”; 6ª Conferência sobre Tecno-
equipment, tools, inspection sys- logia de Equipamentos – 2002; IBP;
some Projects in development tems and pipeline protection. Salvador-BA, Brasil.

Nowadays, CTDUT is working on • Flow tests for simulation software (2) Franzoi, A. Et All; “Inspeção de
the construction of 3 loops: approval. Oleodutos com Paredes Espessas
com Ferramenta MFL – A experiên-
• 14” diameter and 100m in length • Tests and certification of equip- cia da Bacia de Campos”; Rio Pipe-
for liquid transport; ment and control system, protec- line Conference 2005; IBP; Rio de
tion, corrosion control, inspection Janeiro – RJ, Brasil.
• 12” diameter and 2,4km in length and maintenance of pipeline.
for liquid transport; For more information, contact
• Certification of process and pro- the Pipeline Technology Center –
• 16” diameter and 2,4km in length cedures of operation, inspection CTDUT – www.ctdut.org.br.
for gas transport. and maintenance.

social and environmental
responsibility
Pipeline right-of-way and family
based agro-business
Ana Paula Grether de Mello Carvalho

In 2003, Petrobras joined one of ness performance should include low income neighborhoods of Nova
the most important corporate so- economic, social and environmen- Iguaçu and Duque de Caxias, in the
cial responsibility projects in the tal responsibility. state of Rio de Janeiro, Brazil.
world – the UN Global Compact.
Since then Petrobras has defini- ‘The Agro-ecological Family Farm- The focus regions of the project are
tively adopted social and environ- ing Project along Pipelines Right-of- the low income communities of Ge-
mental responsibility concerns as Way’ is a joint Petrobras Transporte rard Danom and Jardim Geneciano
part of its core values. Respecting and ‘Instituto Terra de Preserva- in Nova Iguaçu Municipality, close
human and labor rights, protect- ção Ambiental’ (NGO) and ‘Onda to the borders of Tingua Nature Re-
ing the environment and fighting Verde’ (NGO). Launched in De- serve, and the low income commu-
corruption are all major challeng- cember 2005, it has created veg- nity of Amapa in Duque de Caxias
es that face Society. Petrobras is a etable gardens, an agro-industry and Municipality. All of them are crossed
company that believes that its busi- an ‘Online Learning Centre’ in the by the stretch of pipeline (ROW).


Since most of the dwellers of those The novel aspects of the project are an environment of discussion and
communities live below the poverty the promotion of social inclusion analysis of community problems,
line, it is crucial to implement so- and guaranteeing economic, envi- so that it is possible for different
cial projects that promote job and ronmental and social sustainabil- groups to express different opinions
income generation and encour- ity through two main points. First, on such problems.
age social organization. Moreover, adopting participative/ongoing diag-
Petrobras Transporte considers ag- nosis and planning methodologies, By using visual diagrams for collect-
riculture a form of fostering closer creating an evaluating and planning ing information, such as a spoken
relations with the population in the culture by the methodology of Par- map, flowchart, Venn diagrams and
neighborhoods on the edge of its ticipative Rural Diagnosis (PRD). other tools, the local population and
underground pipelines, and of pro- Second, the objective of placing the the project technical assistants are able
tecting its equipment and the pop- organic productions in the market, to build diagrams and discuss results.
ulation against possible accidents throughout local and regional pro- The outcome of the work is a collec-
caused by third party actions. duction chains and arrangements, tive understanding of how reality is to
provides ways to add value to the be transformed. Such methodology
‘The Agro-ecological Family local farm production, including engages the participants deeply in the
Farming Project along Pipelines the families in certified production project and at the same time empow-
Right-of-Way’ consists of a five- chains. ers the local population so that they
module agro ecological produc- become aware of this social space and
tion unit, covering a production The methodology of Participa- how to transform it.
area of 96,000 m² (100 vegetable tive Rural Diagnosis (PRD) aims
gardens of 960 m²), directly serv- to perform critical and integrated Supporting ‘The Agro-ecological Fam-
ing 100 farming households. The analysis of the rural reality involv- ily Farming Project along Pipelines
project not only contributes to- ing the population and the project Right-of-Way’, Petrobras shows its
ward maintaining the pipelines, in technical assistants. The PRD is not committed to extending the quality
compliance with the safety and en- a conventional diagnostic process of its positive performance to social
vironmental standards adopted by in which specialists collect infor- action at the communities where it
the company but also assists low- mation from the farmers then later operates. This is the way that Petro-
income households by providing unilaterally plan the activities of the bras System proposes to fight against
technical support and financing to project. The purpose of PRD is to poverty in Brazil: Development with
find better jobs and increase levels encourage dialogue between farm- Citizenship.
income generation. ers and specialists in order to set up

submarine Pipeline
inspection
feeler snake Pig: a simple way to detect
and size internal Corrosion
Claudio Camerini & Miguel Freitas

Submarine pipelines are traditionally Other equally relevant factors make Another characteristic of submarine
inspected with the same technologies the inspection difficult, like subma- pipelines inspections is that almost al-
used for onshore pipelines. A good rine pipeline wall thickness, which ways those pipelines are accessed from
example of this is an inspection using limits significantly the use of magnetic outside, with visual inspection using
instrumented pigs, which is usually instrumented pigs – MFL – magnetic ROVs – Remotely Operated Vehicles.
based on the same parameters, pro- flux leakage. As oil production heads Those vehicles are already periodically
cedures, and tools used in onshore for deeper and deeper waters, pipe- used to inspect Petrobras’ submarine
inspections. In those circumstances, lines become thicker for structural pipelines, to identify external dam-
some problems, of course, are ex- reasons, and that implies loss of MFL ages, measure cathodic protection
pected to happen. Onshore pipelines pig measurement capacity. Those pigs electrochemical potential, identify
are usually easy to access, and that present reduced sensitivity as from 15 spans, etc. That external visual access
enables excavating for field verifica- mm-thick wall with a practical limit of is, compared to onshore pipelines, the
tions and correlations, thus allowing 20 mm. The problem becomes more greatest differential regarding subma-
inspection quality measurement. The serious in diameters smaller than 14- rine pipelines inspection.
same is not true for submarine pipe- inch diameter pipelines, which present
lines, in which a correlation of instru- large thickness and small internal vol- Another aspect that favors subma-
mented pig indicated results implies ume, making magnetization very dif- rine pipelines is that the main cause
very high costs or, in some cases, is ficult, as the space available to place of deterioration is internal corro-
not technologically possible. magnetizers is not much. With cur- sion, which occurs in the presence of
rent technology, there are not enough produced water. External corrosion
During the 1980’s and 1990’s, on- compact and high-power magnetizers is easily prevented with cathodic
shore pipelines received strong in- to be used on large thicknesses in such protection, while damage caused
vestments in Brazil in order to be small spaces. by collisions or anchor action are,
able to receive instrumented pig in- mostly, identified through ROV
spections, such as: removing small visual inspection. It is considered,
radius bends; installing launchers therefore, that the main objective
and receivers; unifying diameters; of inspecting oil and gas production
and removing obstacles. Some sub- submarine pipelines is to detect and
marine pipelines received the same quantify internal corrosion and, in a
treatment, but those adaptations lesser degree, external defects related
were not extended to the whole net- to diverse actions.
work, once the investments required
were, at least, of a higher level. It’s An alternative technology available
very common, therefore, to find sub- Figure 1 - Feeler Pig measur- in the market to inspect pipelines
marine pipelines with various diam- ing method. Corrosion effects subject to internal corrosion is the
eters and small radius bends, among (pits) are measured according use of pigs with ultrasound tech-
other obstacles that prevent the use to angle variation of sticks. nology. Depending on its mechani-
of conventional instrumented pigs. cal design, the ultrasonic pig may


eter variation, in addition to short
and long pipelines with a wide
range of flow speed. In July, 2006,
an inspection was performed using
a feeler snake pig, which is a fully
innovative design using the above
mentioned method. Figure 3 shows
the new concept of instrumented
pig, in which sensors (sticks) are
mounted on a flexible base. That
Figure 2 - (a) Feeler pig for 22”, with 250 sensors (sticks); b) Feeler pig for
tool enabled a multi-size inspection,
16”, with 180 sensors (sticks).
with small radius bends, a kind of
inspection that tools commercially
available cannot provide. As a re-
tolerate variations in diameter, and inspection of a submarine pipeline in sult, 7.6 kilometers of a submarine
does not present inconveniences Campos Basin, with excellent results, pipeline were recovered.
for measuring large thicknesses. A thus confirming the tool’s potential
severe limitation to that method is in the field. Figure 2 shows the pig For consolidating the feeler pig
the need for a homogeneous liq- assembled and ready to use. Results technology and the feeler snake pig
uid, with good acoustic properties, delivered by the pig’s 250 sensors concept, Petrobras is changing its
to serve as coupler. That limitation (sticks) were compared with a pre- submarine pipeline inspection sys-
makes it more difficult to inspect gas vious inspection performed with a tematic, prioritizing that technology
pipelines, requiring introduction of commercial ultrasound pig. The new for internal corrosion control. The
a diesel batch, but with strong op- tool delivered results that were identi- use of other pigs, like MFL and ul-
erational impact. Also, the fluid is cal to those of the ultrasonic pig, con- tra-sound, will still occur whenever
not homogeneous in production firming, therefore, under real condi- there is a suspicion of external corro-
pipelines with “live” oil (oil + gas + tions, the technical viability of the sion. With the new system, Petrobras
water), making ultrasonic inspection new internal corrosion detection and intends to inspect the vast majority
practically impossible. quantification method. of its submarine pipelines, practically
eliminating the expression “non-pig-
In this context, Petrobras, together Based on the aforementioned re- gable line” from its offshore produc-
with PUC-RIO, developed a sub- sults, several inspections using that tion fields. Therefore, Petrobras pio-
marine pipelines inspection method system are being scheduled for neers the inspection of production
to detect and size up loss of wall 2006 to 2008, and include oil and pipelines that were usually excluded
thickness associated to internal cor- gas pipelines with or without diam- of routine pigging inspections.
rosion. A special pig was designed
to bear large variations in diameter,
have no practical limit of thickness
to be inspected, and be able to navi-
gate through curves and geometric
accessories with small bend radii.
The tool was named a ‘Feeler Pig’, as
it consists of several feeler-type sen-
sors that measure internal corrosion,
as illustrated in Figure 1.

At first, the special pig was devel-
oped for small diameter production Figure 3 - Feeler Snake Pig – a new concept of instrumented pig, where
pipelines, however, because of its sensors are mounted on a flexible base to allow inspection of usually non-
potential shown in field tests, a first piggable pipelines. (a) – batteries and electronics modules; (b) 12 sensor
prototype was constructed for large modules, totaling 144 sensors distributed across pipeline’s perimeter; (c)
diameter pipelines, in this case, 22 general view of equipment during pre-launch check.
inches. That prototype carried out an

Pipeline and shipping
Technology supports
Petrobras
César José Moraes Del Vecchio

R&D activities in Petrobras on these • Ship design, construction and in- than in onshore pipelines, made it
subjects are coordinated by means tegrity management. difficult to detect and quantify the
of a Technological Program – PRO- internal corrosion of the lines. Petro-
TRAN, with specific projects led Most of the projects are developed bras R&D changed this scenario
by specialty groups from Petrobras in house, with part of the scope con- with the development of an in-line
R&D – CENPES as well as by par- tracted to Brazilian science and tech- inspection tool.
ticipating in joint industry programs nology institutions, however some
and projects. are contracted abroad. The innovation, known as the 'Pig Es-
pinho' is able to identify and measure
PROTRAN, dedicated to pipeline We consider part of this portfolio a loss of pipeline wall thickness caused
technology since 1997, in its early group of eighteen projects we sup- by internal corrosion. It is based on a
stages has put substantial effort in port as members of Pipeline Research series of very sensitive feeler rod and
qualifying and helping to assimilate Council International (PRCI). Also miniature electronics. It can handle
the most up-to-date solutions avail- part of the portfolio are eight projects large diameter variations and has mul-
able for operational challenges. Re- targeted at increasing the capabilities tiple uses as it can inspect thicknesses
cent work on pipelines has been part of Brazilian Universities and Institutes of any size and can negotiate tight
of the international industry effort to support a set of 26 ships that will bends. It is also able to by-pass geo-
to improve safety, minimize risk and be built for Petrobras Transporte SA, metrical accessories with narrow bend
reduce capital and operational costs. run directly by Rio de Janeiro Federal radius and can tolerate high tempera-
University, São Paulo State University ture and high-pressure environments.
The present portfolio of PROTRAN and The São Paulo Institute of Tech-
includes projects in eight subjects: nology. Figure 1 shows sensing elements on
a 22” diameter ILI tool used in an
• Corrosion Management; The following paragraphs discuss offshore pipeline. A recent run has
some highlights of projects that have
• Leak Detection Systems; just finished or are under way.

• Pipeline Rehabilitation; multi-size iLi Tool
• In Line Inspection (ILI); The existing equipment, known as
Conventional Instrumented Pigs,
• Pipeline Operation and Automa- used in inspections of onshore pipe-
tion; lines was not ideally suited for use in
sub sea oil and gas production pipe-
• Risk management; lines. Frequent diameter variations,
large wall thicknesses, sharp-angled
• Pipeline Design, materials and bends, and the most varied geomet- Figure 1 - Crown of sensing
construction technology; rical configurations, which are far elements in 22” Pig Espinho.
more prevalent in sub sea pipelines


made it possible to inspect an off-
shore line which has a flexible riser.

Corrosion management in
wet gas Pipelines
Typical strategies to mitigate CO2
corrosion to acceptable levels are:
continuous corrosion inhibition,
batch corrosion inhibition, gas de-
hydration, pH control and corro-
sion-resistant alloys (CRA). In the
Cangoá-Peroá field, offshore Espíri-
to Santo-Brazil, there is no facility
available for liquid/gas separation
and treatment on the topside of the Figure 2 - Artistic view of the pipes and pig launcher for the batch treat-
jacket. All production (gas, conden- ment.
sate and produced water) from Peroá
is transported for processing to one
separation and one TEG dehydra- Under these conditions, a continu-
tion facility onshore. On the plat- ously applied corrosion inhibitor is
form, there is a chemical injection not expected to wet the top of the
system, in order to prevent hydrate line. As the 18” gas export pipeline
formation and inhibit corrosion, in- is heavily oversized, it creates a risk
cluding a dedicated pig launcher for of severe corrosion damage due to
batch treatment. No sand produc- potentially ineffective corrosion
tion is expected and the CO2 content control by inhibitor continuous
is 1.25% and 3.06% for Peroá and injection. Combined batch inhibi-
Cangoá respectively. After a number tion is required for protecting the
of simulations and studies Petrobras top.
chose a carbon steel pipeline with a
corrosion allowance of 6 mm and To enhance the batch treatment,
corrosion inhibitor treatment as a the design team developed an in-
suitable materials/corrosion control novative method for this opera-
approach. tion. For that reason, the platform
design considered two pig launch-
One of the concerns for the 18” ers. One vertical pig launcher will
main pipeline is under-deposit cor- be used to run up to seven pigs for
rosion and proper inhibitor trans- the normal operation with an ini-
portation. Under-deposit wall loss tial frequency expected every two
can be very fast even in generally days. The second pig launcher is
low-corrosion medium. Frequent horizontal and will be used for the
launching of scraper pigs would batch operations. As the platform
therefore be needed to ensure clea- is small and crowded, a creative
nout of any solids in the pipeline design configuration was devised
and cup-discs to enhance inhibitor to allow for the installation of the
transportation. Since the predomi- two pig launchers. Figures 2 and 3
nant flow pattern is stratified wavy, show the batch system.
CO2 corrosion rates will be differ-
ent at the bottom of the line (BOL) The pipeline has a dynamic side
and at the top of the line (TOL) stream corrosion monitoring sys- Figure 3 - Artistic view of the
and there are also implications for tem and has just been commis- Peroá platform.
corrosion inhibition application. sioned.

Pipeline and shipping Technology to support Petrobras group

The influence of Topographic A variety of studies on mass wast- our ability to predict landslide sus-
scale in mass wasting ing susceptibility modeling applied ceptibility, the simulations were car-
susceptibility modeling to a pipeline in steep hill slopes of ried out in scales 1:1.000, 1:10.000
the Serra do Mar, close to the city and 1:50.000.
The purpose of mass wasting sus- of Rio de Janeiro, where mainly
ceptibility assessment using a Geo- creeping process are occurring, were The Serra do Mar is a mountain
graphic Information System is to performed. In these numerical ex- range nearby the Southeastern Bra-
assign, in a regional scale, places periments both deterministic (e.g., zilian coast in the states of Rio de
were these events are more probable SHALSTAB – Shallow Landslide Janeiro, São Paulo, Espírito Santo
to take place. The main purpose of Stability Model and TRIGRS – Tran- and Paraná with hill top eleva-
mass wasting susceptibility maps is sient Rainfall Infiltration Grid-Based tions varying from 300 to 2.000
to provide information about the Regional Slope Stability Analysis) and meters. The study area is located
probability of mass wasting occur- empirical models (e.g., SMORPH – in a steep hill slope near the coast
ring. The way in which the digital Slope Morphology Model) were used, in the state of Rio de Janeiro, just
elevation model (DEM) is obtained, as well as a modification of this mod- West of Rio de Janeiro city. An im-
by interpolation or by mesh, has an el in order to detect areas affected by portant pipeline goes through these
enormous influence in determining creep processes. Besides, a model W-E oriented hill slopes, which are
the main topographic parameters based on soil and rock properties mainly composed by Precambrian
of this surface, like the contributing mapped in the field (IPT Model) was metamorphic rocks as gneisses and
area, the flow direction, the slope also tested. In order to characterize migmatites, locally known as Rio
and the hill slope curvature. the influence of topographic scale in Negro Complex.

Figure 4 - The creeping area (red lines) with inclinometers assigned by their labels and showing that the process is occur-
ring in high contributing areas.


The Brazilian gas
Transportation
system
Marcelo Renno, Director – Petrobras Transporte

introduction gas Pipeline network
Natural gas is the world’s fastest- Natural Gas in Brazil
growing primary energy source, be-
ing more environmentally attractive Natural gas usage in Brazil started
as it burns efficiently; it is expected in the 1960´s with the development
to be the fuel of choice in many re- and production of reserves in Bahia
gions. As a result of this, the natural state, in the Northeast of the coun-
gas share of the total world energy try. For this reason the first gas pipe-
matrix will grow from 24 percent in line, called GASEB, was constructed
2003 to 26 percent in 2030 mea- linking the State of Bahia to the State
sured in BTUs. of Sergipe, as shown in fig.1.

In Brazil alone, the consumption of Natural gas exploration continued Pernambuco states with gas produced
natural gas will be growing at 12% to at a low level in the 1970’s until the in the State of Rio Grande do Norte.
15% per year on average, led mainly worldwide oil crises motivated efforts
by vehicular natural gas (VNG) and in exploration and production. Due In the 1990’s production from the
by the industrial market. to these efforts, results started to be Merluza Field began in the Santos
achieved with the discovery of re- Basin, supplying natural gas to the
Petrobras, the state controlled serves in the Espírito Santo and Rio Refineries of Presidente Bernardes
Brazilian energy company, is the de Janeiro states (Campos Basin). and Capuava (GASAN) and con-
principal player in the Brazilian This fact, associated with industry’s necting the State of São Paulo to the
natural gas industry. Its goal for fuel demand, led to the construction natural gas supply system.
2011 is to market an average of of gas pipelines throughout those
120 million cubic meters of natu- states. At that time, the gas pipelines To complete the gas pipeline net-
ral gas per day, well above the cur- called GASVIT, GASVOL and GAS- work in the southeast area of Brazil,
rent total of nearly 46 million cu- PAL were concluded (see description the gas pipeline called GASBEL en-
bic meters per day. in table 1). The latter links the states tered in operation in 1996, allow-
of Rio de Janeiro and São Paulo. ing the natural gas produced in the
To meet this impressive growth in Campos Basin to be supplied to the
natural gas demand, the gas trans- The 1980’s saw the start of natural gas State of Minas Gerais.
portation network will need to be transportation and distribution to the
expanded significantly, with a view northeast area of the country. The gas Towards the end of the 1990’s, two
to connecting the different regions pipeline called “Nordestão” entered new gas pipelines of great impor-
of the country. into operation supplying Paraíba and tance were constructed: GASFOR

The Brazilian gas Transportation system

and GASALP, expanding the natural bras was in charge of the design and system despite being located geo-
gas supply network in the Northeast project implementation. graphically in the Southeast Region;
region of Brazil.
After the construction, TBG (Trans- Apart from the Brazilian part of the
At that time the domestic market was portadora Brasileira Gasoduto Bolivia-Brazil Pipeline, the table be-
supplied only by the domestic gas Bolívia-Brasil S.A.) in Brazil – where low shows the current network in
production. This situation changed in Petrobras is the main partner – and Brazil.
2000, with the conclusion of the Bo- GTB (Gas TransBoliviano) in Boliv-
livia-Brazil gas pipeline (GASBOL), ia became the owners and operators The existing natural gas pipeline
which started the process of natural of the pipeline in their respective network is fully operated by Trans-
gas importation from other countries. countries. petro (Petrobras Transporte S.A) and
TBG, which operates the Brazilian
The Bolivia-Brazil Pipeline The Bolivia-Brazil pipeline includes part of GASBOL.
(GASBOL) twelve compression stations, seven
operational measurement stations Transpetro is the Petrobras System
The Bolivia-Brazil pipeline was the for pig launcher/receiver facilities lo- logistics company, and is responsible
outcome of many years of negotia- cated along the pipeline and thirty for operating areas such as the trans-
tion between the Governments of eight pressure measurement and re- portation and storage of crude oil,
the two countries but it was not until duction stations to supply the vari- oil products, biofuels, petrochemi-
the 1990s that it became part of the ous gas distributors. cals and gas through pipelines, ter-
Brazilian strategy for securing energy minals and ships owned by the com-
supplies. The resulting agreements The Gas Pipeline Network in pany and third parties.
and contracts allowed the construc-
3
Operation
tion of a 30 million m /d gas pipe- Transpetro’s gas pipeline network
line connecting Bolivian reserves to At present, there are three indepen- transportation capacity is increased
the Southernmost part of Brazil and dent gas systems in operation that by compression stations located
also to the pipeline network supplied are not interconnected, due the con- at strategic points. There are ten
by the Campos Basin. tinental dimensions of Brazil: (i) the compression stations in operation,
Southern-Southeastern System (S- distributed in the Northeast and
The pipeline takes gas from the Rio SE), (ii) the Northeastern System Southeast regions of Brazil.
Grande area in Bolivia and ulti- (NE) and (iii) the Espírito Santo
mately supplies it 3,150 km away in state system, which has not yet had All of Transpetro´s operations are
Canoas (Rio Grande do Sul state in its pipelines connected to the S-SE controlled from the National Op-
Brazil). The pipeline crosses the Bra-
zilian states of Mato Grosso do Sul,
São Paulo, Paraná, Santa Catarina
and Rio Grande do Sul; and con- Table 1 - Brazil Gas Pipelines.
nects with the existing gas transpor-
tation facilities in Sao Paulo state.
The pipeline has a diameter ranging
from 32 to 16 inches. It is designed
to reach a gas outflow of 30 million
cubic meters per day when operating
at full capacity.

The GASBOL implementation used
the most advanced technology in
terms of construction techniques,
remote operational systems, line
pipe material specification and in-
spection and testing methodology.
It is important to highlight that the
Engineering Department of Petro-


erational Control Center (NOCC) Petrobras will speed up its development Conclusion
that monitors Transpetro’s network projects in the Santos (São Paulo state),
of oil and gas pipelines with the ex- Espírito Santo and Campos (Rio de Ja- The increasing share of natural gas
ception of supply lines belonging to neiro state) Basins, significantly increas- in the Brazilian energy matrix is
third parties and ship loading and ing the domestic natural gas supply. To the result of higher investments
unloading lines at port terminals. transport this additional input volume, throughout the supply chain. This
The NOCC’s basic concept was de- the Petrobras Business Plan foresees has enabled the development of the
veloped entirely by Transpetro engi- the enhancement of the Southeastern natural gas industry in Brazil.
neers. The NOCC is located in the region’s gas pipeline network. Expan-
Transpetro headquarters in down- sion work will also be undertaken in As a result, Petrobras registered an
town Rio de Janeiro. the Rio-Belo Horizonte Gas Pipeline increase of 13% in the demand of
(Gasbel), in the Southern section of the natural gas in the first quarter of
The system enables operators to open Bolivia-Brazil Gas Pipeline (Gasbol) – 2006 in relation to the same period
and close the valves controlling the to supply the Southern region with the of the previous year, which confirms
flow of gas, adjust the quality and con- gas produced in the Southeast – and in the forecasts of the Company’s Stra-
tent of the gas, and conduct sales at the the Northeastern network. tegic Plan that forecasts an annual
other end, all at the click of a button. growth rate of 17.7% up to 2011.
In addition to optimizing the plan- With the implantation of the South-
ning and transportation of products, east Network and Gasene projects in The future commitment and chal-
real-time monitoring of the network the next 3 years, Petrobras will com- lenge is to continue transporting the
provides greater operational safety. plete the basic Brazilian national gas entire volume of natural gas with
pipeline grid. high levels of performance, assuring
gas Pipeline network optimum gas network reliability, en-
expansion The figure below shows the current vironmental responsibility and high
and future gas pipeline network in safety standards.
The Petrobras Business Plan has allo- Brazil.
cated US$ 6.5 billion for gas pipeline
network expansion up to 2011, there-
by increasing the existing 5,570 km of
gas pipelines by a further 4,160 km. Figure 1 - Brazil Gas Pipelines.

The projects include construction of
the Urucu-Coari-Manaus gas pipe-
line in the Amazon region and also
new gas pipelines in the Southeast
and Northeast regions of Brazil.

Meanwhile, the Gasene – which
will interconnect Southeastern and
Northeastern Brazil – will be con-
cluded by 2008. This gas pipeline
will be formed by sections ranging
from Cabiúnas (Rio de Janeiro state)
to Vitória (Espírito Santo state),
from Vitória to Cacimbas (Espírito
Santo state), and from Cacimbas to
Catu (Bahia state), totalling 1,215
kilometers. This will expand Bra-
zil’s gas pipeline network to nearly
10,000 km, a measure considered a
key element of the company’s strate-
gic plan to more than double natural
gas consumption by 2011.

route selection and
structural design for the
golfinho gas export Pipeline
Marcelo José Barbosa Teixeira1, Claudio Roberto Mansur Barros1, Mônica de Castro Genaio1, Carlos Terencio Pires Bomfimsilva2, Vivianne
Cardoso Pessoa Guedes2, Janaina de Figueiredo Loureiro2
1
Petrobras S.A.; 2 Intec Engineering

The Golfinho Field is located in the over 470km² of area limited by the Acquisition of oceanographic data in-
Espírito Santo Basin, offshore Brazil, 60m and 1,380m isobaths (outer cluded deployment of two mooring
and will be producing 100,000bpd continental shelf and medium slope) lines along the pipeline route, one
of light oil through an FPSO moored and consisted of a single-beam ba- in 300m and the other in 1,300m
at a 1,350m water depth by 2006. thymetry for seafloor morphology depth, during a one-year period. The
The produced gas will be exported investigation, side scan sonar with mooring lines were equipped with an
onshore to the Gas Processing Unit, 100% percent coverage for superfi- acoustic current profiler for the top
in Cacimbas, via a 12-inch steel pipe- cial sediment distribution evaluation 100m and current meters with CTDs
line, which is fitted with a PLET at and a 3.5kHz sub-bottom profiler for distributed along the line. The lowest
the deep end to allow for subsea con- the investigation of subsurface struc- current meter was deployed at a 5m
nection to the flexible riser. tures. A geological and geotechnical distance from the seabed in order to
sampling campaign using a 6 meter quantify bottom currents, which are
The geophysical and oceanographic long piston-corer was also conducted crucial for pipeline design. Data ac-
survey started with the first option with coring locations selection based quisition for the shore approach area
proposed by the engineers. The im- on the geophysical records. Dating consisted of simultaneous measure-
mediate onboard evaluation of the of selected samples was done using ment of directional waves and current
data showed that the continental slope biostratigraphic methods. profiles, which was carried out using
of the area had an extremely complex an acoustic current profiler with wave
near-surface geology characterized by The integrated interpretation of all processing capacity deployed at 20m
the presence of canyons and ravines geophysical and geological data al- depth. Each month beach profiles and
associated with gradients up to 60° lowed the identification of the most sediment grain distribution were also
at the shelf break. Due to this reason critical factors such as high slopes quantified, in order to provide data
and the fact that the Golfinho field and areas of the seafloor dominated for numerical simulation of beach
was located in a region with few pre- by erosional processes, which should seabed profile evolution and support
vious studies, it was then decided to be avoided for the design route. pipeline burial specifications.
conduct a semi-regional scale high- Moreover, the understanding of the
resolution geophysical, geological and geological history of the area led to a structural design
geotechnical survey to aid the identi- qualitative slope stability evaluation
fication of natural and man-made ob- as a function of the geological envi- The most important activities with-
stacles that could represent any risk to ronment. The selected route corri- in the structural design were mate-
the structural integrity of the pipeline dor was determined considering all rial and corrosion assessment, wall
as well gain an understanding of the aspects that could represent risk to thickness design and pipelaying fea-
geological and oceanographic factors the pipeline integrity. This approach sibility analysis.
responsible for the features observed proved to be very useful by restrict-
on the seafloor. ing more detailed and time-consum- The entire pipeline was primarily
ing geotechnical investigation to the specified as seamless pipe with the
The entire survey was conducted be- final corridor considerably reducing minimum yield stress of 415MPa.
tween April and October 2004, with the final budget of the survey. The material and corrosion assess-


ment was then performed to check • Buckle propagation during instal- the design: select a thicker wall capa-
the suitability of adopting C-Mn lation. ble of resisting buckle propagation;
steel pipe to convey the gas contain- or weld buckle arrestor collars at a
ing 0.56% of CO2, and operating • Buckle propagation during selected spacing along the pipeline,
with the maximum pressure and depressurization. which are designed to prevent the
temperature of 230kgf/cm2 and propagating buckle from crossing
50ºC respectively at the PLET in a For the pipeline installed by the reel- over, limiting the pipeline damage
potentially wet environment. lay method, no concrete coating is extension to the design spacing be-
allowed and the selected wall thick- tween successive buckle arrestors.
The corrosion rates were then esti- ness of the pipe also needs to provide
mated following the De Waard and sufficient weight to ensure on-bot- A thicker wall that resists buckle
Milliams prediction model along the tom stability, mainly in shallow wa- propagation has been extensively de-
entire pipeline, considering the CO2 ters. In addition, the reel-lay method signed when the reel-lay method is
partial pressure, the operating tem- requires the pipe to be designed with applied, since it would be unpracti-
perature profile, the operating pres- sufficient wall thickness for spooling cal spooling the buckle arrestor col-
sure profile, and the pH values. In the pipeline onto the reel without lars onto the reel.
addition, the effect of corrosion in- achieving the critical strain. In this
hibitors with efficiency of 95% was case, the minimum nominal pipe In the Golfinho export pipeline, an
also considered as a reduction factor wall to comply with the critical strain additional requirement has been es-
for the corrosion rates. criterion is 15.9mm (0.625-inch). tablished, where the pipeline should
resist the buckle propagation at the
As a result, the total corrosion allow- The wall thickness design for deep- end of its lifetime, i.e. after the corro-
ance of 3.0mm was determined for water depths is mainly governed sion allowance has been consumed, so
water depths varying from 850m to by external hydrostatic pressure, the pipeline damage due to a potential
1,200m approximately and 1.6mm and the most critical phase for the local buckling would not propagate in
for shallower water depths. pipeline is during pipelaying, where case the pipeline is depressurized in the
the pipe may be subjected to a high operational phase. The required wall
In order to determine the required wall bending loading due to a loss of sur- thickness to resist propagation criteria
thickness for the pipeline, three failure face positioning of the pipelaying is presented in Figure 1.
modes were considered for the entire vessel. In case the pipe is designed
route: burst pressure; buckling due to with a thin wall, sufficient to resist The step at 850m for the depressur-
combined bending and hydrostatic the combined hydrostatic pressure ization condition is related to the
pressure; and buckle propagation, and bending, and an unexpected change in corrosion allowance. The
which were assessed based on the meth- buckle is formed, it will propagate 20.6mm (0.812-inch) has been pro-
odology proposed by DNV OS F-101. until a lower hydrostatic pressure is posed for water depth deeper than
These failure modes, when checked reached, and this may lead to dam- 100m water depth, since it is located
over the pipeline phases, i.e. pipelaying, age to a large section of the pipeline. in a rough seabed region and the in-
hydrotesting and operation, resulted in In order to avoid this situation, two crease in wall thickness will improve
the following load cases: strategies are typically adopted in the free span capability.

• Pressure containment during
operation

• Pressure containment during
hydrotesting.

• Local buckling due to combined
bending and external pressure
during installation

• Local buckling due to combined
bending and external pressure Figure 1 – Wall thickness design to resist propagation buckle.
during depressurization.

route selection and structural design for the golfinho gas export Pipeline

It was noted that using an 80-degree tial in deepwater depths to keep Geophysical survey has shown that
pipelaying ramp at 1,200m would the required top tension within the critical area along the pipeline
require a 1,472kN top tension to lay the vessel capacity. route was in the shelf break and
the 12-inch pipeline designed with in deepwater, specifically in water
25.4mm (1.000-inch) wall. In order • Higher ramp angles, however, depths ranging from 100 to 350m.
to minimize the top tension during are limited by the stress levels The route was optimized and the
pipelaying in deepwater depths, a con- observed at the sagbend region, number and size of free spans was
ceptual design for internal buckle ar- mainly in shallow water depths. drastically reduced. Due to the pres-
restors was investigated. For this case, ence of canyons, ravines and scarps,
a 22.2mm (0.875-inch) pipe would route optimization the pipelaying in this area should
be selected for deepwater, being suf- proceed under the lowest values of
ficient to resist buckle propagation The pipeline route can now be opti- tension as possible, in order to mini-
during installation. This pipe requires mized, i.e. re-routed to minimize the mize the residual tension along the
a 12-inch pipe with a thicker wall to number and size of free spans, by as- pipe, maintaining the free spans
be butt welded to the pipeline at a sessing alternative routes in the an- under the established limits of pipe
given spacing to function as a buckle ticipated rough regions, considering stress and spans lengths.
arrestor. The 31.8mm (1.250-inch) the seabed features observed from
wall thickness was selected based on the produced geophysical maps. The allowable free spans were de-
the DNV OS-F101 recommenda- First, the allowable free span needs termined based on available local
tions. The internal buckle arrestors to be determined, so the number information, which was not in a
could be welded within the stalks in of potential free spans may be esti- proper format for vortex induced
preparation for the spooling to avoid mated when assessing the alternative vibration analysis. The allowable
reducing pipelaying speed. routes. limits were then determined result-
ing in preliminary short free spans
Most of the pipeline route is, howev- In the proposed optimized route, which should be revised once the
er, located in shallow water depths, the number of free spans higher than oceanographic campaign provides
50km approximately, where the wall 1.0m was reduced to 19, and none is more realistic information for the
thickness is governed by on-bottom anticipated to be higher than 3m. fatigue analysis.
stability as shown in Figure 2.
final remarks acknowledgements
The assessment of the installation
feasibility was performed using the Little environmental information was The authors would like to thank
commercial Finite Element Software available for pipeline design, since the Petrobras pipeline design and ma-
Offpipe, which is dedicated for pi- Espírito Santo Basin is a new area of rine installation group for their sup-
pelaying analysis. The analysis was development in deepwater offshore portive work mainly during the geo-
performed by checking the stress Brazil. A geophysical and oceano- physical and oceanographic survey,
levels along the pipe related to the graphic campaign was then put for- and for their comments and sugges-
pipelaying geometry for the range of ward to provide rationale informa- tions kindly presented during the
the project water depths. tion for the pipeline design work. preparation of this paper.

It is worth emphasizing the follow-
ing aspects related to the selection of
pipelaying ramp angle:

• Bottom Tension is relevant for
the number and size of free spans,
and high ramp angles will result
in lower bottom tension, conse-
quently, allowing for free span
optimization.
Figure 2 - Required Wall Thickness for On-Bottom Stability.
• A higher ramp angle also requires
lower top tension, which is essen-

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