3. ACKNOWLEDGMENT
It is great pleasure to us as, a future engineer, to get an opportunity to
communicate and interact with a field during our training schedule at
Schlumberger, North Africa Geo Market Region (NAG).
First we would like to thank Mr. Badredine BOUHIRED recruiter and
university relationship manager for Algeria and Tunisia to arrange us this
training at Schlumberger and for his help and for his consistently
contribution to the success of the trainee in this company. .
We sincerely thank Mr. Yaman KADIMATI CTS Field services Manager for
allowing us at Coil tubing services (CTS), Algeria as a trainee.
We are especially grateful to Mr. Malek GUERFI CTS supervisor in charge
& the full CTS employees for extending their kind cooperation to us and for
all their technical advice, valuable guidance and timely encouragement in
making training.
A special thanks to field members and all the operators for help and guidance
they provide. It was indeed a wonderful experience to visit one of the leading
company in world.
4. 1-INTRODUCTION:
Schlumberger is the world’s leading supplier of technology, integrated project
management and information solutions to Customers working in the oil and gas
industry worldwide. Employing approximately 120,000 people representing over
140 nationalities and working in more than 85 countries, Schlumberger provides
the industry’s widest range of products and services from exploration through
production.
Schlumberger offers an extensive range of well intervention services and global
experience to extend the life of producing wells by improving performance or
providing access to stranded or additional hydrocarbon reserves. The innovative
intervention services conveyed on coiled tubing (CT) are designed to improve your
well and reservoir performance. CT applications include matrix and fracture
stimulation, wellbore cleanout, logging, perforating, nitrogen kickoff, sand control,
drilling, cementing, well circulation, and mechanical isolation.
Schlumberger product portfolio includes all the tools and services you need for
efficient and effective CT interventions.
2-Schlumberger:
Schlumberger was founded in 1926 by French brothers Conrad and Marcel
Schlumberger as the Société de prospection électrique (French: Electric
Prospecting Company). The company recorded the first-ever electrical
resistivity well log in Merkwiller-Pechelbronn, France in 1927. Today
Schlumberger supplies the petroleum industry with services such as seismic
acquisition and processing, formation evaluation, well testing and directional
drilling, well cementing and stimulation, artificial lift, well completions, flow
assurance and consulting, and software and information management. The
company is also involved in the groundwaterextraction and carbon capture and
storage industries.
The brothers had experience conducting geophysical surveys in countries such
as Romania, Canada, Serbia, South Africa, the Democratic Republic of the
Congo and the United States. The new company sold electrical-measurement
mapping services, and recorded the first-ever electrical resistivity well
log in Merkwiller-Pechelbronn, France in 1927. The company quickly expanded,
logging its first well in the U.S. in 1929, in Kern County, California. In 1935,
the Schlumberger Well Surveying Corporation was founded in Houston, later
evolving into Schlumberger Well Services, and finally Schlumberger Wireline
& Testing. Schlumberger invested heavily in research, inaugurating the
Schlumberger-Doll Research Center in Ridgefield, Connecticut in 1948,
contributing to the development of a number of new logging tools. In
1956, Schlumberger Limited was incorporated as a holding company for all
Schlumberger businesses, which by now included American testing and production
company Johnston Testers.
5. Over the years, Schlumberger continued to expand its operations and acquisitions.
In 1960, Dowell Schlumberger (50% Schlumberger, 50% Dow Chemical), which
specialized in pumping services for the oil industry, was formed. In 1962,
Schlumberger Limited became listed on the New York Stock Exchange. That same
year, Schlumberger purchased Daystrom, an electronic instruments manufacturer
inSouth Boston, Virginia which was making furniture by the time the division was
sold to Sperry & Hutchinson in 1971. Schlumberger purchased 50% of Forex in
1964 and merged it with 50% of Languedocienne to create the Neptune Drilling
Company. The first computerized reservoir analysis, SARABAND, was introduced
in 1970. The remaining 50% of Forex was acquired the following year; Neptune
was renamed Forex Neptune Drilling Company. In 1979, Fairchild Camera and
Instrument (including Fairchild Semiconductor) became a subsidiary of
Schlumberger Limited.
Schlumberger established the first international data links with e-mail in 1981. In
1983, Schlumberger opened their Cambridge Research Center in Cambridge,
England and in 2012 it was renamed the Schlumberger Gould Research
Center after the company's former CEO Andrew Gould.
The SEDCO drilling rig company and half of Dowell of North America were
acquired in 1984, resulting in the creation of the Anadrill drilling segment, a
combination of Dowell and The Analysts' drilling segments. Forex Neptune was
merged with SEDCO to create the Sedco Forex Drilling Company the following
year, when Schlumberger purchased Merlin and 50% of GECO .
In the 1970s, the company's top executives in North America were relocated
to New York City.
In 1987, Schlumberger completed their purchases of Neptune (North America),
Bosco and Cori (Italy), and Allmess (Germany). That same year, National
Semiconductoracquired Fairchild Semiconductor from Schlumberger for $122
million. In 1991, Schlumberger acquired PRAKLA-SEISMOS, and pioneered the
use of geosteering to plan the drill path in horizontal wells.
Schlumberger acquired software company GeoQuest Systems in 1992. With the
purchase came the conversion of SINet to TCP/IP and www capability. In the
1990s Schlumberger bought out the petroleum division, AEG meter, and ECLIPSE
reservoir study team Intera Technologies Corp. A joint venture between
Schlumberger and Cable & Wireless resulted with the creation of Omnes, which
then handled all of Schlumberger's internal IT business. Oilphase and Camco
International were also purchased.
In 1999, Schlumberger and Smith International created a joint venture, M-I L.L.C.,
the world's largest drilling fluids (or mud) company. The company consists of 60%
Smith International, and 40% Schlumberger. Since the joint venture was prohibited
by a 1994 antitrust consent decree barring Smith from selling or combining their
fluids business with certain other companies, including Schlumberger, the U.S.
District Court in Washington, D.C. found Smith International Inc. and
Schlumberger Ltd. guilty of criminal contempt and fined each company $750,000
6. and placed each company on five years probation. Both companies also agreed to
pay a total of $13.1 million, representing a full disgorgement of all of the joint
venture's profits during the time the companies were in contempt.
In 2000, the Geco-Prakla division was merged with Western Geophysical to create
the seismic contracting company WesternGeco, of which Schlumberger held a
70% stake, the remaining 30% belonging to competitor Baker Hughes. Sedco
Forex was spun off, and merged with Transocean Drilling company in 2000.
In 2001, Schlumberger acquired the IT consultancy company Sema plc for
$5.2 billion. The company was an Athens 2004 Summer Olympics partner, but
Schlumberger's venture into IT consultancy did not pay off, and divestiture of
Sema to Atos Origin was completed that year for $1.5 billion. The cards division
was divested through an IPO to form Axalto, which later merged with Gemplus to
form Gemalto, and the Messaging Solutions unit was spun off and merged with
Taral Networks to form Airwide Solutions. In 2003, the Automated Test
Equipment group, part of the 1979 Fairchild Semiconductor acquisition, was spun
off to NPTest Holding, which later sold it to Credence.
In 2004, Schlumberger Business Consulting was launched. Based in Paris, it is the
company's management consultancy arm.
In 2005, Schlumberger purchased Waterloo Hydrogeologic, which was followed
by several other groundwater industry related companies, such as Westbay
Instruments, and Van Essen Instruments. Also that year, Schlumberger relocated
its U.S. corporate offices from New York to Houston.
In 2006, Schlumberger purchased the remaining 30% of WesternGeco from Baker
Hughes for US$2.4 billion. Also that year, the Schlumberger-Doll Research Center
was relocated to a newly built research facility in Cambridge, Massachusetts to
replace the Ridgefield, Connecticut research center. The facility joins the other
research centers operated by the company in Cambridge, England; Moscow,
Russia; Stavanger, Norway; and Dhahran, Saudi Arabia.
In 2010, the acquisition of Smith International in an all stock deal valued at $11.3
billion was announced. The sale price is 45.84-a-share price was 37.5 percent
higher than Smith closing price on 18 February 2010. The deal is the biggest
acquisition in Schlumberger history. The merger was completed on August 27,
2010. Also announced in 2010 were Schlumberger plans to acquire Geoservices, a
French-based company specializing in energy services, in a deal valued at $1.1
billion, including debt.
In 2014, Schlumberger announced the purchase of the remaining shares of SES
Holdings Limited (“Saxon”), a Calgary-based provider of international land
drilling services, from First Reserve and certain members of Saxon management.
The transaction is subject to customary closing conditions, including the receipt of
regulatory approvals. Schulmberger had a minority share in Saxon previously.
7. 3-QHSE:
Schlumberger has a long-standing HSE commitment to the highest standards for
the health and safety of our employees, customers, and contractors as well as to the
protection of the environment in the communities in which we live and work.
The Schlumberger HSE Management System defines the principles by which we
conduct our operations worldwide with regards to health, safety, and the
environment.
Management communicates the HSE philosophy to all employees, customers,
contractors, and third parties associated with our business, and each Schlumberger
organization must provide positive evidence of conformance to the system.
The HSE Management System model comprises eight interrelated components:
commitment and leadership and accountability
policies and objectives
organization and resources
contractor and supplier management
risk management
business processes
performance monitoring and improvement
audits and reviews.
These are continuously improved by conformance checks
on day-to-day standards and procedures (controls)
on the management system (correction)
through modifications to the management system (improvement).
Schlumberger captures its own performance data via QUEST, an online system
that provides immediate consolidation of HSE information. Accessible by all
employees, QUEST monitors reporting of HSE events and Risk Identification
Reports (RIRs), facilitates investigations and records audits, manages remedial
work plans (RWPs), shows improvement suggestions, posts recognitions, tracks
HSE training, and facilitates HSE reports and data analysis.
As a business and a community of individuals Schlumberger is connected to a
number of global challenges. As the focus of our Global Citizenship framework,
we have chosen the six issues to which we make the most significant contribution
in the natural course of our activity. Four of these issues are HSE related:
minimizing the environmental impact of our business operations, promoting
driving safety, preventing malaria, and raising awareness of HIV and AIDS.
8. 4-Coiled Tubing:
a- What is (CT):
Coiled Tubing (CT) has been defined as any continuously-milled tubular product
manufactured in lengths that require spooling onto a take-up reel, during the
primary milling or manufacturing process. The tube is nominally straightened prior
to being inserted into the wellbore and is recoiled for spooling back onto the reel.
Tubing diameter normally ranges from 0.75 in. to 4 in., and single reel tubing
lengths in excess of 30,000 ft. have been commercially manufactured. Common
CT steels have yield strengths ranging from 55,000 PSI to 120,000 PSI.
The coiled tubing unit is comprised of the complete set of equipment necessary to
perform standard continuous-length tubing operations in the field. The unit
consists of four basic elements:
-Reel - for storage and transport of the CT
-Injector Head - to provide the surface drive force to run and retrieve the CT
-Control Cabin - from which the equipment operator monitors and controls the CT
-Power Pack - to generate hydraulic and pneumatic power required to operate the
CT unit
11. b- Well Control Equipments:
Proper well control equipment is another key component of CT operations, given
that a majority of these operations is performed in the presence of surface wellhead
pressure. Typical CT well control equipment consists of a BOP topped with a
stripper (high pressure CT units have two strippers and additional BOP
components). All components must be rated for the maximumwellhead pressure
and temperature possible for the planned field operation.
The stripper (sometimes referred to as a packoff or stuffing box) provides the
primary operational seal between pressurized wellbore fluids and the surface
environment. It is physically located between the BOP and the injector head. The
stripper provides a dynamic seal around the CT during tripping and a static seal
around the CT when there is no movement. The latest style of stripper devices are
designed with a side door that permits easy access and replacement of the sealing
elements, with the CT in place.
The BOP is situated beneath the stripper, and can also be used to contain wellbore
pressure.
CT BOP is designed specifically for CT operations. It consists of several pairs of
rams, with each ram designed to perform a specific function. The number and type
of ram pairs in a BOP are determined by the BOP configuration: single, double, or
quad. A quad system is commonly used in most operations.
The four BOP rams, from top to bottom and their associated functions are:
-Blind ram - seals the wellbore when the CT is out of the BOP
-Shear ram - used to cut the CT.
-Slip ram - supports the CT weight hanging below it (some are bi-directional and
prevent the CT from moving upward).
-Pipe ram - seals around the hanging CT Standard CT BOPs also contain two
equalizing ports, one on each side of the sealing rams. It also has a side outlet
between the slip and shear rams. This outlet can be used as a safety kill line. BOPs
are available in a range of sizes, and normally follow the API flange sizes.
c- CT benefits:
While the initial development of coiled tubing was spurred by the desire to work
on live wellbores, speed and economy have emerged as key advantages for
application of CT. In addition, the relatively small footprint and short rig-up time
make CT even more attractive for drilling and work over applications.
Some of the key benefits associated with the use of CT technology are as follows:
�Safe and efficient live well intervention
�Rapid mobilization and rig-up
�Ability to circulate while RIH/POOH
�Reduced trip time, resulting in less production downtime
�Reduced crew/personnel requirements
�Cost may be significantly reduced
12. Coiled tubing can also be fitted with internal electrical conductors or hydraulic
conduits, which enables down hole communication and power functions to be
established between the BHA and surface. In addition, modern CT strings provide
sufficient rigidity and strength to be pushed/pulled through highly deviated or
horizontal wellbores. This enables successful execution of down hole operations
that would be impossible to perform with conventional wireline approaches, or
would be cost prohibitive if performed by jointed-pipe.
d- CT field applications:
The use of CT has continued to grow beyond the typical well cleanout and acid
stimulation application. This growth can be attributed to a multitude of factors,
including advances in CT technology and materials as well as the increased
emphasis on wellbores containing a horizontal and/or highly deviated section.
The CT application list (below) is provided as a "thought-provoker", to illustrate
additional operations where CT could be of benefit in your future fieldwork.
5-NEST (New Employee Safety Training)
(20-03-2015) to (22-03-2015)
Our Training have started by three days Safety Training for New Employee NEST,
in this training our instructors make us discover many benefits things starting by
introducing Schlumberger , Review of QHSE policies , Standards , pocket HARC ,
SIPP , Fire prevention , Mechanical lifting ………..
(23-03-2015) to (24-03-2015)
Assist in maintenance of coiled tubing unit and control equipments: BOP, stripper,
and reel to get in touch with work environment and to be familiar with coil tools
and equipments.
13. Our experience in the field
A-Scale blaster (WI-CTS operation):
1-Introduction:
25th
March 2015 (5:30 morning): we got out from base MD2 to 2N-central in
Hassi-Messsaoud field OMN-70.
OMN-70 in an oil producer vertical well located in 2N-central in Hassi
Messaoud field and drilled on 21/04/1994.OMN-70 is completed with 41/2
“tubing
till 3220.57m and then 41/2
”liner till TD 3362Bm.this program is considering of
performing a coiled Tubing intervention on the well to remove any solids across
the liner and intensive tube clean wash in order to recover the production.
2-objectives:
The main proposed intervention is to remove any solids from the liner by doing
a scale blaster; followed by a tube clean wash aimed to remove any rust and
soluble in acid from the wellbore in order to recover the production.
3-operation procedure:
-mobilize equipment to OMN-70.
-hold pre-rig up meeting with all personnel and discuss the following points:
1-safety on location and around equipment.
2-muster point and head count.
3-rig up procedure.
-rig up CTU;CTPU and N2U;flush lines and CT reel with water and test all
surface lines to 5000psi, as per SCHLUMBERGER and SONATRACH standards.
-MU bottom whole assembly on coiled tubing pipe end.
-pressure at all surface lines and bop blind ram against the swab valve to PT-
1@5000Psi (pt1 determined as the lesser of 1.5 times MPWHP or the working
pressure of the lowest rated equipment).
-pressure test the jet blaster on surface prior to perform pt-2
-prior to opening the well, with all equipment rigged up, perform pt-2
pressure test @ 5000psi(pt-2 determined as the lesser of pt-1 pressure or coil limit
collapse pressure)
-check the wellhead pressure, equalize pressure if necessary .SONATRACH
supervisor will line up the valves and open the well.
-start RIH at speed of 5m/min while going through the x-mast tree. Once CT
depth is 30m.increase, the CT speed to 20 m/min while pumping Nitrified treated
water at minimum rate to keep positive CT pressure.
14. -perform pull test as per CoilLIFE fatigue and as required (every 300 to
700m)
Tubing size on drift ring On nozzle head
When
jetting
When not
jetting
When jetting When not
jetting
3-1/2 in or smaller 1000 lbs 2500 lbs 500 lbs 2500 lbs
4 in or larger 500 lbs 1000 lbs 300 lbs 1000 lbs
Reduce the CT speed while passing through the restrictions to 5m/min.
Depth(m) Restriction type ID(in)
3206.17 m VM OTIS L “R” nipple ID 3.688
3210.45 m VM OTIS L “RN” nipple ID 3.456
-if there is any kind of restriction while RIH through the tubing, POOH 5 m
and engage the triplex pump and start pumping at 1.2-1.4 BPM and 20LPM
nitrified treated water. Let the Pcirc stabilize and returns to be steady at surface.
-start mixing 11m3 of sterling beads slurry as per following concentration:
Chemicals For 1m3 For 11m3
J457 gelling agent 10 Kg 110 Kg
T163 sterling beads 40 Kg 440 Kg
-continue RIH, when full returns at surface proceed to start cleaning out
without exceeding maximum loads on the BHA.
-make sure to have sterling beads @ nozzle with CT @ 3270m.
-RIH at 3-5 m/min (especially the first run) while pumping at 1.1 BPM
and 500 scf/min and always observes the returns. Every 10 m penetrated POOH 5
m, alternate the fluid as per previous recommendation.
-depending on the nature of the fill proceed to pump 10 BBL every 30 m
of the viscous pill, followed by the N2 slug at 600 scf/min. the ROP to be
controlled not to exceed the axial loading values.
-make 1 pass up and down from 3270 m and 3340 m to ensure the liner
is completely cleaned from any solids.
-Tag Td, POOH 5m and pump 2m3 of gel followed by 2m3 of treated
water at rate 1.5
BPM than displace with 1 to 2 m 3 of nitrogen at maximum rate.
-follow with circulating 3 m3 of nitrified treated water and then stop
pumping water and switch to 7.5 % HCL tube clean wash as per the below
treatment instructions.
-from 3270 m to 3340m,start injection of washing fluids with
increasing pressure to 4000 psi and reciprocating CT up-down as following
schedule making 1 pass:
15. NO Fluid Vol m3 Cum
vol m3
Pump
rate(BPM)
N2
rate(SCF/min)
CT
SPEED(m/min)
Interval(m)
1 TW 2%
NH4CL
4 4 1.2 600 4 3340-3270
2 TC
HCL7.5%
4 8 1.2 600 4 3270-3340
6 TW 2%
NH4CL
4 12 1.2 600 4 3340-3270
4 TC
HCL7.5%
4 16 1.2 600 4 3270-3340
-Continue RIH until TD @ 3360m, displace the CT with 4m3 of treated
water then pump 2m3 of gel pill followed by 2m3 of nitrogen at maximum rate.
-Decrease N2 rate to 15-20 LPM and keep POOH until clear return is
observed at surface.
-stop CT @ 2500 m for kick off if needed.
-POOH to surface
-Once CT at surface, SONATRACH representative will secure the well.
SCHLUMBERGER personnel will bleed off pressure from equipment.
- SCHLUMBERGER personnel will bleed of the pressure and hand
over the well to SONATRACH rep on location.
GEL PILL CONCENTRATION FOR
CHEMICALS AND ADDITIVES 1m3
J457 Gelling Agent 4 Kg
J258 Ammonium Chloride 20 Kg
H2O Fresh water 980 Lt
Table 1: Gel based fluid
Treated water 2% NH4CL CONCENTRATION CONCENTRATION
CHEMICALS AND
ADDITIVES
1 M3 40 M3
Water 990 Liters 39600 Liters
J285 Ammonium Chloride 20 Liters 800 liters
Table 2: treated water
Sterling beads Concentration Concentration
CHEMICALS AND
ADDITIVES
1 m3 11 m3
J285 Ammonium Chloride 20 Kg 220 Kg
J457 Gelling Agent 10 Kg 110 Kg
T163 Sterling beads 40 Kg 440 Kg
Table 3: sterling beads slurry
16. HCL 7.5% Concentration Concentration
CHEMICALS AND
ADDITIVES
1 M3 8 M3
HCL 33% 202 Liters 1616 Liters
A261 corrosion inhibitor 6 Liters 48 Liters
A201 aid inhibitor 10 Liters 80 Liters
F103 surfactant 2 Liters 16 Liters
L058 Iron control 1.5 Kg 12 Kg
water 780 Liters 6240 Liters
Table 4: Tube clean
4-Equipment and personnel requirements
-One 1.75 Coiled tubing unit with crew
-One fluid pump unit with crew
-One nitrogen pump with crew
-One batch mixer with crew
-Two citterns of treated water and acid
-Two full Jet blaster BHA
5-Well Schematic (fig 1)
17. B-Reformate Clean Out Operation
1-Introduction:
(26th
March 2015) to (27th
March 2015) (5:30 morning): we got out from base
MD2 to zone HTF-10 in Hassi-Messsaoud.
The well is completed with 7” @ 3298.5 and 4 ½” production tubing @3247
m and then 4 ½” liner until TD 3478m. The well top of cement is 3476 MTR.
2-objectives:
The objective of the coiled tubing intervention is to clean out the well with
reformate to remove the organic deposit in the tubing which restrict flow passage
in order to put the well back to production.
3-description of reformate:
Petroleum refinery naphtha is transformed into reformat by catalytic reforming.
This process involves the reconstruction of low-octane hydrocarbons in the
naphtha into more valuable high-octane gasoline components without changing the
boiling point range. Naphtha and reformate are complex mixtures of paraffin,
naphthalene, and aromatics in the C5-C12 range.
4-operation procedure:
-mobilize equipment to zone HTF-10
-hold pre-rig up meeting with all personnel and discuss the following points:
1-safety on location and around equipment.
2-muster point and head count.
3-rig up procedure.
-rig up CTU;CTPU and N2U;flush lines and CT reel with water and test all
surface lines to 5000psi, as per SCHLUMBERGER and SONATRACH standards.
-MU bottom whole assembly on coiled tubing pipe end:
1-CT connector
2-DFCV
3-straight bar
4-high radial jetting nozzle
-pressure at all surface lines and bop blind ram against the swab valve to
PT-1@5000Psi (pt1 determined as the lesser of 1.5 times MPWHP or the working
pressure of the lowest rated equipment).
-prior to opening the well, with all equipment rigged up, perform pt-2
pressure test @ 5000psi(pt-2 determined as the lesser of pt-1 pressure or coil limit
collapse pressure).
18. -check the wellhead pressure, equalize pressure if necessary .SONATRACH
supervisor will line up the valves and open the well.
-start RIH at 6m/min through wellhead w/o pumping,CT@200m start N2
pumping nitrified treated water @ 0.3-0.5BPM and 15LPM.
-Make pull tests every 300-700m as required.
-if any sediment tagged, POOH 5m switch to reformat and start jetting
(1.2 BPM and 20LPM).RIH at minimum speed and continue clean out operation.
-make sure you have returns at all times while RIH otherwise stop CT and
wait for returns increase N2 rate if required up to 20-25lpm be sure there are
returns @ 3000m prior to proceed RIH.
-for every 200m of clean out pump 5bbls of foam (1.2 BPM and 25LPM),
in order to carry any expected hard sediment.
-switch to reformat prior to pass thru the nipples @ 3000m,reduce CT
speed to 5m/min increase the pumping rate 1.2 BPM and N2 20 LPM.
-continue RIH CT, perform pull test before going thru the nipples at
3230.34m and 3246m decrease the speed to 5-7m/min ,and record the weight as a
reference.
-continue clean out until 3455m with reformat while using mainly foam.
-make several passes across the liner up and down until pumping the total
volume of the reformat 27m3
for every 50m for cleaning pull out 20m and circulate
the organic deposits to the flare line.
-arriving at 3455m,pump 2m3
of gel (J457@4Kg/m3
) and follow with 2m3
of nitrogen at max rate, and start kicking the well.
-POOH to 3000m and kick off the well if required, keep POOH below
15m/min to avoid passes the fluid in the way out.
-if oil returns are observed at surface and well is confirmed flowing, begin
POOH to surface.
- if oil returns aren’t observed when CT reach 3,000m, keep pumping
nitrogen and observes the well, if necessary stop the coil @2500m and start the
kicking off the well.
-Once CT at surface, SONATRACH representative will secure the well.
SCHLUMBERGER personnel will bleed off pressure from equipment.
- SCHLUMBERGER personnel will bleed of the pressure and hand over
the well to SONATRACH rep on location
5- Equipment and personnel requirements
1-1.75in coiled tubing unit with crew
2-one N2 pump with 12m3
N2 tank with crew.
3-one pumping unit with crew.
4-one cittern of reformat
5-two citterns for treated water and chemicals.
6-12m3
N2 tank
19. 6-treatment fluids
Treated water 2% NH4CL Concentration for
Chemicals and additives 1 M3
50 M3
Water 990 Kg 49500 Liters
J285 clay stabilizer 20 Kg 1000 Kg
Table1: treated water
foam Concentration for
Chemicals and additives 1 m3
water 996 Liters
F100 6 Liters
J285 clay stabilizer 20 Kg
Table 2: foam
gel Concentration for
Chemicals and additives 1m3
2m3
J457 gelling agent 4 Kg 8 Kg
J285 clay stabilizer 20 Kg 40 Kg
H2O fresh water 980 Liters 1960 Liters
Table 3: Gel
100%pure reformat blend Concentration for
Chemicals and additives 1 M3
27 M3
100% reformat blend 1,000 Liters 27,000 liters
Table 4: reformat
7-Well Schematic (fig 2)
20. Our experience in the laboratory
(28-03-2015) TO (30-03-2015)
STIMULATION LABORATORY PROCEDURES
A- IDENTIFICATION OF OILFIELD SCALES
INTRODUCTION
Scales are precipitated mineral deposits. They can precipitate in the tubing,
perforations and/or formation. Scale deposition occurs during production because
of the lower temperatures and pressures encountered in or near the wellbore area.
Scales can also form by mixing of incompatible waters, formation water and a
fluid either filtrate or injection water.
SAFETY
Goggles and protective clothing should be worn when working with acid.
EQUIPMENT
•Hydrochloric acid (~15%)
•Hot plate / water bath
•U104 or U42
•Test tubes / glass beakers
•Magnet
PROCEDURE
Follow the decision tree, below, to identify the unknown scale sample
22. B-GEL BREAK TEST USING A FANN35 VISCOMETER
INTRODUCTION
The purpose of this test is to determine the time taken for a breaker to reduce
the viscosity of a gel to a specified value. A gel that has been degraded to a
viscosity of <60cP at 40 sec-1 at the fracture temperature is considered broken
enough to flow back from the fracture.
SAFETY
Normal safety procedures should be observed i.e. Laboratory jacket, suitable
gloves and safety glasses with side protection.
CHEMICALS AND EQUIPMENT
• Sample of the linear gel to be tested.
• Cross-link solution (with known addition rate)
• Breaker to be tested
• 2 of 500 mL fann stainless steel thermocups with one cover/lid (plastic or glass)
• 2 of 500ml plastic beakers
• Water bath
• FANN 35 viscometer with R1-B2 rotor-bob combination and Spring F1, with
500ml type heated cup + dial thermometer
• Glass rod/stirrer
• Thermometer
• Timer
PROCEDURE
1. Prepare a stock solution of the breaker to be tested by adding 2.3965 g
of breaker made up to 100mL with distilled water.
1mL of stock solution per 200 mL of frac fluid equals 1 lb per 1000 gals of frac
fluid (if high breaker loadings (>5lbm) are required prepare a stronger
solution).
2. Prepare one litre of linear frac fluid e.g. WF100. See EATC Procedure F02.
3. Place 400mL of the prepared linear fluid into one of the 500ml plastic
breakers.
4. Inject the stock breaker solution into the beaker so as to obtain the
desired breaker concentration range. Stir or pass the fluid between beakers to
disperse the breaker into the fluid. 1mL of stated breaker solution is
equivalent to 1lb/1000 gals if added to 200mls of linear fluid.
23. 5. For HTD or D gel systems add the required amount of cross-linker solution into
the beakers and pass fluid between beakers while observing the crosslink.
6. Pour the cross linked gel into one of the stainless steel metal cups and place in
a pre-heated water bath set approximately 5-10°F above the required
temperature, start the timer. Cover the metal container with a glass or plastic cover
to help the heat up rate and reduce evaporation.
7. Pour 400ml of water into the second metal cup and place in a thermo
cup preheated to the test temperature. Place the thermo cup under the
fann35 and rotate at 100rpm between gel viscosity readings. Before making
a gel viscosity measurement (every 10 minutes) dry the bob and sleeve
(rotate at 600rpm for a few seconds and dry the outside with paper) before
swapping the metal cups over, make the measurement and then swap back. This
ensures the bob is kept at or near the correct temperature throughout the test and
does not cool the gel below the required temperature during the
measurement of viscosity.
8. Stir the fluid (metal container in water bath) every 3-5 minutes with
glass stirring rod to ensure good heat distribution. Measure the gel viscosity
and temperature every 10 minutes, recording the results on the attached
worksheet. Report the time elapsed for the fluid to reach the required
temperature. The viscosity should be measured at 100rpm (with B2 this is
equal to a shear rate of 38sec-1). Viscosity is calculated using the following
equation.
Viscosity @ 40sec-1 = Dial reading * 26.75
9. When the fluid is of a water-like composition or its viscosity has dropped below
60cP @ 40 sec-1, it is classed as fully broken.
10. The time required for the fluid to break completely is classed as the
break time for that particular breaker loading.
11. When the testing is complete, remove the beaker with the broken gel from the
water bath and allow it to cool to ambient temperature, re-measure the
viscosity on the Fann35 Viscometer to check for any re-heal after cooling.
24.
25. In the field again
Reformat wellbore cleanout and squeeze treatment
1-Introduction:
(31th
March 2015) TO (02th
APRIL 2015) (5:30 morning): we got out from
base MD2 to zone RDC-9 in Hassi-Messsaoud.
RDC-9 is an oil producer well completed with 4 ½” tubing new van until
3577.42 m TR and 4 ½” slotted liner from 3577.5mrt until 3919mRt, the well had
a reduction in production due to an organic deposition in the well bore and surface
equipment.
2-treatmnet objective:
Maintain the productivity of the well RDC-9 and remove the organic deposit in
the tubing, which restrict flow passage.
3-pressure test:
LPT 300psi, low-pressure test for 5 min.
PT-1 5,000psi, pressure test BOP blind ram for 10 min.
PT-2 5,000psi, pressure test stripper and CT with BHA for 10 min.
MPWHP 3,200psi, identify causes of additional pressure.
CPL 3,500psi, immediate steps to control and reduce WHP.
MWCP 5,000psi, apply BOP controls contingency procedures.
4-Operating procedure:
Day 1: Tube clean
-tag stripper, zero depth as RKB reference depth (RKB=10.1m) check all recording
and monitoring devices.
-energize the stripper to a minimum pressure of 5000psi.use the pump to test the
stripper to 5,000 psi. stop the pump check that all pressure gauges have the same
pressure reading.
-bleed pressure down to 1,500psi through the flow tee or return line from the
wellhead.
-run in hole coiled tubing at 6m/min (circulating 2%NH4CL water at ideal rate)
until clear of the wellhead valves and increase speed to maximum of 25 m/min.
performing pull test every 500m while checking the coillife and compare weights
with coilcade weights.
26. - always keep 200-300 psi backpressure WHP in the chock.
-pump 3bbl of viscous pill every 15m follow by N2 slug @600 SCF/min. the ROP
to be controlled don’t exceed the axial loading values specifiedabove.
-Make two passes up and down across the slotted liner (3361m to 3474 m VM) to
ensure whole cleaning of the interval.
-continue with tube clean treatment while reciprocate the CT across slotted liner
interval with speed of 3m/min pump rate 1BPM and 600scfm with chock the well
to around 300 psi as follow:
Fluid type Passes Volume m3 Pump rate BPM Nitrogen rate
Pure reformat 3750m to 3738m 1 2 500
Nitrified tube
clean
3738m to 3750m 2 2 500
Nitrified trated
water
3750m to 3738m 1 2 500
Pure reformat 3738m to 3750m 1 2 500
Nitrified tube
clean
3750m to 3738m 2 2 500
Nitrified trated
water
3738m to 3750m 1 2 500
-CT@ TD pump 1m3 of gel pill followed by 1m3 of N2 at maximum rate in order
to bottom up the treatment to the flare line and then reduce the N2 rate while
POOH till be sure all treatment circulated out of the well.
-POOH to 2500 m and keep pumping N2 if required to ensure that all the spent
acid is followed back to the flare line.
Day 2: reformat matrix squeeze treatment
-when CT is at a 5m above the slotted-liner, increase pumping rate to wash slotted
liner.
-Once TD is reached pullout to the end of the liner and continue filling up the well
with reformat in order to prepare it for reformat solvent squeeze.
-Once the well is confirmed to be full set the CT at 3740m, then close the well and
start squeezing the remaining volume of pure reformat (25m3) at maximum rate.
-once the reformat has been displaced out of the reel into formation with 40.3 bbl
of 2% NH4CL inhibited treated water; stop pumping.
-start POOH to surface while maintaining the squeeze pressure by periodically
kicking in the pump to sustain the pressure.
-reformat to be left to soak over-night with the well shut in.
-bleed off pressure rig down injector head from the wellhead
-as long as water is neutral, can leave it overnight in the reel.
27. Day 3: kick off
-record SIWHP prior to open the well.
-start RIH at 6m/min once you passed the surface elements increase the speed to
20m/min.
-stop CT at each 250m and stay kicking off with N2 for 10 to 15 min at a rate of
350 scf/min.
-pull test at each 500m or according to real time coilife. Reduce CT speed to
6m/min at restrictions.
-once at the depth 1000m increase pump rate to 500scf/min adjust nitrogen rate
according to the return and circulation pressure.
-perform kick off until depth 2800m.
-with CT at depth, 2800m continue unloading the well and observe WHP for
natural flow.
-on completion of kick off, POOH CT to surface while pumping N2 at minimum
rate.
-once CT at surface stop N2 close the well record last FWHP and SIWHP.
5-Equipment and personnel requirements:
-One each 1.75 in CT unit with 1 crew.
-One each fluid pump unit with 1 crew.
-One each nitrogen pump unit with 1 crew (equipped with 12m3 nitrogen storage
tank).
-Two citterns for water transportation (30m3 each).
-Three citterns for reformat transport (27 m3).
-One truck for transporting chemical and accessories.
-BHP assembly.
6-fluids description:
2%NH4CL treated water
8.38 ppg(2%) NH4CL treated
water
Concentration for Concentration for
Chemicals and additives 1 M3
40 M3
Ammonium chlioride 20 Kg 800 Kg
Fresh water 983 Lt 39320 Lt
HiVis Gel pill
Gell pill Concentration for Concentration for
Chemicals and additives 1 M3 1 M3
Ammonium chlioride 20 Kg 20 Kg
Fresh water 983 Lt 983 Lt
J457 Gelling agent 4 Kg 4 Kg
28. 7.5% Tubeclean
Tubeclean Concentration for Concentration for
Chemicals and additives 1 M3 4 M3
HCL 33% 202 Liters 808 Liters
A261 Corrosion inhibitor 6 Liters 24 Liters
A201 aid inhibitor 10 Liters 40 Liters
F103 surfacant 2 Liters 8 Liters
L058 iron control 1.5 Kg 6 Kg
water 780 Liters 3120 Liters
100% Pure reformat blend (2 citterns from SLB and 1 cittern from hall)
100% reformat blend Concentration for Concentration for
Chemicals and additives 1 M3 81 M3
Reformat solvent 1,000 Liters 81,000 Liters
7- well schematic (fig3)
29. CONCLUSION :
As we will graduate soon from the University we would like to say that this
training program is an excellent opportunity for us to get to the ground level and
experience the things that we would have never gained through going straight into
a job. I am grateful to Schlumberger for giving us this wonderful opportunity. The
main objective of the training is to provide an opportunity to trainees to identify,
observe and practice how engineering is applicable in the field.
It is not only to get experience on technical practices but also to observe
management practices and to interact with fellow workers. It is easy to work with
sophisticated machines, but not with people. The only chance that a trainee has to
have this experience is the training period. We feel we got the maximum out of
that experience. In addition, we learnt the way of work in an organization, the
importance of being punctual, the importance of maximum commitment, and the
importance of team spirit.
We have gained lots of knowledge and experience needed to be successful in a
great engineering challenge, as in our opinion, Engineering is after all a Challenge,
and not a Job.
