Introduction to offshore oil and gas surface facilities, including drilling rig types, topside and substructures, jacket, compliant tower, jack up, gravity based structure, fpso, fso, semi submersible, tlp, spar, wellhead platform, processing platform, pipeline, and surface facilities selection

1. Introduction to Offshore
Oil and Gas Surface Facilities
By Puput Aryanto Risanto
17 November 2015
Rev.1 4 October 2016

2. Upstream Oil & Gas Life Cycle
ExplorationExploration
• Activities to search for oil & gas deposit on the
certain location beneath the earth surface
AppraisalAppraisal
• Activities to define the oil & gas volume and
characteristic more precisely after discovery
• Activities to build the subsurface & surface facilities
DevelopmentDevelopment
• Activities to build the subsurface & surface facilities
to produce oil & gas safely and efficiently
ProductionProduction
• Activities to extract, process, and export oil & gas
as per contract agreement
AbandonmentAbandonment
• Activities to plug wells permanently, remove surface
facilities, and restore the field as per initial state

3. Exploration
Once the Oil Company is granted a permit to conduct the
business from the government (through host authority),
they must start with exploration.
Exploration is an activities to detect oil & gas presence
beneath the earth surface by means of gravity survey,
magnetic survey, and seismic reflection survey.
Seismic surveys work on the principle of the time it takes
for reflected sound waves to travel through matter
(rock/soil) of varying densities and then translated into a
for reflected sound waves to travel through matter
(rock/soil) of varying densities and then translated into a
profile of the earth soil & rock layers, sometimes called
seismic imaging.
In offshore, seismic survey is done by a seismic vessel.
Finally, when an indication of oil & gas presence
(prospect) exists based on the evaluation, it must be
followed by a “drilling” activity to conclusively determine
the presence or absence of oil & gas inside the reservoir
(a subsurface “pool” where fluids trapped between layer
of soils & rocks).

4. Seismic Vessel

5. Seismic Imaging

6. Drilling
Drilling is activities to create a hole from the earth surface to the
reservoir target in the earth subsurface.
Based on the purposes, drilling can be divided into :
Exploration : to find the oil & gas reservoir
Appraisal : to further confirm the reservoir volume and characteristic
Development : to produce oil & gas from the reservoir
Injection : to inject fluids (gas,water,chemical,etc) into the reservoir
A set of machines for drilling is called drilling rig.A set of machines for drilling is called drilling rig.
Based on the structure housing the drilling equipment set,
offshore drilling rig can be classified into :
1. Bottom supported
Self-contained platform rig
Tender Assisted Drilling (TAD) rig
Jack Up (JU) rig
Inland barge (swamp-barge) rig
2. Floating
Semi-submersible rig
Drill ship

7. Drilling Rig (Sketch-1)

8. Drilling Rig (Sketch-2)

9. Development
Once significant hydrocarbon volume is confirmed, field
development plan / Plan of Development (FDP/PoD) will
be proposed to monetize the oil & gas deposit.
FDP shall contain :
Method of oil & gas volume calculation including
uncertainties
Method of hydrocarbon recovery and estimated recovered
volume (number of oil & gas that can be lifted through out
Method of hydrocarbon recovery and estimated recovered
volume (number of oil & gas that can be lifted through out
the field life / contract period)
Surface facilities to extract, process, and export oil & gas
Operation and Maintenance philosophy
Cost, Schedule, and Economic calculation
Abandonment Plan
FDP is subject to host authority (government appointed
body for upstream oil & gas regulation) and shareholders
approval

10. Surface Facilities Definition
In offshore oil & gas industry, term “Surface” is defined
above the mud-line, or simply seabed / ocean floor /
bottom sea (including several meter below seabed).
Surface Facilities can be defined as a set of systems
and equipments to extract, process, and export oil &
gas in a safe, controlled, and efficient way which aregas in a safe, controlled, and efficient way which are
located on the surface.
Generally, surface facilities consists of 2 sections :
Substructure : a steel structure to support the upper part
(called topside) including the foundations.
Topside : an integral part of steel deck (can be single or
stacked) and all equipment placed on it, supported by a
substructure.

11. Topside and Substructure
Topside
Substructure
Pipeline

12. Substructure Types
In general, substructure can be divided into :
1. Fixed Type (bottom supported the seabed)
Jacket
Compliant Tower
Jack UpJack Up
Gravity Based Structure
2. Floating Type (float on the sea surface)
Mono/Single Hull
Semi Submersible (Semi Sub)
Tension Leg Platform (TLP)
SPAR

13. Fixed Substructure - Jacket
Welded tubular space frame with near vertical legs with bracing system between
legs. Piles will be inserted inside legs, hence the tubular frame will act like a “jacket”
covering piles. Jacket can have 3 up to 12 legs, but majority is 4 legs. Jacket is the
most common offshore substructure. The deepest jacket is Shell Bullwinkle at 412
m water depth on US Gulf of Mexico / GoM.

14. Fixed Substructure - Compliant
Flexible (compliant) tubular space frame with flexible elements to mitigate natural
forces. This tower can be free standing or supported by guy wires. The deepest
installation is Chevron Petronius (US GoM) at 623 m below sea level.

15. Fixed Substructure – Jack Up
Movable floating hull and three or more legs, which can be moved up and down
relative to hull. For operational mode, legs must be lowered to the seabed, then
raising the hull to the required elevation. Water depth for jack up installation depends
on the legs length, but normally below 100 m. Jack up can be easily moved and is
normally used on a marginal / small field with short production life (below 5 years),
sometimes also called MOPU (Mobile Offshore Production Unit).

16. Fixed Substructure – Gravity Based
Fixed structures that are held-in-place by its own weight plus any contained ballast,
majority constructed from steel-reinforced concrete, normally called CONDEEP
(concrete deep water structure), majority installed in Norway. The deepest structure
is Statoil Troll-A (Norway North Sea) at 303 m water depth.

17. Floating Structure – Monohull
Monohull is a type of vessel with only one hull. The hull may be in the form of normal
vessel (ship-shaped) or cylindrical (circular like a bowl) secured by sets of moorings
and anchors. It can have a liquid storage, hydrocarbon processing, and liquid
transfer to tanker capability, hence called FPSO (Floating Production Storage
Offloading). If no processing facility, it is called FSO (Floating Storage Offloading).
The deepest one is FPSO Stones (US GoM) at 2896 m water depth.

18. Floating Structure – Semi Sub
Semi submersible is floating structures with several columns (vertical hull) and
pontoons (horizontal hull) which can be controlled in such a way that pontoons
become fully submerged and column partially submerged, while the topside remains
above the water line, and secured with spread moorings and anchors. This will
increase the stability and station keeping. Semi sub platform sometimes called sFPS
(semi-sub Floating Production Station), FPS, or FPU (Floating Production Unit). The
deepest FPS is Chevron Jack/St. Malo (US GoM) at 2134 m water depth.

19. Floating Structure – Tension Leg Platform
TLP is a floating structure, normally in the form of semi-submersible, which is
vertically moored to anchors by a set of tubular steels called tendons. The tendons is
constantly in tension by floating structure buoyancy and tensioner system. The
tension leg keeps the platform very stable, hence surface wellhead can be installed.
The deepest TLP is Chevron Big Foot (US GoM) at 1581 m water depth.

20. Floating Structure – SPAR
SPAR is floating platform with a deep-draft (most of the section is submerged) large
vertical cylinder hull, completed with heavy ballast on the bottom to ensure center of
gravity is below center of buoyancy, secured with spread moorings and anchors. The
deep-draft design makes it very stable and suitable for surface wellhead. SPAR can
also store liquid. The deepest SPAR is Shell Perdido (US GoM) at 2450 water depth.

21. Summary of Substructure Types

22. Surface Facilities Function
Surface facilities function can be described as :
Extraction : Facilities to extract oil & gas from the reservoir
into surface in a safe and controlled manner.
Processing : Facilities to process “raw oil & gas / well
stream” into “treated” crude oil and/or natural gas as per
customer requirement.
Exporting : Facilities to export treated/processed oil and/orExporting : Facilities to export treated/processed oil and/or
gas to customer receiving point.
In offshore platforms, those functions are done by :
Extraction : Wellhead Platform (WHP)
Processing : Central Processing Platform (CPP)
Exporting : Pipeline, F(P)SO, FLNG
In addition, Living Quarter is provided to accommodate
operation & maintenance crew 24/7.

23. Wellhead Function
Wellhead : A termination point of a well (a series of tubular
steel running from the surface up to certain target on the
reservoir, referred as the bottom hole) on the surface that
provides the structural and pressure-containing interface
for the drilling and production equipment.
During drilling, surface pressure control is provided by a
Blow Out Preventer (BOP).
Once drilling completed, surface pressure control isOnce drilling completed, surface pressure control is
replaced by a “Christmas Tree” installed on top of the
wellhead, with isolation and choke valves to control the
flow of well fluids during production.
Normally, wellhead & Christmas tree is located on the
platform and can be easily operated by man, called surface
wellhead or dry tree.
However, for deep water or when platform installation is
considered not cost-effective, wellhead & Christmas tree
may be located on the seabed, called subsea wellhead or
wet tree.

24. WHP, surface wellhead, & dry tree
Surface
wellhead &
Christmas tree

25. Subsea wellhead & wet tree

26. Processing Function
Not like many people think that “oil & gas” reservoir contains
only oil and/or gas, actually it always contain oil, gas, water, and
sometimes other contaminants like nitrogen (N2), carbon dioxide
(CO2), hydrogen sulfide (H2S), mercury (Hg), and salt.
Oil & gas molecules are actually constructed from the same
elements, Hydrogen (H) and Carbon (C), hence referred as
Hydrocarbon. Oil is hydrocarbon mixtures which form liquid at
room temperature (25oC), whereas gas is hydrocarbon mixtures
which form gas at room temperature.which form gas at room temperature.
Well fluids coming from the reservoir are actually a mixture of all
above fluids in a high pressure and temperature.
Meanwhile, the customers (downstream industry) require
separate treated oil (crude oil) & gas (natural gas) for further
processing.
Processing function is to separate oil, gas, and water, then treat
oil and gas to meet customer specification, and treat water for
overboard discharge (release to the sea) or re-inject to the
reservoir.

27. Processing Block Diagram

28. Process System
It is defined as all the system required to process well stream into crude oil and
natural gas.
In general, it consists of :
Separation : to separate well stream into oil, gas, and water
Gas Dehydration : to further remove water from gas
Gas Treatment : to remove contaminants from gas
Gas Conditioning : to regulate gas condition like temperature & dew point
Gas Compression : to compress (increase pressure & reduce volume) gas soGas Compression : to compress (increase pressure & reduce volume) gas so
it can travel in a long distance to customer receiving point
Gas Metering : to measure the volume of gas export as a basis of company
revenue
Oil Dehydration : to further remove water from oil
Oil Stabilization : to further remove gas from oil
Oil Desalting : to remove salt content from oil
Oil Pumping : to pump (increase pressure only without reducing volume) oil so
it can travel in a long distance to customer receiving point
Oil Metering : to measure the volume of oil export
Produced Water Treatment : to remove oil, gas, and other contaminants from
produced water until meeting certain criteria for disposal to the sea

29. Utility System
It is defined as all the system required to support process system. It is as important as
process system itself, since system malfunction may reduce, stop, or even endanger
the production. In general, it consists of :
Power generation & distribution : to generate & distribute electrical power to the
electrical equipment
Instrumentation : to measure and monitor process and utility parameters & provide
input to the control system
Control : to regulate process and non-process system as per requirement
Heating : to provide heat to hydrocarbon, i.e. crude oil heating for easier flow
Cooling : to remove heat from hydrocarbon, i.e. gas cooling after compression
Instrument Air : to compress air and distribute it for instrumentation & control purpose
Utility Air : to compress air and distribute it for general purpose, i.e. for compressed
air powered hand tool
Gas Fuel : to condition natural gas for gas powered engine, i.e. Gas Turbine
Generator
Diesel Fuel : to store and distribute diesel fuel for diesel powered engine, i.e.
Emergency Diesel Generator

30. Utility System - continued
Drain : to collect and store any excess process and non-process liquid
Fresh & Potable Water : to treat sea water into fresh (plain but not drinkable) and
potable (drinkable) water
Fire & Gas : to detect fire & gas leakage and provide warning and input to control
system
Fire Water System : to provide fire water for fire extinguishing
Emergency Shutdown : to provide facilities to safely stop the process (shutdown) in
case of any emergencycase of any emergency
Flare : to provide a safe way to remove and burn excess gas
Vent : to provide a safe way to remove excess gas without burning it
HVAC (Heating Ventilation and Air Conditioning) : to provide conditioned air to
enclosed room, i.e. control room
Telecommunication : to provide telecommunication and remote control/monitoring of
remote facilities
Crane and Mechanical Handling : to lift and move heavy equipment within platform or
from/to boat
Marine (only for floating structure) : to control stability and movement of floating
structure

31. Living Quarter (LQ)
In general, accommodation or LQ has facilities :
Bedroom : number of beds defines maximum number of people can stay
Galley : also called dining room where people gather for meal and rest
Kitchen : for safety reason, only electric stoves allowed in offshore platform
Meeting Room : teleconference capability with onshore office is a must
Office : normally, only Offshore Installation Manager (OIM) has dedicated room
Bathroom : normally shared male bathroom, only OIM and VIP guest room have
own-bathroom inside the bedroom
Clinic : sufficient medication and facility to manage emergenciesClinic : sufficient medication and facility to manage emergencies
Multi Purpose Room : can be used for sport, recreation, and praying
Helideck : for helicopter/chopper take off and landing, with/out refueling facility
Boat Landing : for boat/vessel landing to transfer personnel or light
equipment/material
Emergency Life Boat : for emergency escape if platform damage due to fire or other
disaster
Radio Room : for telecommunication equipment installation
Material Storage : to store spare equipment, spare parts, and consumables
Control Room : to remotely control and monitor process parameters
Maintenance Workshop : to maintain and repair equipment, but normally only minor
repair due to limited facility

32. CPP-only side view illustration

33. CPP with drilling & LQ illustration

34. Exporting Function
Crude oil and natural gas will be evacuated from offshore
platform to onshore receiving facility (ORF) through a
pipeline.
Pipeline is a long pipe for conveying fluids (oil and/or gas) .
Offshore pipeline will be placed on the seabed.
Offshore pipeline may be insulated to keep fluids warm andOffshore pipeline may be insulated to keep fluids warm and
coated with concrete to add stability and protection.
If oil pipeline is considered too expensive or no available
ORF, offshore storage may be considered using FSO,
FPSO, or subsea storage, then stored oil exported to oil
shuttle tanker.
Same case for gas, offshore gas storage may be
considered using Floating Liquefied Natural Gas (FLNG),
then stored liquefied gas exported to LNG shuttle tanker.

35. Surface Facilities Selection
Selection will be based on several factor, mainly :
Number and type of wells
Production capacity and field life
Water depth and seabed condition
Nearby and onshore receiving facilities
Oil & gas evacuation strategy
Health Safety Environment philosophy
Operation & Maintenance philosophy
Contractor capability
Local regulation
Cost and schedule
Technology availability and maturity
Concept selection will be conducted during
development stage and the result will be part of FDP.

36. Separate bridge-linked jacket

37. Integrated WHP-CPP-LQ in single jacket

38. Separate bridge-linked jacket with FSO

39. FPSO with wet tree

40. Semi submersible with wet tree

41. Tension Leg Platform with dry tree

42. Have you ever imagine…???
Troll A, the largest and tallest object ever moved by mankind. Overall height is
472 m (20 m taller than Petronas Twin Towers) and the weight is 683,600 tons

43. Have you ever imagine (again)…???
Katie Melua, a
British female
singer, performed
a concert at the
bottom of Troll A
platform at 303 m
below sea level
as a celebration
of 10 yearsof 10 years
operation by
Statoil in 2006,
break another
record for the
deepest
underwater
concert on the
earth.

45. About the Author
Puput Aryanto Risanto had more than 12
years experience in oil & gas industry.
Currently he is working for Premier Oil Natuna
Sea B.V. in Jakarta, Indonesia. Previously he
worked for Petronas Carigali Sdn. Bhd. in KL,
Premier Oil Natuna Sea B.V. in Jakarta and
Total E&P Indonesie in Balikpapan, Indonesia.Total E&P Indonesie in Balikpapan, Indonesia.
His expertise included project engineering & management,
joint venture management, engineering & construction
management, & electrical engineering-construction-
inspection. This presentation was small contribution to
educate the public during low oil price environment. He can
be contacted at aryantorisanto@yahoo.com