offshore oil and gas overview
TRANSCRIPT
Offshore Oil and Gas Production System
Nguyễn Quang MinhMechanical Engineer
Vietnam Oil and Gas GroupPetroVietnam Gas Joint Stock Corporation
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Content
I. Overview
II. Offshore Platform
III. Crews
IV. SCADA
V. Fire & Explosion Protection
VI. Environment Protection
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WELL PLATFORMS
PROCESS PLATFORMS
ONSHORE TERMINALS
DATA/SCADA
POWER
FLUID ( OIL/GAS/WATER )
INJECTION WATER
LIFT GAS
FSO
OIL TO REFINERY
GAS TO CONSUMERS
OIL
GAS
WELL
WELL FLUID
INJ WATER
LIFT GAS
UMBILICAL(DATA/WELL CONTROL
WELLS/CONNECTED WELL PLATFORM
SEPARATION MODULE OIL/GAS/WATER‐GAS COMPRESSION AND DEHYDRATION MODULE
SEA WATER TREATMENT FOR WATER INJECTION
PRODUCED WATER TREATEMENT MODULE
POWER GENERATION
UTILITIES WATER/SUPPLIES‐LIVING QUARTERS
DRILLING/WELL SERVICING RIG MODULE
WELLS
WELL TESTING
PRODN OPTIMIZATION
WELL CONTROL
WELL SERVICING
TELEMETRY / SCADA
WELLS
OIL PRODUCERS
GAS PRODUCERS
INJECTION WELLS
I. OVERVIEW
OFFSHORE PRODUCTION SYSTEM A SCHEMATIC‐
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THE MAJOR ELEMENTS OF OFFSHORE PRODUCTION SYSTEM
• WELLS (SUBSEA/PLATFORM WELLS)
• WELL PLATFORMS/WELL SERVICING RIGS
• FEEDER SUBSEA PIPELINES
• PROCESSING PLATFORMS
• EXPORT PIPELINES FOR OIL/GAS
• TANKERS FOR EVACUATION OF OIL
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II. OFFSHORE PLATFORMS- A large structure used to house workers and machinery needed to
drill and/or extract oil and natural gas through wells in the ocean bed- Though as technology improves, drilling and production in deeper
waters becomes both feasible and profitable. - Many platforms also have remote wellheads attached by umbilical
connections, these may be single wells or a manifold centre for multiple wells
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A. Type of offshore platforms
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• Fixed Steel Structure: Giàn cố định• Compliant Tower: Tháp mềm• Jack-up Platform: Giàn tự nâng• Concrete Gravity Base Structure: Giàn trọng lực• Tension Leg Platform (TLP): Giàn chân căng• Semi-submersible Vessel: Giàn nửa chìm nửa nổi• Floating Production System: Hệ thống khai thác nổi• Spar Platform: Giàn Spar• Subsea system
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1. Fixed Steel Structure - The traditional offshore structure
consists of weld steel, tubular framework or jacket to support the topside facilities. Piles driven into the seafloor secure the jacket.
- The Fixed Steel Structures are restricted to shallow water developments with water deep about 1500 ft.
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2. Compliant Tower- They have a steel tubular jacket that is used to
support the topside facilities and they are secured to the seafloor with piles.
- Unlike fixed platforms, compliant towers yield to the water and wind movements in a manner similar to floating structures. The jacket of a compliant tower has smaller dimensions than those of a fixed platform.
- Compliant towers are designed to sustain significant lateral deflections and forces, and are typically used in water depths ranging from 1,500 to 3,000 ft
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3. Jack-up Platform- The Jack-up Platform consists of
a triangular shaped (sometimes rectangular), box section barge fitted with three (sometimes four) moveable legs which enable the vessel to stand to the seabed in water depths of up to 120 m (400 ft).
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4. Concrete Gravity Base Structure- The Concrete Gravity Base Structure have
been constructed using a base manufactured from reinforced concrete.
- The design of base includes void spaces or caissons to provided the structure with a natural buoyancy which will enable it to be floated to field development location. Once on location the void spaces are flooded on the seabed whilst the topside modules are lifted into place.
- The void spaces then used as storage compartments for crude oil, or filled with permanent iron ore ballast.
- The colossal weight of concrete structures obviates the need to install foundation piles, hence the name gravity base structure.
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5. Tension Leg Platform (TLP)- A Tension Leg Platform (TLP) is a buoyant
platform held in place by a mooring system.- The mooring system is a set of tension legs
or tendons attached to the platform and connected to a template or foundation on the seafloor. The template is held in place by piles driven into the seafloor. This method dampens the vertical motions of the platform, but allows for horizontal movements.
- TLPs are used in water depths from 1500 ft to 7000 ft.
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6. Semi-submersible Vessel- Have twin hulls (columns and
pontoons) of sufficient buoyancy to cause the structure to float
- It can be moved from place to place; can be ballasted up or down by altering the amount of flooding in buoyancy tanks; they are generally anchored by combinations of chain during drilling and/or production operations, though they can also be kept in place by the use of dynamic positioning.
- Semi-submersibles can be used in water depths from 200 to 10,000 feet.
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7. FPSO- FPSOs are large ships equipped
with processing facilities and moored to a location for a long period.
- The main types of floating production systems are:
• FPSO (floating production, storage, and offloading system)
• FSO (floating storage and offloading system)
• FSU (floating storage unit).
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8. SPAR Platform• A spar is a type of floating oil
platform typically used in very deep waters, and is named for logs used as buoys in shipping that are moored in place vertically.
• A spar platform consists of a large diameter, single vertica cylinder supporting a deck. The cylinder is weighted at the bottom by a chamber filled with a material that is denser than water to lower the center of gravity of the platform and provide stability. Spars are anchored to the seabed by way of a spread mooring system with either a chain-wire-chain
• 10 000 ft
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9. Subsea system
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B. Facilities of Offshore Platform
- Wellhead Platform- Process Platform- Platform Complex
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1. Wellhead Platform (WHP)- A wellhead platform includes an integrated deck, utility systems,
wellhead systems, living quarters, a helideck and drilling facilities.- WHPs are normally unmanned. They are designed to be operated
remotely and visited during routine inspection and maintenance activities.
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2. Process Platform
- Separation (Oil, Gas and Produced water)
- Gas Compression & dehydration- Produced Water Conditioning- Sea water processing &
injection system
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3. Platform Complex
Ekofish Complex
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III. Crews• OIM (offshore installation manager) is the ultimate authority during his/her shift and makes the essential
decisions regarding the operation of the platform.• Operations Team Leader (OTL)• Offshore Operations Engineer (OOE) is the senior technical authority on the platform• PSTL or Operations coordinator for managing crew changes• Dynamic Positioning Operator, navigation, ship or vessel maneuvering (MODU), station keeping, fire and
gas systems operations in the event of incident• 2nd Mate Meets manning requirements of flag state, operates Fast Rescue craft, cargo ops, fire team ‐
leader.• Ballast Control Operator also fire and gas systems operator• Crane operators to operate the cranes for lifting cargo around the platform and between boats.• Scaffolders to rig up scaffolding for when it is required for workers to work at height.• Coxwains for maintaining the lifeboats and manning them if necessary.• Control room operators Especially FPSO or Production platforms.‐• Catering crew will include people tasked with performing essential functions such as cooking, laundry
and cleaning the accommodation.• Production techs for running the production plant• Helicopter Pilot(s) live on some platforms that have a helicopter based offshore. The helicopter flight
crew transports workers to other platforms or to shore on crew changes.• Maintenance technicians (instrument ,electrical ,mechanical )
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IV. SCADA- SUPERVISORY CONTROL AND DATA
ACQUISITION- Gather necessary DATA from a
REMOTELY LOCATED Oil/Gas well and Well Platform with the help of Field Transmitters & RTU and send it to the DATA GATHERING & ANALYSIS point.
Sensor at well platform
RTUs, PLCs
Computer
Actuator at well platform
SCADA schematic
PressureTempLever…
ValvePump…
CPUMonitorServer
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SCADA Management
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Benefit of SCADA• 24 hrs online monitoring control from onshore center• Historical Data and trending helps in Troubleshooting• Ability to close wells remotely during emergency.• Better Production optimization of individual wells• Instant alerts in case of Well closures, ESD, FSD and control panel
failure• Optimum utilization of Manpower for attending to well problems• Reduction in number of physical visits to well platforms resulting in
optimization of Helicopter sorties.• To observe slugging in pipelines.• Lift gas allocation for each well
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V. FIRE AND EXPLOSION PROTECTION
- Unpredictable- Cause: Human and Natural
Disater- Fire & Explosion Protection- Risk Management
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- Emergency Shutdown (ESD) system+ Levels of Shutdown+ Isolation Valve Requirements- Depressurization, Blowdown and Venting
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Fire Detection & Suppression SystemDetection system- Gas Detection- Fusible Plug- Fire Detection- Smoke Detection- Heat Detection
Suppression system- Fire water pump- Water Sprinkler- Dry Chemical- CO2 Extinguisher- AFFF SYSTEM
Escape / Abandon- Scape Ladder- Scramble Net- Life Ring- Life Raft- Life Boat- Jumping Rope
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VI. Environment Protection
