2. TETRA Offshore Services
Leading single
Leading single-
-source provider of well abandonment
source provider of well abandonment
and decommissioning services in North America
and decommissioning services in North America
Offshore, Onshore, Inland, and Subsea
Offshore, Onshore, Inland, and Subsea
• Project Engineering & Management
• Heavy Lift
• Diving & Marine
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• Diving & Marine
• Subsea P&A
• Rigless Offshore P&A
• Topside and Subsea Cutting
• Onshore P&A
• Electric Wireline
• Inland Workover, P&A, and Drilling Rigs
3. Project Management … the Backbone
of a Successful Project
Integrated Project Management (PM) is vital to the success of any
project. The PM requirements for offshore decommissioning are
different from those of construction projects. While both vary in
degrees of complexity with any given project, the coordination of
activities, vessels, tools, and skills complement each phase of a
productive solution for a decommissioning project.
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productive solution for a decommissioning project.
This presentation is a general overview of how decommissioning
projects are executed from conception to completion. Requirements
may vary from region to region and project to project.
5. Pre-Planning
• Client interface
• Scope of work definition
• Drawings and well diagrams
• Schedule
• Site access
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• Site conditions (platform crane,
accommodations, etc.)
• Site visit
• Potential for re-use
• Removal and disposal options
6. Contractual and Regulatory
Contractual Issues
• Legal and governmental requirements
• Master Service Agreement (MSA)/project contract with client
• Contract structure:
Lump sum
Day rate
Turnkey
• Contract terms – payment, extra work clarifications,
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indemnification, weather clause, etc.
• Liabilities, insurance
• Dispute resolution
Regulatory/Environmental Obligations
• Permits, licenses, consultations
• Regulations – below mudline severing, reefing
and salvage requirements, vessel specifications, etc.
• Documentation – pre-abandonment surveys
• Environmentally sensitive areas
7. Engineering and Project Planning
• Project Risk Assessment/Concept Safety Evaluation
• Engineering – preliminary and detailed
• Pre-Abandonment Surveys
Geophysical; subsea
Environmental
Structural
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Structural
Process equipment
• Well Abandonment Program
Treatment of the annuli between casing strings
Cutting and retrieval of upper casing strings
(refer to Petroleum Production Regulations)
Well plug configurations (drawings, depths, etc.)
8. Engineering and Project Planning
• Decommissioning of Platform
Electrical power
Fire and safety equipment
Accommodation and life support systems
Decommissioning services
Oil and gas systems
Inject inert gas into all applicable systems
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Inject inert gas into all applicable systems
(refer to process equipment)
• Topside Removal
Heavy lift vessels
Cargo/Material barges
Supply vessels
Anchor Handling Tugs (AHT)
Safety/Standby vessels
Helicopter services to transport personnel
9. Engineering and Project Planning
• Jacket Removal
Survey jacket down to mud line
Disconnect, rig-up, and remove pipeline spools and umbilicals
Verify cut lines on jacket
Sever jacket legs with cutting equipment
Apply appropriate rigging equipment
Lift jacket onto material barge and secure in place
• Onshore Disposal
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• Onshore Disposal
Dispose of hazardous materials in accordance with local
rules and regulations
Demolition, recycle, and/or re-use module
• Pipeline Abandonment
Legal requirements for pipeline removal – total removal,
trenching to adequate depths, or leave in-situ (method of
removal should not cause adverse effect on marine
environment)
Decommissioning of pipeline – clean and purge all internal
hydrocarbons and dispose of according to regulations
10. Project Execution Plan
• Project Risk Assessment
• Project organization, including roles and
responsibilities
• Equipment required (may vary depending of type of
project):
– Heavy lift vessels
– Diving Support Vessels (DSV)
– Rig or rigless P&A
– Severing systems
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– Severing systems
– Material barges
– Utility vessels
– Survey
• Logistics support and marine base
• Local subcontractors and vendors
• Perform scope of work
• Debris clearance
• Pre- and post-decommissioning monitoring and
maintenance
• Supporting studies and surveys
11. Quality and HSE Considerations
• HAZ I.D.
• Health, Safety, Environment
(HSE) manual
• Quality manual
• Standard Operating Procedures
(SOP) for various services
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(SOP) for various services
• Record retention
• Emergency preparedness and
evacuation
12. Integrating Services
• Project management training
• Coordinating scope of services:
– P&A
– Severing
– Diving
– Heavy lift
– Wireline
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– Wireline
• Project reporting
– Daily updates
o Conference call
o Physical and electronic reports
– Final report and documentation
– Job completion certificate
15. CASE STUDY
B Background
• 10,000 square foot, 4,100-ton concrete barge built
in 1992
• Provided storage for oil produced from 4-pile platform
constructed above it
• Out of commission in 55 feet of water
B Challenges
• Massive size of concrete barge: 90’x104’x14’ tall and
weight of approximately 4,100 tons – largest barge of
its type and size in the GOM
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its type and size in the GOM
• Water depth of 55 feet – barge sat in deeper water than
any other concrete barge in the GOM
• Verification of cleanliness and elimination of all
hydrocarbons from oil storage tanks had to be achieved
prior to reefing
• First time experience for TETRA Offshore Services to
clean and reef barge of this type
• Prevention of water seeping back into ballast tanks that
would increase weight of concrete barge on crane
• De-ballasting concrete barge had to be precisely
controlled for a balanced lift operation
17. CASE STUDY
B Phase 1
• Performed thorough inspection of platform and
barge
• Pumped out and cleaned two oil storage tanks
and verified that no hydrocarbons remained
• Removed valves in ballast compartment and
all ballast and vent pipes plugged
B Phase 2
• Removed deck, mini jacket, and piles, which
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• Removed deck, mini jacket, and piles, which
were placed on a material barge
• Held material barge in field until three wells
were severed during phase 7
18. CASE STUDY
B Phase 3
• Removed manway hatches from 14 ballast tanks and
single ballast compartment
• Installed dewatering pump packages on manway
hatches
• Attached slings from crane on TETRA’s DB-1 Derrick
Barge to four pad eyes on corners of concrete barge
• Pumped water out of 14 ballast tanks and single ballast
compartment
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compartment
• Pulled concrete barge from seabed to surface where
remaining water was pumped from ballast tanks
• Barge floated freely to surface on its own – no lift
bags needed
19. CASE STUDY
B Phase 4
• Constantly observed ballast tanks for possible
water seepage back into ballast tanks
• Installed tow line and anchor rigging to concrete
barge
B Phase 5
• Utilized two tug boats that towed concrete barge
20 miles south to designated reef site
• Anchored concrete barge over reef site
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• Recovered anchors to the DB-1 Derrick Barge
• Anchored DB-1 in position along side of concrete
barge
B Phase 6
• Removed pump packages from manway hatches
• Stretched hoses from pumps to four largest ballast
tanks
• Pumped water into four largest ballast tanks and
allowed concrete barge to sink to the seabed at
reef site in a water depth of 74 feet
20. CASE STUDY
B Phase 7
• Re-installed manway hatches
• Back-welded bolts on manway hatches underwater
to secure hatches, preventing future entry into
concrete barge
B Phase 8
• Returned DB-1 Derrick Barge to HI 208
• Severed three wells 15 feet below mudline
• Placed conductors on material barge along with
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• Placed conductors on material barge along with
deck, mini jacket, and piles, which were all
transported to onshore salvage yard
B Phase 9
• Performed site clearance verification by trawling
1,320-foot diameter circle from center of where
platform had stood in the HI 208 location – returning
the site to its original state
• Submitted documentation to regulatory agencies
21. CASE STUDY
Results
Cleaning and reefing the submerged concrete
barge and decommissioning the four-pile
platform satisfied the requirements of both the
client and the Mineral Management Service.
Cleared of all structures and debris, the HI 208
Block of the Gulf of Mexico was returned to it
original condition, and the reefed concrete
barge now serves as a habit for marine life at
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barge now serves as a habit for marine life at
the reef site.
The integration of TETRA’s Heavy Lift Team,
EOT Cutting Services, and EPIC Divers &
Marine enabled the operation to be completed
on time and without incident.
TETRA Offshore Services . . .
restoring the environment one
field at a time.
