Subsea Field Development

Case Studies:

Client: Mariner Energy
Location: "Apia" Garden Banks 73

Scope of Work: Oceaneering recently completed a turnkey subsea tieback. Oceaneering was responsible for the entire scope of work under a single contract minus the drilling and completion work scopes. The offset distance from the tree to the platform was approximately 2.7 miles and water depths ranged from 500 to 750 feet. A direct hydraulic control system was used to control a single subsea well. Dual coiled tubing flowlines was used to produce the well. The subsea tree system was managed by Oceaneering along with the production topside facilities.

Client: ATP Oil & Gas Corporation
Location: High Island Block A253

Scope of Work: Oceaneering recently completed a turnkey subsea tieback of a well to a platform in HI A270. Water depths over the 6.4-mile tieback distance range from 130 ft. at the well to 160 ft. at the platform. The contract workscope was comprised in two phases, with the second being dependent on the successful result of drilling operations. The Phase 1 work included the modification and refurbishment of a mudline tree owned by Oceaneering; rental of an installation/workover control system and provision of service technicians; an engineering hazard route survey to be performed through Oceaneering's joint venture agreement with John Chance; and engineering and project management services. Phase 2 workscope included provision of a direct hydraulic production control system, including the hydraulic power unit and chemical injection system, provision of a Multiflex thermoplastic subsea control umbilical; installation of the flowline, control umbilical, subsea connections, the platform riser and pull-tube, and overall project management and integration, including interface management, quality assurance, system integration testing and procurement.

Client: Sonangol P&P
Location: Kiabo Block 4 Angola

Scope of Work: Oceaneering provided a single subsea tree system. The well was tied back to Oceaneering's FPSO Ocean Producer. The well was located within about 100 meters of the stern of the FPSO. The tree system included a tubing completion spool, tubing hanger, tree, tree cap and the refurbishment of all tree system running tools. Water depth was 120 ft. An existing flowline and umbilical was disconnected from another well in the field and re-connected to the new well.

Client: Kerr-McGee Oil & Gas Corporation
Location: West Cameron Block 638 Gulf of Mexico

Scope of Work: Oceaneering completed a turnkey subsea tieback. The well was tied back to a platform in West Cameron 648. The scope of work included the supply and installation of a coiled tubing flowline, control umbilical, flowline and umbilical risers, hydraulic control system, and related interface hookup hardware. Oceaneering also performed systems engineering for the project and supervised the overall systems integration testing. Oceaneering manufactured all of the hardware, with the exception of the flowline and risers, and provided the flowline and umbilical installation equipment, including reels, straightener, stinger and vessel, for the 3.7-mile tieback. A remotely operated vehicle was supplied to monitor the installation operations, while a WASP atmospheric diving system was used to connect the flowline and umbilical to the subsea tree. Water depth in the area was approximately 400 ft.

Client: Shell Offshore
Location: "Mensa" Mississippi Canyon 730, 731, 686, & 687 Gulf of Mexico

Scope of Work: Oceaneering was contracted in October 1996 to perform an engineering design study for a specialized hydrate remeditaion system scheme. The objectives of the study were to determine the best method of deploying the system, design an emergency release sub-system, generate installation and operational procedures and analyze the overall system for technical feasibility. In addition, Oceaneering generated conceptual equipment designs which eventually lead to Shell's awarding Oceaneering a contract to design, manufacture, test and store a large portion of the deployment system.

Client: Marathon Oil Company
Location: "Oyster" Ewing Bank 917 Gulf of Mexico

Scope of Work: Oceaneering was awarded a considerable scope of material supply for the project including the following: supply of a direct hydraulic subsea production control system with HPU sized to handle requirements for the related Arnold project; an 18,500-ft electro-hydraulic subsea control umbilical and flying leads; connection hardware for the control umbilical and production flowline; installation of the umbilical; installation of the jumper connecting the flowline to the subsea tree and installation of an I-tube on the platform.

Client: Shell Offshore
Location: "Popeye" Green Canyon 116 Gulf of Mexico

Scope of Work: Oceaneering provided engineering support for system integration test (SIT) program and offshore installation planning. Prepared SIT execution plan, test procedures, schedules, work scopes, and site layouts. Assisted in carrying out SIT program doing schedule tracking, cost tracking, daily reporting, test result documentation, coordinating the photographic and video documentation and administrating the SIT site office. Prepared final SIT documentation report. Coordinated the preparation, review, editing and issuing of offshore installation procedures related to the completion rig activities.

Client: Exxon U. S. A
Location: "Zinc" Mississippi Canyon 355 Gulf of Mexico

Scope of Work: Oceaneering provided turnkey services for the recovery and repair of the subsea control umbilical connecting its Zinc template and manifold in MC 355 to the Alabaster platform in MC 397. Water depth at the site is about 1,500 ft. Oceaneering provided project management and engineering services, developed all procedures for recovery, repair and reinstallation of the umbilical, supplied hardware to effect the repair, and supervised the offshore execution of the work. Oceaneering provided two ROVs for the offshore operations, one aboard the primary repair vessel chartered for the job and the second aboard our diving and ROV support vessel Ocean Service. The work was accomplished in just 3-1/2 days of lump-sum offshore work during the latter part of August 1996.

Client: Amoco Production Company
Location: "Liuhua 11-1" China

Scope of Work: Oceaneering Intervention Engineering was responsible for the conceptual design and engineering of the modular manifold and jumper connection technology for tying in wells for the Liuhua 11-1 subsea production system deployed in 1,000-ft water offshore China in 1995-96. During the manufacturing and installation phases, OIE built the long and short jumper spools and other specialized subsea hardware items and provided installation support as a subcontractor to the principal subsea system contractor.

Client: Hardy Oil & Gas (now Mariner Energy)
Location: "Mustique" Garden Banks 240 & "Shasta" Green Canyon136 Gulf of Mexico

Scope of Work: Oceaneering provided engineering design and project management services in support of the installation of a single subsea satellite well on the Mustique prospect and two subsea satellites on the Shasta project. Oceaneering also provided the control umbilical, subsea hardware, and underwater services in support of flowline and umbilical installation. Water depth at the locations is about 800 ft. During the summer of 1995, Oceaneering installed the 11-mile long Shasta umbilical in a three-day period, followed by similar umbilical installations for Mustique. Following installation of the flowlines, Oceaneering tied in the umbilicals and flowlines using our WASP ADS technology.

Client: Kerr McGee Oil & Gas Corporation
Location: Ewing Bank 989 Gulf of Mexico

Scope of Work: Oceaneering provided engineering support for installation of two subsea satellite wells in 700-ft water depth. Other Oceaneering divisions provided underwater survey services, the control umbilical, subsea control system junction plates and a leased installation/workover control system.

Client: Shell Offshore
Location: "Tahoe" Viosca Knoll 783 Gulf of Mexico

Scope of Work: Oceaneering provided project management services for the engineering, procurement and installation of a subsea satellite completion in 1,500-ft water depth. The project was Shell's first deepwater subsea completion. Oceaneering was responsible for four of the seven CTR workscopes that Shell had defined for the project. A refurbished Placid GC 29 tree was used, along with an electrohydraulic control system and 12-mile flowline. The well was brought onstream in January 1994, after which Oceaneering assisted Shell with preparation of project documentation, including production of a video-taped record.

Client: Deepwater Production Systems, Inc. (a Tatham company)
Location: "Seattle Slew" Ewing Bank 914 Gulf of Mexico

Scope of Work: Oceaneering provided project management for the engineering, procurement and installation of a subsea satellite completion in 1,000-ft water depth. The workscope covered the entire project from design through installation of the downhole completion, subsea tree, control system, umbilical, flowline system and platform modifications. A refurbished tree originally built for Placid's GC 29 project was used, along with a piloted hydraulic control system and dual seven-mile flowlines. The well came onstream in August 1993.