January 2000 Vol. 221 No. 1  Offshore

Robert E. Snyder,  Editor

Deepwater production adding important U.S. oil supplies

The U.S. Department of the Interior’s Minerals Management Service (MMS) has published data showing that production of offshore oil and gas in the deepwater (>1,000 ft) portion of the Gulf of Mexico reached an all-time high in 1998, and it continues to escalate rapidly. Production of deepwater oil rose 279% in the five years of 1994 through 1998, and gas production rose 252%. The actual numbers are: 1994 (115 Mbopd, 436 MMcfgd); 1995 (151 Mbopd, 496 MMcfgd); 1996 (206 Mbopd, 762 MMcfgd); 1997 (296 Mbopd, 1,044 MMcfgd); and 1998 (436 Mbopd, 1,534 MMcfgd).

According to MMS Director Walt Rosenbusch, "The 1998 increase is significant and of national importance. While total U.S. production of oil declined some 410,000 bpd from 1994 through 1998, the decline would have been nearly twice as large if the deepwater production had not increased by 321,000 bpd."

From 1997 to 1998, deepwater oil production rose 47%. The production increase in 1998 was sustained by oil/gas company projects that began production in 1997 and 1998. In 1999 – as of mid-October – 11 additional projects had begun or were scheduled to begin. MMS’s website address is: www.mms.gov.

Ekofisk abandonment. As reported in Subsea Engineering News of November 4, in an article submitted by Nick Wade, Oslo, Phillips Petroleum has submitted a decommissioning and removal plan for the Ekofisk complex, with a time-span of 20 years to complete the full program. All topsides would be removed, whichever alternative is chosen for the jackets.

The article says Phillips prefers a solution costing about $1.1 billion in 1998 dollars. This would involve removing the jackets for recycling onshore and leaving in place: the concrete Ekofisk tank; 150 mi (235 km) of pipelines, all buried to at least 0.8 m; and the cuttings piles, now heavily eroded, for seven platforms. Reportedly, Phillips does not recommend the artificial reef option for the jackets.

Removing the tank would be a massive engineering and operations job that could cost more than $400 million. This would include sealing the outer protective wall to raise the structure in one piece. The article says the proposed timetable is to remove 14 steel platforms from Ekofisk in four phases, from 2003 to 2018, with topsides removed in the first three phases ending in 2015, and jackets during the final three years.

Phillips is quoted as saying that choosing the so-called "most environmentally benign" options in all phases – i.e., everything taken up and brought ashore – would add $800 million to the total cost, of which the Norwegian state will pay two-thirds. The government will reportedly choose the final solution and submit its recommendation by 2001.

Mobile Production Unit growth report. The fifth report available from the UK’s Smith Rea Energy Analysts Ltd. (SREA) since 1994 on the Mobile Production Unit (MPU) market analyzes the current market, identifies the UK’s MPU development prospects and presents a forecast of MPU activity to 2005, factoring in the impact of recent oil price fluctuations. Given the uncertainty in the long-term direction of oil prices, a number of alternative projections are provided for the main geographical areas, and for the main MPU types.

SREA says MPUs continue to be an important aspect of offshore field development. Although the previous strong growth momentum has been "checked" by recent adverse economic factors, operators are actively reviewing the oil market outlook with a view to determining the viability of MPU development in the current, high-oil-price environment.

The market is already showing signs of recovery after a year’s pause, primarily in the FPSO lease markets. Sectors with the greatest potential for growth in the medium term, the report says, are the FPSO, TLP and Spar markets. It is probable that there will be some shrinkage in the jackup (JPU) market and moderate growth in floating production system (FPS) markets. The long-term forecast in the FPS market, in particular, is showing continued growth at least to 2005.

The report discusses technological and commercial trends of the MPU market, including subsea separation, and mooring and riser technologies. It reviews economic factors affecting development decisions for implementing MPU projects and provides a database of current / committed MPUs and their production. The report, Mobile Production Units: Current status & future outlook 2000–2005, contains over 90 pages. For orders and inquiries contact: SREA; Tel. 44 1227 738844; Fax. 44 1227 738866; e-mail: sreapubs@ easynet.co.uk.

Diverless pipeline repair. Successful "on bottom" repair of two, high-pressure, 4.5-in. pipelines at a record water depth – in excess of 1,000 ft – on the Mariner Energy-operated Dulcimer field, in the Gulf of Mexico, represents another deepwater first for Oceaneering International, and it overcomes another major hurdle facing offshore operators.

Following review of the damage and potential repair scenarios, the operator chose subsea installation of the Smart Flange Plus pipeline repair system proposed by Oceaneering. This was seen as potentially the quickest, most cost-effective solution.

The damaged 4.5-in. flowlines tie back the field to its host platform on Garden Banks 236. Damage to the two flowlines and an umbilical was discovered by pressure testing prior to commissioning. A survey using ROVs revealed two neat, oval-shaped, 4-in. ´ 2-in.holes in the lines, with the umbilical damaged to its second level of protective reinforcing wire.

The repair was based on the contractor’s MSV Ocean Intervention, with moon pool, resident 150-hp Hydra Millennium ROV and DP. Oceaneering built eight adjustable pipe stands, and flowline alignment / spool-piece installation A-frames for the operation. Additional equipment included a WACH’s guillotine saw, pipe-end prep tool, pipe coating removal tool, and flange-alignment / installation system. After tank testing, work offshore commenced six days after contract award.

Both 4.5-in. flowlines were repaired in seven days using the Smart Flange Plus connectors. Fortunately, the umbilical was deemed fit for purpose. The lines were pressure tested to 7,800 psi for eight hours, indicating successful first time repair. The contractor says this installation helps extend pipeline repair technology to water depths of 10,000 ft.

Copyright © 2000 World Oil
Copyright © 2000 Gulf Publishing Company