GULF OF MEXICO
Michael Crowden Houston
BAHA prospect pushes deepwater drilling to new depth
A group led by Shell Oil is drilling a wildcat well in a world record water depth of 7,625 ft. Designated BAHA, the prospect is located about 200 miles southeast of Corpus Christi, Texas. The group includes operator Shell, Amoco Production, Mobil Exploration & Production US, and Texaco Exploration & Production. Located in the Alaminos Canyon area, the BAHA prospect lies beneath water depths of 6,500 to nearly 9,000 ft. The partners, who had adjoining leases, agreed to cross-assign their interests on a 25% equity basis. The name BAHA resulted from the first initial of each partner's prospect name for its lease-Shell's Brachiosaurus, Amoco's Anaconda, Mobil's HI-C, and Texaco's Alpha Centauri. The partnership has chartered the Sonat drillshipDiscoverer 534 to drill the well. The drillship went into drydock at Mobile, Alabama for an upgrade necessary to drill in ultra-deepwaters. Drilling began in late March and was expected to continue for about four months.
Texaco puts its Petronius prospect on a fast track
Texaco says its Petronius deepwater prospect has been confirmed commercial by a third delineation well drilled as part of an appraisal program. A development program is planned. Estimated reserves are in the range of 80 million to 100 million bbl of oil equivalent.
Texaco, operator, and Marathon Oil each own 50% working interest in the prospect. The partners have formed an inter-disciplinary, inter-company project team to facilitate development and initial production of Petronius-a process expected to take two years. Initial production is expected in late 1998 or early 1999. The Texaco/Marathon team has already completed initial screening of development concepts and contracts for preliminary design work are expected to be awarded during the next few weeks. Selection of the final development concept is anticipated this summer. The three delineation wells drilled in addition to the initial discovery well "successfully scoped out" the extent of the reservoirs in Viosca Knoll 786, said Dr Bruce S Appelbaum, manager of TEPI's offshore division in New Orleans. The Petronius discovery well, completed in August 1995, tested a daily rate of 7,700 b/d of oil and 4.4 million cu ft/day of gas. Since then, Texaco has drilled three delineation wells: (1) The Viosca Knoll 786-2 well was directionally drilled to 11,554 ft measured depth with a bottom-hole location 0.6 miles northeast of the discovery well. (2) A down-dip sidetrack of the second well was drilled to 14,500 ft measured depth with a bottom-hole location 1.1 miles southwest of the discovery. (3) The third well was directionally drilled to 16,695 ft measured depth with a bottom-hole location two miles southwest of the discovery well.
Three of the four wells on the prospect have been temporarily abandoned and will be re-entered and completed early in the development phase of the project. This will allow production to occur while the remainder of the development program is underway. The Petronius prospect is located in 1,750 ft of water.
Seneca Resources maintains a steady pace in drilling
National Fuel Gas says its exploration and production subsidiary, Seneca Resources, is maintaining an active pace in the Gulf of Mexico. Seneca recently drilled and tested two wells at Vermilion 252. The wells are producing at combined rates of 3,000 b/d of oil and 1.4 million cu ft/day of gas from two separate zones. (1) Well OCS-G-5431 A-1 has been dually completed. The upper zone tested 820 b/d of oil and 431,000 cu ft/day of gas with 1,080 psi flowing tubing pressure on a 16/64-inch choke. The lower zone flowed 768 b/d of oil and 404,000 cu ft of gas with 1,140 psi flowing tubing pressure. No water was produced from either zone. (2) Well OCS-G-5431 A-2 also was dually completed. The upper zone tested 1,050 b/d of oil and 326,000 cu ft of gas. Flowing tubing pressure was 1,150 psi on a 14/64-inch choke. No water was produced. The lower zone flowed 618 b/d of oil, 203,000 cu ft/day of gas, and six b/d of water. The lower zone had 1,425 psi flowing tubing pressure on a 14/64-inch choke.
Seneca operates a portion of the block and the A platform. Two additional development wells are being drilled on a farm-out basis. These are expected to go into production in April. Chevron is the leaseholder.
Shell awards Mensa contract to Stolt Comex
Shell Offshore has awarded a $6 million contract for the installation of well control/chemical injection umbilicals on the Mensa Field to Stolt Comex Seaway. SCS says the project will set two new records for the offshore industry: (1) the umbilicals will be installed at a record depth of 1,625 meters; and (2) at 100 km in length, the umbilicals will be the longest in the world. Installation will be carried out bySeaway Condor in early 1997. Altogether more than 250 km will be laid to connect three subsea wells to a manifold, and the manifold to the field platform.
While in the Gulf,Seaway Condor will also carry out jobs for Agip and Mobil. The other contract won by the company's Houston office, which was set up last June, was platform and pipeline repair work for Pemex in the wake of Hurricane Roxanne. This was performed by Seaway Pelican.
Poseidon Pipeline launched by Texaco Leviathan Partners
Texaco and Leviathan Gas Pipeline Partners have formed Poseidon Oil Pipeline, a 50/50 joint venture company. The new company will construct, own, and operate the Poseidon pipeline, the first phase of which become available for use in March. The pipeline, operated by Texaco, is located in the central Gulf of Mexico and connects with Texaco's onshore pipeline system at Houma, Louisiana. Leviathan began the construction of the pipeline in August 1995. Initially, the pipeline will extend from Garden Banks 72 for approximately 117 miles along the edge of the Outer Continental Shelf to Leviathan's platform at Ship Shoal 332. From there, it extends to shore at Caillou Island, Louisiana. Ultimately, Poseidon will consist of approximately 200 miles of 16- to 24-inch diameter pipeline capable of delivering up to 400,000 b/d of sour crude oil production to market outlets in Louisiana.
Bellwether, Samedan drill discoveries offshore Texas
Bellwether Exploration reports it has completed the third of a five-well workover program in the Cove Field, off Matagorda Island. The SL 57686-11 tested 1.1 million cu ft/day of gas on an 8/64-inch choke with a flowing tubing pressure of 2,600 psi. Since beginning in January, the workover program has boosted production 26%. The program ends in April.
Separately, Samedan scored a natural gas discovery at High Island A-549. The well logged approximately 200 ft of pay in multiple zones. The majority of the logged pay is natural gas, but at least three zones appear to contain oil or condensate, said partner Forest Oil.
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