E&D PICKS UP STEAM IN BASS STRAIT

Industry's exploration and development campaign is heating again in Australia's Bass Strait.

An Australian group led by Sagasco Resources Ltd., Adelaide, is preparing an appraisal program to delineate reserves for a proposed $500 million (Australian) development project in the Bass Strait to supply Tasmania with its first natural gas.

In other Bass Strait action, a joint venture of Esso Australia Resources Ltd. and BHP Petroleum Pty. Ltd. is about to resume drilling off Victoria's southeastern coast.

TASMANIA PROJECT

The Sagasco group has been negotiating with Tasmania's government for almost 3 years over plans for commercial development of Yolla oil and gas field in the Bass Strait off the island's northern coast 135 km from Burnie.

Appraisal is expected to involve seismic surveys in addition to drilling two wells at a cost of about $40 million.

A preliminary estimate of potential reserves, based on one well drilled in the early 1980s, is 300 bcf of gas, 30 million bbl of condensate, 7.3 million bbl of natural gas liquids, and 3 million bbl of oil.

The 1 Yolla discovery well, in 262 ft of water in the Bass basin, flowed 300 b/d of 44.5 gravity paraffinic crude through a 1/4 in. choke from an interval at 6,014-16 ft, 12 MMcfd of gas and 933 b/d of condensate from an expanded interval at 5,816-6,016 ft, and 15 MMcfd and 580 b/d of condensate through a 1/8 in. choke at 9,216-9,593 ft (OGJ, Sept. 8, 1986, p. 121).

Amoco Corp. was operator of the 1985 discovery well but since has withdrawn from the project.

The Tasgas group, consisting of the Tasmanian government, Tasmanian Hydroelectric Commission, and aluminum producer Comalco, is considering using gas to fuel the Bell Bay aluminum plant as well as the state's electric power grid. Yolla also would supply, NGL and condensate to an onshore processing plant.

Further negotiations between the Sagasco group and Tasgas hinge on establishment of enough reserves in the field and cost of supplies.

Interests in Yolla, currently held under the retention license plan, are Sagasco 40%, Gas & Fuel Exploration of Victoria, Melbourne, 30.6%, Galveston Mining 14%, Cultus Petroleum NL, West Perth, 10.4%, and Petroz NL, Perth, 5%.

ESSO-BHP PROGRAM

The Esso-BHP joint venture has moved in the Atwood Falcon semisubmersible via the Soviet built Trans-Shelf heavy lift barge from Singapore to drill three exploratory wells and four delineation wells the next 12 months.

The $90 million (U.S.) rig was floated free late last month in the sheltered waters of Westernport Bay southeast of Melbourne and is stocking up for the long drilling program on Esso-BHP permits in the Gippsland basin. Day rate is $120,000/day.

The program is in line with announcements by operator Esso and BHP last year that they are considering a $650 million (Australian) project to install two platforms, Bream B and Tuna West, in Bass Strait.

Initial work calls for soil sampling in Bream oil and gas field in preparation for a decision to be made later this year about economics of installing a second production platform, Bream B, to boost oil recovery in the field. Soil tests are to help determine possible pile designs and whether the platforms ought to be concrete or steel.

In addition, the venture has begun an extensive seismic program in the Gippsland basin with the Pacific Titan seismic vessel.