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Exxon’s 16th plan of development for Point Thomson gets state approval Commerciality of eastern North Slope unit is linked to developing both Brookian and Thomson oil rims, and Thomson gas Kay Cashman PNA Editor-in-Chief
On Oct. 8, state Division of Oil and Gas Director Ken Boyd told PNA that he has approved the 16th plan of development for the Point Thomson unit, which lays out everything expected of the unit operator and owners through Sept. 30, 2000. (See related story on page 1 of this issue.)
As the result of the information gathered in previous plans, Boyd said, the owners of the eastern North Slope unit, which lies on the western border of the Arctic National Wildlife Refuge, “are now discussing things like what kind of facilities will be needed, what kind of pipeline size, can you use Badami ... Their discussions ... go beyond geology and help answer questions that need to be answered on the way to commercializing the unit,” he said.
“The next step is facilities design,” Boyd said: “What is needed to bring this field into production?”
Commerciality linked to gas cycling “Brookian and Thomson oil rim developments are linked to the commerciality of a Thomson gas cycling project,” unit operator Exxon Company USA said in the 16th plan.
Results of “facilities optimization, reservoir and drilling studies” done during the recently completed 15th plan have “encouraged the owners that a gas cycling project may be viable at Point Thomson if further studies and technology advancements result in cost reductions and reduced reservoir and geological uncertainty,” said Exxon.
Recent advances in the technology of extended reach drilling, high rate/high pressure compression and 3-D seismic have contributed to improved outlook for Point Thomson, the operator said.
Eight producing gas wells in development scenario The owners’ current development scenario for a Thomson gas cycling project involves drilling eight gas producing wells from two onshore drill sites to produce an estimated 1 billion cubic feet of wet gas per day. Fifty to 70 thousand barrels per day of condensate would be separated from the gas for export to pump station No. 1.
Gas would also be compressed and re-injected into the Thomson gas cap through seven injection wells from one centrally located onshore drill site.
In-field infrastructure would include gathering, injection and fuel gas pipelines, construction and operating camps, dock, airstrip, and power generation.
This scenario does not include a road to Prudhoe Bay.
One of the major uncertainties affecting the economic outlook of the gas cycling project is the estimate of condensate yield over the life of the project.
Thomson oil rim studies disappointing Boyd said everything he’s seen on Point Thomson points to a need to develop both the gas and the overlying oil horizons.
Exxon said the owners are continuing to conduct simulation studies of the Thomson oil rim: “Predicted performance was disappointing, suggesting that oil recovery would likely be insufficient to payout the cost of dedicated oil rim wells.” Future studies will “focus on determining if the gas cycling project can be modified to allow some gas cycling through the oil rim to target this resource in a cost-effective manner.”
One concern identified by the owners was the presence of “heavy oil or tar dispersed throughout” the Thomson oil rim accumulation. The presence of tar, said Exxon in its review, could “potentially reduce the outlook for recovery.”
Brookian accumulations better defined Much of the geoscience effort during the last year was directed at better defining the five Brookian oil accumulation areas, including well performance and producibility.
The Sourdough wells are in the shallower Brookian — so-called turbidite — accumulations, said Boyd. BP Exploration (Alaska) Inc. and Chevron USA drilled the Sourdough prospect in the southeast corner of Point Thomson; over the last year all unit owners have become interest owners in Sourdough and are looking at a stand-alone facility for developing Sourdough and other Brookian areas within the unit. Studies will also look at integrating Brookian development with the Thomson gas cycling project.
Specifics of the 16th plan In addition to seismic reprocessing, gas cap tests and studies, evaluation of additional appraisal drilling, environmental surveys and studies, and refining the Thomson reservoir model, the 16th plan calls for work on surface and subsurface optimization and cost reduction. This will all be necessary for the 17th plan of development, which is to include selection of a base development plan, as well as a proposal to refine appropriate unit boundaries for Point Thomson.
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