By OGJ editors
HOUSTON, June 26 -- Roc Oil Co. Ltd. and partners were to begin the appraisal phase of the Wei-6-12S-1 exploration well on Block 22/12 in 30 m of water in the Beibu Gulf off China.
On test, the well, drilled to 2,535 m TD, flowed at a combined, stabilized 5,750 b/d of oil from three separate hydrocarbon columns.
Roc Oil operates the well with a 40% interest on behalf of Block 22/12 Joint Venture that includes Horizon Oil Ltd. 30%, Petsec Energy Ltd. 25%, and Oil Australia Pty. Ltd. 5%.
The joint venture is to begin drilling a sidetrack, slated to be completed in late June, primarily to obtain core data from the oil reservoirs. After which, it expects to drill a second sidetrack to intersect the various reservoir sands downdip of the discovery well 3 km away.
This sidetrack also will test the possible downdip development of a small sand section intersected in the lower part of the upper sand package in the discovery well that was not production tested but had oil recovered during wireline sampling.
Roc Oil said that the Wei-6-12S-1 well tests were designed to provide the maximum amount of technical data for possible field development rather than for maximum flow rates.
The first test in the lower sand package perforated 12 m between 2,435.5 m and 2,447.7 m of the 111 m gross column (35 m net pay) and flowed 35º gravity oil at a stabilized 1,725 b/d through choke sizes as large as 32/64-in. Preliminary pressure analysis confirmed no water contact in the well and that the oil-water contact may be more than 20 m down dip from base of the oil column.
The second test of the middle sand package was to obtain productivity data from the 65 m gross oil column (31 m net pay) encountered. It perforated a total of 28 m over two zones, 2,228.5-2,241.5 m and 2,201-16 m. The column produced flow at stabilized rates as high as 2,575 b/d of 39º gravity oil through choke sizes as large as 48/64-in., with no associated water production. The test results indicate that the reservoir has good natural productivity, Roc Oil said.
The third test of the upper sands was to provide productivity data from the lower part of the 71 m gross oil column (14.5 m net pay) and to determine the extent of the downdip of the oil-bearing reservoir. This test perforated 16 m between 2,054 m and 2,070 m and flowed at stabilized rates as high as 1,450 b/d of 38º gravity oil, through choke sizes as large as 44/64-in.
The test results indicate a reasonably productive reservoir, Roc Oil said, and the pressure gradient information suggests that the oil column extends downdip from the discovery well.