ID: 108
OBJECTID: 108
wlbNpdidWellbore: 110
wlbName: 30/6-15
wlbHistory:

General

Well 30/6-15 was drilled on the Gamma North structure west of the Oseberg Alpha structure. Gamma North is a NNW-SSE trending fault block down-faulted to the adjacent Alpha structure. The primary objective was to find hydrocarbon accumulations in the Statfjord Group. The secondary objective was to test the hydrocarbon potential in the Cook Formation. The total depth of the well was planned ca 270 m into the Triassic at a depth of ca 3950 m, corresponding to ca 3200 m TVD.

Operations and results

Wildcat well 30/6-15was spudded with the semi-submersible installation Treasure Seeker on 2 May 1984 and drilled deviated to TD at 3972 m (3200 m TVD) at a position ca 2180 meters west of the surface position. Operations suffered from comparatively much down time due to hole problems and equipment repairs. The 8 3/8" and 6" sections in particular suffered hole problems and difficult logging. The well was drilled with spud mud down to 195 m, with gel/sea water from 195 m to 617 m, with SafeMul oil based mud from 617 m to 3005 m, and with NaCl/polymer mud from 3005 m to TD.

The Etive Formation (2884 - 2902 m, 2358 - 2372 m TVD) truncated by Cretaceous strata was found water bearing.

No Cook Formation reservoir was encountered. The Statfjord Formation (3241 - 3548 m, 2641.5 -2878.5 m TVD) sandstones were found gas bearing down to 3313 m (2697 m TVD), and oil bearing down to 3348 m (2723.5 m TVD). An oil/water transition zone is seen down to 3359 m MD (2732 m TVD). The lithology of the hydrocarbon bearing interval was predominantly sandstones with some interbeds of claystones/shales. Net pay in the gas zone was calculated on logs to 67.4 m giving a net to gross ratio of 0.94. Ne
wlbHistoryDateUpdated: 2016-05-19T00:00:00