30/9-15

General

Well 30/9-15 is located in the Eastern part of Block 30/9 on the Oseberg Sør Field. The primary objectives of the well were to test the hydrocarbon potential of the Brent Group, Cook, and the Statfjord Formations on the J-north compartment with respect to commercial volumes and future relinquishment decisions. It was not possible to locate a vertical well on the J-north compartment which could test all three reservoir levels in an optimal position. Priority was therefore given to the Brent reservoir, and the well location was chosen in order to prove hydrocarbons in the Brent Group, leaving a minimum of untested hydrocarbon potential in the lower Ness reservoir up dip of the well. Secondary objectives were to penetrate the Cook and Statfjord Formations shallower than the water up to (WUT) top Statfjord in well 30/9-5 (2564 m MSL).

Operations and results

Wildcat well 30/9-15 was spudded with the semisubmersible installation "West Vanguard" on 7 December 1993 and was drilled to a& total depth of 2764 m in the Early Jurassic Statfjord Formation. The well was drilled with sea water and hi-vis pills down to top of 12 1/4" section at 936 m, and with ANCO 2000 mud with glycols from 936 to TD. The Brent Group was encountered at 2249 m and was proven to be oil bearing in the lower Ness Formation, with an ODT at 2348.5 m. The ORE (Oseberg/Rannoch/Etive) Formations contained residual oil. The Cook Formation was proven water bearing though moderate to weak shows were recorded from sidewall cores taken over the interval 2465.5 - 2475.5 m. The Statfjord Formation was proven water bearing. Three conventional cores were recovered from the intervals 2240 m to 2250 m (Hardråde, Åsgard, and Ness Formations), 2256m to 2281 m (Ness, ORE, and Drake Formations), and 2283 m to 2306 m (Drake Formation). A wire line MDT sample of acceptable quality was recovered from 2249.9 m in the oil zone in the Ness Formation. The well was plugged back and permanently aba