30/9-8 R

General

Well 30/9-8 R was drilled on the Oseberg Omega structure, which is located between the Gamma structure to the east and the B structure to the west, and extends northwards into 079 license area. The main target of the well was sandstones in the Middle Jurassic Brent Group. The primary objectives were to prove the extension of the Omega oil column into license 104, find the fluid contacts, and test communication and reservoir relationship with the Omega North and B prospects. The well was planned to drill approximately 50 m into the Dunlin Group at a final depth of ca 3182 m RKB. Well 30/9-8 R is a re-entry of well 30/9-8, which was suspended at 1060 m while the rig left location temporary for another contract.

Operations and results

Wildcat well 30/9-8 was re-entered (30/9-8 R) by the semi-submersible rig Polar Pioneer on 15 August 1989. Cement and float collar was drilled from 1007 to 1060 m in 30/9-8. Well 30/9-8 R was then drilled to TD at 3200 m in the Early Jurassic Drake Formation. Drilling proceeded without significant problems. There was no indication of shallow gas. The well was drilled with a KCl/PAC/Polymer mud from 1060 m to TD.

Top reservoir came in at 2814 m, approximately 30 m deeper than prognosed. The reservoir was oil bearing from 2824.5 to 2851 m. Below 2851 m the water saturation gradually increased. RFT data indicated a free water level at 2856 m (2832.5 m MSL). However, the available data do not permit the exact definition of the oil water contact, which is in the range 2856 -2862.5 m. The net pay was determined to be 22 m with average water saturation calculated to 46%. Average porosity was 18.5%. RFT results showed no pressure communication with well 30/9-4 within the Tarbert Formation. Well 30/9-8 is