31/7-3 S

Well 31/7-3 S was drilled as an appraisal well on the 31/7-1 Brasse discovery on the Bjørgvin Arch in the North Sea. The objective was to establish the extension of producible hydrocarbons within the Sognefjord formation in

the north-eastern part of the Brasse discovery.

Operations and results

Appraisal well 31/7-3 S was spudded with the semi-submersible installation Transocean Arctic on 20 November 2018 and drilled to TD at 2705 m in the Middle Jurassic Fensfjord Formation. Operations proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 2498 m and with Innovert oil-based mud from 2498 m to TD.

The well was found to be water-wet and no fluid contacts were seen in the well. XPT pressure measurements showed that the pressure in the reservoir was about 20 bar below hydrostatic and approximately 2 bar less than the pressure measured in 31/7-2 S and 31/7-2 A. This proves good lateral and vertical communication within the reservoir phases. The main cause of the depleted pressure is believed to be production from the Troll East gas-field. The only oil show in the well was on a core chip at 2582 m: Strong hydrocarbon odour, dark brown/purple direct fluorescence, no cut or residual fluorescence, no natural light residual ring.

A 54 m core was cut from 2564.6 to 2619.98 m with 100% recovery, capturing the lower half of Draupne and most of the Sognefjord Formation. No fluid sample was taken.

The well was permanently abandoned on 16 December 2018 as a dry well.

Testing

No dr