7220/5-1

General

Well 7220/5-1 was drilled to appraise the 7220/8-1 Skrugard Discovery in the Bjarmøyrenna Fault complex west of the Loppa High in the Barents Sea. The Skrugard structure is divided into three segments by erosion features, making saddle points that separate the three gas-oil contacts. The discovery well 7220/8-1 is located in the southern segment, while the appraisal well 7220/5-1 is located in the middle segment. The appraisal well is located approximately 3 km to the North of the Skrugard discovery well. The main objectives of well 7220/5-1were to prove gas and oil volumes in the Skrugard middle segment and communication between the middle and southern segments. This implied proving the exact depths of the gas-oil-contact and oil-water-contact and collecting fluid sampling from the reservoir. Another objective was to perform an extended leak-off test or similar in the cap seal and in the reservoir and to core and analyse the cap seal and reservoir.

Operations and results

Prior to the main bore a 9 5/8" pilot hole (7220/5-U-1) was drilled down to 875 m MD RT to check for shallow gas. This was approximately the setting depth of the 9 5/8" casing. No shallow gas was observed. Appraisal well 7220/5-1 was spudded with the semi-submersible installation Transocean Barents on 27 January 2012 and drilled to TD at 1740 m in the Late Triassic Fruholmen Formation. No significant problem was encountered in the operations. The well was drilled with seawater and hi-vis pills down to 898 m and with KCl/Polymer/Glycol mud from 898 m to TD.

The well penetrated Tertiary and Cretaceous Claystones and Sandstones, as well as Late Jurassic Claystones above the Reservoir. Top reservoir, Stø Formation sandstone, was encountered at 1337 m