7219/9-1

General

Well 7219/9-1 is located in the Bjørnøya Sør area between the Veslemøy High and the Polheim Sub-platform. The main target in the well was the reservoir and hydrocarbon potential of Early-Middle Jurassic sandstones. Late Triassic sandstone of the Snadd Formation was a secondary target. The wildcat well should also provide good seismic tie and gain velocity information to enable more detailed mapping of the area. It should further provide maximum amounts of information on source, seal and reservoir intervals. The well was positioned to leave a minimum of untested reserves up-dip with respect to the primary objective.

Operations and results

Wildcat well 7219/9-1 was spudded with the semi-submersible installation Polar Pioneer on 17 November 1987 and drilled to TD at 4300 m in the Triassic Snadd Formation. The hole was drilled without riser to the 20" casing depth. It was drilled to 1625 m without problems when loss of drilling mud occurred. The hole was stabilised, logged, sidewall cores were cut, and it was cemented. During cementing there were problems in the top hole with the BOP and permanent guide base. Upper part of the 30" section was cemented. Coring equipment did not get past dog leg at 2208 m. Attempts to open the hole were made but the equipment got stuck. Fishing was unsuccessful. A cement plug was set from 2185 m to 2004 m, and the hole was sidetracked at ca 2078 m. Further drilling to TD went without significant problems. The well was drilled with seawater and hi-vis pills down to 718 m and with KCl / polymer mud from 718 m to 2723 m. From 2723 m the KCl was allowed to deplete naturally and the well was drilled with a polymer mud to TD.

Top reservoir, Stø Formation, was encountered from 1950.5 m to 2062 m with 99 m net sand of 17.8% average porosity. Nordmela Formation was penetrated from 2062 m to 2205.5 m with 59.5 m net sand with 16.5 % average porosity. The Tubåen Formation from 2205.5 m to 2305 m