6407/6-1

General

Well 6407/6-1 was the third well to be drilled on the TrØndelag Platform offshore Mid Norway. The primary objective of the well was to investigate the reservoir potential of Middle Jurassic Sandstones (Fangst Group). Secondary objectives of the well were the Early Jurassic Sandstone Hl-2 (Tilje and Åre Formations), and sandstones in the Triassic.

Operations and results

Wildcat well 6407/6-1 was spudded with the semi-submersible installation Zapata Ugland on 16 September 1984 and drilled to TD at 2895, 47 m into the Triassic Red Beds. In the 12 1/4" hole section the hole suddenly packed off at 1591, probably due to overpressured Early Eocene clays. The pipe was worked free and the mud weight increased. After that drilling proceeded without further difficulties. Logs were not run below 2869 m. The well was drilled with seawater/hi-vis slugs/gel down to 456 m, with gypsum/lignosulphonate mud from 456 m to TD. The well proved a good "upper sandstone member" (Garn Formation), and a "lower sandstone member" (Ile Formation). Sandstone sequences interbedded with siltstone, claystone, and coals were encountered also in the interval 2244 m to 2457 m, the Tilje Formation. Isolated weak shows were recorded on core no 1 in the lower part of the Garn Formation, otherwise no shows were observed in any part of the well. The RFT tool was run in the Middle Jurassic and four pressure points were obtained in good to very good permability sandstone in the Garn Formation. The average gradient was 1.00 g/cm, indicating the formation was water bearing. The electrical logs proved all reservoir sections in the well to be water bearing.

Four cores were cut in the Middle Jurassic Sandstone over the interval from 1870 - 1888.2 m. No fluid samples were taken.

The well was permanently abandoned on 26 October 1984 as a dry well.

Testing

No drill stem test was performed.