6507/6-1

General

Well 6507/6-1 was drilled close to the highest point of the main structure in the block. The prospect is defined at the Late Kimmerian Unconformity along the crest of the NNE-SSW striking Nordland Ridge. The primary objective of the well was to test the hydrocarbon potential and reservoir quality in the main structure. In addition the well was expected to obtain stratigraphic information of a complete Triassic sequence.

The prognosed depth was 4030 m.

Operations and results

Wildcat well 6507/6-1 was spudded with Wi1h. Wi1helmsen Offshore Services semi-submersible installation Treasure Saga 15 June 1986 and drilled to TD at 4040 m in Early Triassic rocks. The well was drilled with spud mud to 584 m, with gel mud from 584 m to 975 m, with Gypsum/Polymer mud from 975 m to 1611 m, with NaCl saturated mud from 1611 m to 3165 m, and with a gel mud again from 3165 m to TD. Drilling proceeded without significant problems.

The larger part of Tertiary, the whole Cretaceous sequence, and most of the Jurassic was missing in the well. Late Pliocene sediments were found to rest directly on Early Jurassic sediments. The top of the reservoir (Åre Formation) came in at 1018 m. It contained 7 m of methane bearing sandstone. The gas water contact was estimated at 1030 m. The Triassic grey beds came in at 1376 m. Apart from a weak cut fluorescence at 1032 m on a core from the Åre Formation no show was recorded throughout the well. Two cores were cut in the interval 1023 m to 1056 m in the Åre fm. and two cores were cut further down in the intervals 3041 m to 3045.2 m (Middle to Early Triassic) and 3995 m to 4013.2 m (Early Triassic). A FMT segregated sample was taken at 1028 m. It contained no oil, only gas close to 99% methane with traces of other constituent gasses including heavier hydrocarbon gases. A total of 265 sidewall cores were recovered, of which 213 were taken in Triassic rocks.

The well was plugged and abando