25/4-2

General

Well 25/4-2 was drilled ca 6 km ENE of the 25/4-1 Heimdal Discovery well, which encountered 106 m gas-bearing sands gas in the Paleocene Heimdal Formation and several thin sands with gas and oil in the Jurassic and late Triassic. The aim of well 25/4-2 was to explore the Heimdal sand section on a separate closure.

Operations and results

Wildcat well 25/4-2 was spudded with the semi-submersible installation Neptune 7 on 18 October 1973 and drilled to TD at 2775 m in the Late Cretaceous Jorsalfare Formation.

The well penetrated a 405 m thick section with Heimdal Formation sands from 2156.5 m to 2561 m. The reservoir characteristics were quite the same as in well 25/4-1: clean sands with occurrence of only small shale-sand laminae and a few carbonaceous stringers. A nine-meter thick oil column was found from top of the reservoir down to an OWC at 2165.5 m, which was estimated to be 8.5 m higher than in 25/4-1. Other reservoirs were water-wet except a very thin bed of calcareous sand between 2591 and 2597 m (Våle Formation) with some residual oil according to the log interpretation, and where a small methane kick occurred.

One conventional core was cut in the interval 2159 m to 2172 m. Only 2166.6 m to 2167.4 m was recovered. Good shows with bleeding oil was observed on the recovered piece of core. Three Formation Interval Tester samples were taken. FIT 1 and 3 were taken at 2162.5 m. The FIT 1 fluid was transferred under bottom hole pressure for PVT studies. FIT 3 recovered 4.15 1itre of oil, 5.75 litre of filtrate + mud and 136 litre of gas. FIT 2 at 2165.8 m produced 9.9 1itre of water, filtrate, and mud with some traces of oil.

The well was permanently abandoned on 6 December 1973 and has been classified as a minor oil discovery.

Testing

No drill stem test was performed in the well.