2/7-16

General

Wildcat well 2/7-16 was drilled on a structure on a broad terrace to the south of Edda field and with a geological environment similar to Edda. The primary objective was to test the potential for hydrocarbon production from Danian and Late Cretaceous Limestones on a low relief structural closure. Secondary objective was a possible stratigraphic trap potential in Early Cretaceous sandstones.

Operations and results

Well 2/7-16 was spudded with the semi-submersible installation Nortrym on 20 March 1980 and drilled to TD at 4818 m in the Early Cretaceous Ågard Formation. The well was drilled with Seawater/Native Solids mud down to the 13 3/8" casing point at 1523 m, with Seawater/Lignosulphonate from 1523 m to the 9 5/8" casing point at 3794 m, and with Calcium chloride/Sodium chloride XC polymer mud from 3794 m to TD.

Hydrocarbon shows were encountered in the Danian and Upper Cretaceous limestone. The porosity was poorly developed and testing verified the zones to be non-productive. Early Cretaceous had shows in limestones, claystones, shales, and marls, but no sandstones were found.

Thirteen conventional cores were cut continuously from 3182 m to 3402 m in the Ekofisk and Tor Formations Formations. Twenty-five RFT measurements were attempted in the gross interval 3823.8 - 4783.6 m. A fluid sample was obtained at 4587.9 m. It contained 50 ml formation water and 39 cubic feet (1.1 Sm3) gas.

The well was permanently abandoned on 12 July 1980 as a dry well with shows.

Testing

Two drill stem tests were conducted. DST 1 at 3279.7 to 3288.8 m in the Tor Formation produced 660 barrels (105 m3) of water /day, with traces of oil and gas. DST 2 from the intervals 3193.1 - 3199.8 and 3201.4 - 3215.4 m in the Ekofisk Formation produced 28.8 barrels (4.6 m3) water /day with no oil or gas before acid treatment. Well died completely after acid, with only a very weak flow of acid gas.