30/10-1

General

Well 30/10-1 is located on the Northern apex of the Frigg field. The well was drilled as a wildcat, primarily to evaluate the Lower Eocene sand ("Frigg Field Clastic Tongue") in the area. Secondly, the well should evaluate the Paleocene sands and the Late Cretaceous limestone. The plan was to set the 9 5/8 inch casing in the top of a high-pressure zone (Cretaceous Shale) prior to moving the rig Saipem Due to another location. The hole should then be re-entered with another rig and drill deeper to evaluate a deep-seated structural closure.

Operations and results

Well 30/10-1 was spudded with the vessel Saipem Due on 5 May 1973 and drilled to TD at 2917 m in Late Cretaceous (Maastrichtian) shale. Initial drilling from the sea floor to 1067 m was with seawater and gel. Below 1067 m a fresh water Spersene XP 20 (lignosulphonate) mud system was used.

The thickness of the pay section of the Frigg Clastic Tongue (Primary objective) was disappointing in that it was very thin. A green shale unit replaced the expected pay section. Formation interval test and logs indicate that approximately 4 m of the Frigg Clastic sand contained gas and approximately 6 m could possibly be oil bearing. No other good hydrocarbon shows were encountered below the Frigg Clastic Tongue. in the rogaland Group almost 200 m of sand were present, however, the sand was void of hydrocarbons, with the exception of some scattered fluorescence in the upper portion. Five cores were cut in the Frigg sand in the interval 1974 m to 2010 m. No sidewall cores were taken. Four Formation Interval Tests (FITs) were taken in the Frigg sand. FIT No 1 at 1960.5 m recovered, 29 cubic feet of gas, 5 litres water and 0.5 litres mud. FIT No. 2 at 1989.5 m recovered 10 litres water. FIT No. 3 at 1974.5 m recovered 7 litres liquid (mud and water) and 100 cc oil. FIT No. 4 at 1966 m recovered 6.5 cubic feet gas, 2.25 litres oil, 300 cc mud, and 4.75 litres of water. Oil g