25/10-8 A

General

Well 25/10-8 was drilled with "Deep Sea Trym" to test the Hanz prospect with multiple targets. The well found gas and oil in the Upper Jurassic. A sidetrack, 25/10-8 A, was drilled to test the extension of this discovery to the east.

Operations and results

Exploration well 25/10-8 was spudded with the semi-submersible installation "Deepsea Trym" 17 February 1997 and drilled to a total depth of 2653 m in the Early Permian Rotliegend Group. Water based mud was used down to 1080 m and an AncoVert oil based mud from 1080 to TD. Well 25/10-8 found the Heimdal Fm to be water wet, the Upper Jurassic sands to contain gas and oil and the Middle Jurassic and Rotliegendes sands to be water wet. A core was cut from 2080 - 2107 m in the Heimdal Formation, a second core was cut from 2518 - 2546 m in Callovian Jurassic to Triassic sediments. After testing the well was plugged back to the 13 3/8" casing on 4 April 1997 as an oil and gas discovery. Sidetrack 25/10-8 A was kicked off from 1067 m and drilled to a total depth of 3460 m (2537 m TVD RKB) in Late Jurassic. An 8 1/2" hole was drilled to core point at 3110 m using oil based mud. Three cores were cut in the Late Jurassic; 3110 to 3147 m, 3147 to 3165 m , and 3165 to 3202 m. No wireline logs were run in well 25/10-8 A, only MWD. No fluid samples were taken. All reservoir sands were found water wet and sidetrack 25/10-8 A was permanently abandoned as a dry well on 27 April 1997.

Testing

Well 25/10-8 was perforated from 2391.4 - 2398.4 m in the Upper Jurassic. The drill stem test flowed 692 Sm3/D oil of density 0.84 g/cm3. No drillstem test was performed in 25/10-8 A.