Corallian Energy, operator in license P1918, just south of the Wytch Farm field, started drilling well 98/11a-6 in the beginning of February (“Colter well has spudded”) and has now announced that the well unexpectedly remained on the southern side of the Colter Prospect bounding fault and therefore appraised the Colter South discovery instead.
The well encountered oil and gas shows over a 9.4m interval at the top of the Sherwood Sandstone reservoir. A petrophysical evaluation of the LWD data has calculated a net pay of 3m. Similar indications of oil and gas were encountered in the 98/11-1 well, drilled in 1983 by British Gas, within the Colter South fault terrace.
Provisional analysis of the new data indicates that the two wells may share a common oil-water-contact having both intersected the down-dip margin of the Colter South prospect, Corallian explained. Corallian’s most recent assessment of the Colter South Prospect prior to drilling the 98/11a-6 well had estimated a mean recoverable volume of 15 mmbbls. Further work will be required to refine this assessment with the new well data.
Side-track to test main prospect
Preparations to side-track the 98/11a-6 well have started. The side-track will be drilled directionally to a Sherwood Sandstone target within the Colter prospect on the northern side of the bounding fault and is expected to take approximately 2 weeks to complete.