PORT STANLEY -- Desire Petroleum has classified its first well in the North Falkland basin as a gas discovery. The Liz well 14/19-1 reached a T/D of 3,667 m (12,031 ft), and is currently being plugged and abandoned.
Initial log interpretation suggests that the well encountered 17 m (56 ft) of net hydrocarbon pay at sub-surface depths between 2,961 and 3,031 m (9,714 and 9,944 ft) within a zone of over-pressured, and chiefly sandstone, reservoir. A hydrocarbon sample and formation pressures were recovered from this interval.
Early analysis indicates wet gas, with no apparent water-leg in this interval. Desire adds that further work will be needed to evaluate reservoir quality, to determine the trapping mechanism, and to assess the discovery’s potential.
The well also recovered dry gas in a separate accumulation in a different pressure regime from a deeper interval below 3,400 m (11,155 ft). This suggests that gas pay is present in generally poor quality reservoir. However, there is uncertainty over the rock type and its reservoir potential.
The Liz fan was encountered between 2,540 and 2,568 m (8,333 and 8,425 ft). Desire says that good oil shows were recorded while drilling, but logging and sampling confirmed that this reservoir interval was tight. The company believes the Beth fan was also penetrated between 2,654 and 2,672 m (8,707 and 8,766 ft), again with oil shows in tight reservoir. Further weak oil shows were recorded in conglomeratic zones between 2,706 and 2,932 m (8,878 and 9,619 ft).
The well was not suspended for later testing, as it had not been designed to test over-pressured gas. And due to increasing overpressure concerns the well did not reach the deepest play type in the pre-rift.
Liz was the first in a multi-well, multi-operator campaign offshore the Falkland Islands using the semisub Ocean Guardian. Rockhopper will now drill two wells in the North Falkland basin and BHP one in the East Falkland basin before the rig returns to Desire for further drilling later in the year.
Desire says it will use the next three months to evaluate data from the Liz well. These and the results of the Rockhopper wells should assist planning of future well locations. Desire's Chairman Stephen Phipps says:
"This well has proved complex and highly encouraging. Hydrocarbons have been found in two separate intervals, the geological model for the basin has been confirmed and at least two petroleum systems have been drilled, with hydrocarbon shows recorded over a wide interval. More sandstone was encountered than expected but typically of poor quality. However new reservoir targets have been identified and the challenge will be to predict where these may occur in better quality.”