Source: Desire Petroleum
The Liz well 14/19-1, drilled by Desire Petroleum plc, in the North Falkland Basin, has reached a total depth of 3,667 meters. Final logging has been completed and the well is now being plugged and abandoned as a gas discovery.
The initial log interpretation indicates that 17 meters of net hydrocarbon pay were encountered between 2961 and 3031 meters within a zone of over-pressured, predominantly sandstone, reservoir. A hydrocarbon sample and formation pressures were recovered from this interval. The initial analysis suggests that the hydrocarbon type is wet gas, but its precise characteristics will be confirmed through further analysis. There is no indication from log data or pressure data of a water-leg in this interval. Much work is now required to evaluate the reservoir quality, to determine the trapping mechanism and to assess the potential of this discovery.
Dry gas was also recovered from a deeper interval below 3,400 meters indicating that gas pay is present in generally poor quality reservoir but there is considerable uncertainty on the rock type and more work will be required to assess its reservoir potential. This gas is a separate accumulation from that above, in a different pressure regime. Again further work is required to assess the significance of this interval.
The Liz fan was encountered between 2,540 and 2,568 meters. Good oil shows were recorded while drilling but logging and sampling confirmed that this reservoir interval was tight. It is believed the Beth fan was also penetrated between 2,654 and 2,672 meters also with oil shows in tight reservoir. In both fans, work will now try to determine whether better quality reservoir may be developed updip.
Weak oil shows were also noted in conglomeratic zones between 2,706 and 2,932 meters.
The well was not suspended for later testing as the well was not designed to test over pressured gas.
Additionally, further technical work is required in order to understand better the reservoirs to ensure any test is designed optimally.
Due to increasing overpressure concerns the well did not reach the deepest play type in the pre-rift.
Liz was the first well in a multi-well campaign to explore the North Falkland Basin. 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 will now have at least three months to evaluate all the data from the Liz well and this together with the data from the Rockhopper wells will greatly assist in the selection of the future locations for the Desire wells.
Commenting on the announcement, Desire's Chairman Stephen Phipps said:
"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.
This well has provided some promising results, gas has been discovered at two levels and the prospectivity of the basin has been greatly enhanced. We now intend to carry out technical work to assess and analyze the information that we have obtained from this well and we are very much looking forward to resuming the drilling campaign later in the year."