By John Lee.
WesternZagros Resources has completed its testing program in the deepest of the three stacked reservoirs drilled by the Kurdamir-2 exploration well in the Kurdistan Region of Iraq.
The testing confirmed an oil discovery in low permeability fractured limestones of the Cretaceous-age, Shiranish Formation, adding to the previously announced major oil discovery in the Oligocene reservoir. The Shiranish reservoir exhibited non-commercial flow rates in this location.
The combined audited unrisked mean estimate for all three reservoirs on the Kurdamir prospect is 1,609 million barrels (“MMbbl”) of prospective oil resources as at May 31, 2012, 11 percent of which (181 MMbbls), is attributed to the Cretaceous.
The Company now expects this number for the Cretaceous to be revised downward, although it is not expected to materially change the estimate of prospective resources of the whole Kurdamir prospect.
Commenting on the Shiranish test results, WesternZagros’s Chief Executive Officer Simon Hatfield (pictured) said:
“While we had hoped that the Shiranish reservoir might duplicate the tremendous results we saw in the Oligocene, we also knew that the characteristics of the Shiranish vary a great deal by location. Although we didn’t achieve a commercial flow rate due to the tight nature of the Shiranish reservoir at Kurdamir -2, we did confirm it contains light oil.
“These test results add to the growing evidence that Kurdamir and the neighbouring Tophkana structure are in fact a giant shared structure with common oil accumulations. We look forward to the remainder of the Kurdamir-2 testing program, focusing on the shallower Eocene reservoir and our main target of the Oligocene reservoir.“
As previously reported in March 2012, the first drill stem test on the Kurdamir-2 well resulted in a major oil discovery in the Oligocene interval. The well was then drilled to a total depth of 4,000 metres in June 2012. In addition to the oil-bearing intervals encountered in the Oligocene and Eocene reservoirs, hydrocarbon shows and wireline logs indicated the presence of a gross hydrocarbon-bearing interval of approximately 500 metres of fractured limestones and marls in the Shiranish Formation, which was the focus of the recent testing program.
The Shiranish testing program consisted of three cased hole tests over a 221 metres gross interval and resulted in the flow of light, 39 to 40 degree API oil at sub-commercial rates. Further evaluation, including additional analyses of the test results, followed by the already planned extensive 3D seismic program, will be required to better understand if the Shiranish is likely to have commercial reservoir characteristics.
The Company is encouraged that the Shiranish testing program recovered oil from a depth that is significantly deeper than the limit of closure of the Kurdamir structure at the Cretaceous level as mapped from seismic data. This finding supports the observation that the Shiranish reservoir, in a similar fashion as the Oligocene reservoir, is also involved in a considerably larger trap and that Kurdamir and the neighbouring Tophkana structure share a common oil accumulation in the Shiranish reservoir.
The testing operations in the Shiranish interval were concluded on October 9, 2012, following a number of delays due to downhole tool problems. Preparations are currently underway to conduct a cased hole testing program on the interpreted 275 metres of gross oil pay in the Eocene before moving further uphole to conduct additional testing on the main zone of interest in this well, the 118 metres of gross oil pay already discovered in the Oligocene.
The operator, Talisman (Block K44) B.V. and WesternZagros are also planning a 3D seismic program over the Kurdamir and Topkhana structures and a further appraisal well (Kurdamir-3) to assess the ultimate size of the Kurdamir discovery. WesternZagros and Talisman each have a 40 percent working interest in the Kurdamir Block, with the Kurdistan Regional Government holding the remaining 20 percent.