The Dunsborough-1 has been drilled to a Total Depth of 1,755 meters Below Rotary Table and a comprehensive wireline electrical logging and fluid pressure and sampling program has been completed. Preliminary interpretation suggests that the well has intersected a minimum 25 meter gross hydrocarbon column of which approximately 18 meters is net pay. The accumulation appears to have a small (<13 meters) gross gas column above an oil column containing light oil (approximately 40 degree API) in sands of poor to moderate reservoir quality. Pressure data indicate that the total gross hydrocarbon column associated with the Dunsborough structure may be up to 70 meters. Tentative volumetric estimates by ROC suggest that the structure could contain between 20 and 40 million barrels of oil in place.
Dunsborough-1, located approximately 25 km south of Geraldton, Western Australia and about 50 km northwest of the Cliff Head Oil Field, is the third and final well in an offshore Perth Basin drilling program which was initiated in early April, 2007 by the WA-286-P and WA-325-P joint ventures, both of which are operated by ROC. The program’s first well was the Frankland-1 gas discovery in WA-286-P, about 25 km southeast of Dunsborough-1, the program’s second well was the Perserverance-1 gas discovery in WA-325-P, approximately 50 km to the northwest of Dunsborough.
Commenting on the three well program ROC’s Chief Executive Officer, John Doran stated that:
“It is always nice to drill three offshore exploration wells and make three discoveries, particularly when that extends the known oil and gas fields some 200 kilometers along regional strike to the northwest of the Cliff Head Oil Field. However, at the end of the day we’re not looking to play with exploration success statistics but rather to clock up commercial success - and it will take some time to establish whether or not we have done that.
Of the three discoveries, Frankland and Dunsborough look as if they have the best chance of being developed, while Perserverance will probably need a lot of good things to happen around it if is going to make the grade.
Whatever the details, it would seem that an exploration program that was regarded by ROC as the last throw of the dice in the northern offshore Perth Basin, has certainly provided enough success to cause us to move the discoveries on to the appraisal stage and continue to explore around and on trend from them.”
Participating Interests in WA-286-P are Roc Oil as operator with 37.5 percent; AWE with 27.5 percent; Wandoo Petroleum with 24 percent; ARC Offshore with 6 percent and CIECO Exploration and Production with 5 percent.
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