By OGJ editors
HOUSTON, Nov. 29 -- Apache Corp.’s appraisal of the 1976 Spar discovery off Western Australia flowed gas-condensate at such a rate that partner Santos Ltd. said the volume of recoverable gas “is expected to be significantly greater than the 335 petajoules gross previously stated.”
Apache, operator of the WA-4-R permit in the Carnarvon basin since the end of August, tested the Spar-2 appraisal well at a facilities-constrained rate of 58 MMcfd of gas and 950 b/d of condensate on a 1-in. choke.
The well, which cut 55 m of net pay in the primary target Upper Barrow reservoir, has been completed as a producer. The site is 70 km west of Varanus Island.
Santos said the well also intersected 40 m of net gas pay in several sands in the deeper secondary exploration target, the B Reticulatum zone. That zone drillstem tested 5 MMcfd and 6 bbl/MMcf through a 1-in. choke from a 12-m section.
Apache’s Australia subsidiary will bring gas from Spar field and nearby Halyard field to Western Australia’s domestic gas market via an existing Apache-operated pipeline 10 miles southeast of Spar-2 and through the Varanus Island processing and transportation hub.
Halyard is to start up at 50 MMcfd in the second half of 2011, and Spar will follow in late-2012 as capacity opens on the island.
Apache owns a 55% interest in WA-4-R and adjacent WA-13-L, where Halyard is located. Santos owns the remaining interest.
Spar-2 was completed over a perforated interval of 131 ft within 163 ft of high-quality gas pay in a single zone at the top of the Barrow Group formation. The appraisal is 1 mile southwest of the Halyard-1 discovery and 18 miles southwest of Apache’s John Brookes platform.
Halyard-1, drilled in 2008, test-flowed at a peak 68 MMcfd of gas and 936 b/d of condensate from 91 ft of net pay in the Cretaceous Halyard sandstone.
On release from Spar-2 the rig will move to the nearby WA-290-P permit to drill the Apache-operated Zola-1 exploratory well in which Santos has a 24.75% interest. Apache and Santos plan to drill the Beam prospect in 2011 located in WA-13-L.
Santos purchased Spar after Chevron Australia determined it was surplus to the Greater Gorgon LNG development (OGJ Online, Sept. 20, 2008).
Flow high at Spar appraisal off W. Australia
By OGJ editors