After being granted Block 52, Circle replicated the approach employed following the acquisition of Block 49, copies of the 10,540 km of previously acquired 2D seismic and three wells drilled in the Block were obtained, along with the associated gravity and magnetic data. This historical data was re-assessed as part of initial studies on the Block.
A satellite based seep study was commissioned in 2006 and in 2007 a comprehensive 6,000 km regional 2D survey was completed for Circle by TGS-NOPEC. These data were processed over Winter 2007 and Spring 2008 and the data were interpreted by Circle’s own technical team to produce a full report, documenting a number of interesting structural and stratigraphic leads as potential targets for drilling.
In order to firm up the identified leads an additional 5,026 line km of 2D seismic data was acquired and completed in February 2011. This has been processed and the interpreted data has been incorporated into farmout brochure for a farmout exercise for late summer 2011. The farm-out process is aimed at seeking a partner(s) to drill a commitment well in Block 52.
Circle’s interpretations detailed in the farmout package for Block 52 have identified several promising play types in stratigraphy ranging in age from Pre-Cambrian to Tertiary, but the offshore Outer Sawquirah Area of Late Cretaceous to Palaeogene structural closures is considered the most prospective.
The identified principal reservoir intervals are Palaeogene Hadhramaut carbonates and clastics and late Cretaceous Aruma Group carbonates. Potential source rocks are considered to be Lower Hadhramaut and Aruma shales with additional potential in the basinal Jurassic Sahtan Group and the Infra-Cambrian Huqf Super Group. Sealing units for potential traps are provided by extensive shale units of the Fars, Hadhramaut and Aruma groups.
Nine large four way dip closed prospects are recognised in the Outer Sawqirah Area. Internal pre-drill deterministic STOIIP of these nine prospects for the most likely unrisked case is calculated as 7,264 MMBO. The associated ultimate recoverable resources for the nine prospects are estimated internally as 2,179 MMBO.
The water depths for proposed drilling locations on the nine prospects range from 724 to 956 m and target depths range from 1,490 to 2,850 m. The largest individual prospect, presently designated as Prospect A1, is situated in a water depth of approximately 769m, with an internally estimated deterministic most likely STOIIP of 2,435 MMBO and associated most likely ultimate recoverable resources of 731 MMBO, with depth to top target at 1,490 m.
The Company would emphasize the point that the pre-drill deterministic estimates of STOIIP and resources are based on the information and interpretations available at time of issue and are made based on Circle‘s management deterministic best estimates. There can be no assurance that such estimates will prove to be accurate as future technical evaluations and results, including drilling results, could lead to variations or differ materially from those indicated.