04 November 2004: Survey Results in Nambia
Circle Oil plc is pleased to announce the completion of a recent airborne gravity and magnetic survey of its concession in Northern Namibia. The survey was aimed at evaluating the hydrocarbon potential in an area with no previous seismic coverage or modern gravity or magnetic data. Interpretation of this data has defined basinal areas, regional lineaments and structural highs, each of which is critical in understanding the regional petroleum system.
A total of six deep basins were defined by the survey and four of these have been selected for additional surveying. The Company anticipates that, following an aggressive exploration programme over these areas, a number of new prospects will be brought to drillable status in the near future. Future activity will probably include additional gravity-magnetics and/or 2-D seismic surveys to further refine the hydrocarbon potential of this large area. There are already two prospects, delineated by previous seismic programmes, to the west of the area surveyed that are ready for drilling.
The survey was carried out over 75,618 sq. km. of the eastern portion of Circle's 146,000 sq. km. concession area of the Owambo (Etosha) Basin in northern Namibia. The Owambo basin is located about 500 km. north of Windhoek, the capital of Namibia, and in its entirety covers approximately 268,000 sq. km. of Namibia and southern Angola. The detailed stratigraphy of the basin is poorly understood due to the extensive blanket of post-Cenozoic Kalahari sediments. Most of the information is known from outcrops along the basin margins, from a small number of widely spaced wells, from limited seismic coverage in the western half of the basin and from regional aeromagnetic and ground gravity surveys.
A reconnaissance soil gas survey conducted by a previous operator over a 10,000 square kilometer area contained several significant anomalies, suggesting active migration of petrogenic hydrocarbons from depth. These surface petrogenic microseeps have an overall gassy to ntermediate compositional source. Anomalous surface microseeps over a surface-expressed anticlinal structure in the western part of the survey area have an oily to intermediate compositional source. There is a good correlation between higher hydrocarbon magnitudes at the surface and areas of structural deformation mapped at the surface and in the subsurface.
Examples of Proterozoic source rocks and production similar to those under evaluation in Namibia include Oman where these rocks in the South Oman and Ghaba salt basins contained proven reserves of approximately 3 billion barrels of oil. In Eastern Siberia in the Lena-Tunguska province, Proterozoic source rocks and reservoirs contained proven reserves of 18 tcf of gas, 425 million barrels of condensate and 220 million barrels of oil while estimated reserves in the Sichuan Basin of South Central China from Proterozoic and Cambrian source rocks and Proterozoic reservoirs are 40 tcf of gas with 10% from the older reservoirs.
David
Hough, Managing Director, commented,
'These results are most encouraging and further highlight the
significant potential of this very large license area. A number of major oil
companies have expressed their interest in Circle's Namibian prospects and these
results will greatly strengthen our hand in any negotiations that may take place
over the coming months.'
For further information please contact,
David
Hough, Managing Director
Circle
Oil PLC
Tel. +353 61 354831
Chris Roberts / Ben Simons
Hansard
Communications
Tel. 020 7245 1100