Manambolo block is the smallest of the blocks at 3,995 square kilometers (1.0 million acres). The prospect on this Block was not well defined by the pre-existing seismic data; however, prior drilling in 1987 encountered the best well test in Madagascar. The seismic data was correlated to six prior wells on the western portion of the block. Four of the wells had oil and gas shows during drilling, but did not produce on test. The one 1987 well that showed promise was West Manambolo #1, which was drill stem tested and flowed 15.6 mmcfd. The well was abandoned by the operator as non-commercial, in large part due to lack of infrastructure and market. Subsequent 2009 seismic and geologic analysis indicates that the WMBL #1 gas interval migrates to surface with no potential trapping locations present.
The 2009 seismic analysis has developed two prospective areas as indicated below;
The two Prospective Areas cover over 38,000 acres in the central portion of the block.
•The leads are based on stratigraphic pinch-out sequences in three (Seq.1-lower, Seq.2-middle and Seq.3-upper) Cretaceous aged depositional sequences.
♦Prospective Area 1; U,M,L Cretaceous sequences mapped, total area > 16,000 acres
♦Prospective Area 2; U,M Cretaceous sequences mapped, total area > 22,000 acres
•Numerous oil and gas shows down-dip in East Manambolo #1, Serinam #1 and Manambolo #1 wells encountered providing good indication of hydrocarbon presence.
•Evidence of hydrocarbon charge is weak and requires further study.
Prospective Area 1 was a direct outcome of the 2009 seismic acquisition. Prospective Area 2 resulted from applying interpretation adjustments identified in 2009 seismic to prior seismic data. The Prospect Area 2 results are based on a fairly widely spaced data set.
The seismic section across Prospective Area 1 shown below highlights the 3 pinchouts that will be examined.
Conclusion
•These mapped stratigraphic zones do not represent drillable prospects at this time.
•Oil/gas shows downdip of the prospective areas are encouraging indications of an active petroleum system, but they do not definitively support the existence of a hydrocarbon trap.
•To ascertain the existence and extent of any hydrocarbon accumulations, it is the plan in 2010 to:
♦Acquire 160 sq/kms of GORE surface micro seepage data for Prospective Area 1 updip of the Manambolo wells where new seismic was acquired in late 2009.
♦Acquire 160sq/kms of GORE surface micro seepage data for Prospective Area 2 to confirm the shallow gas zone in the SER-1 well and the possibility of trapped hydrocarbons in several deeper zones. If the GORE survey indicates hydrocarbon potential it is likely additional seismic acquisition will be required over the prospect area.
