Manandaza is just to the south of Tsimiroro (Block 3104) and is 6,580 square kilometers (1.6 million acres) in size. The seismic work in 2009 identified one large structure and three smaller structures in the Lower Sakamena sandstone. There have been two prior wells in the block, one of which tested 41 degree API oil on drill stem test, but did not show sufficient potential to pursue further. The south end of the block has features that suggest that potential exists to justify future investigation, but no new work has been completed in that portion of the block.
The large structural closure and 3 leads mapped in the Lower Sakamena sandstone reservoir interval and are shown on the diagram and are as follows:
♦Main Manandaza closure > 14,000 acres
♦Lead 1 > 2,500 acres
♦Lead 2 > 3,000 acres
♦Lead 3 > 3,000 acres
•The Manandaza #1 well tested 41° gravity API oil on a drill stem test. Core results from the interval indicate a very low porosity and potentially a poor quality reservoir.
•Extent of hydrocarbon accumulation at MDZ #1 uncertain due to presence of faulting at the wellbore.
•Hydrocarbon charge and trapping efficiency for additional leads remains a significant risk factor.
The Manandaza #1 well is indicated on Line 76 and is likely to have penetrated the reservoir at the intersection with a fault.
Conclusion
•The mapped structures do not represent drillable prospects at this time.
•The additional data points afforded by the new seismic data aided in a better gridding and contouring methodology for the greater Manandaza area leading to the identification of 3 additional leads.
•A fault cut recognized on the new seismic data at MDZ-1, and encountered in the wellbore, may have adversely affected the reservoir quality and test results.
•The poor quality of the reservoir and the fault cut in the wellbore bring into question the actual size of the accumulation seen in the MDZ-1 even though a robust structural closure exists.
•To ascertain the existence and extent of any hydrocarbon accumulations, it is the plan in 2010 to:
•Acquire approximately 146 sq km of GORE surface micro-seepage data to confirm the areal extent of the Manandaza accumulation and the structural horst, L1 to the east.
•Acquire two additional GORE surveys over L2 (40sqkms) and L3 (53sqkms) for potential hydrocarbon entrapment against basement.
•Consider a hydraulic fracturing stimulation study to determine if, and how effectively, the tight Lower Sakamena reservoir may be produced if the GORE survey indicates broad hydrocarbon presence.
