The results of Mputa-2 confirm that the upper reservoir sands intersected in Mputa-1 and Waraga-1 are laterally extensive, but at this location are water wet. Pressure data indicates that the hydrocarbon column height in the upper zone of the Mputa field is potentially of the order of 100 meters, although at this upper level, the Mputa and Waraga structures do not have a common oil leg. The implications of this pressure data and the fact that the target sands came in over 100 meters shallow to prognosis are both positive to the interpretation of the Mputa Field; the new data is being integrated with existing models in order to provide estimates of oil in place for these upper sands shortly. The extent to which these sands will flow commercial volumes of oil will be determined when flow testing operations begin on Waraga-1, expected to commence mid June.
Oil samples have been recovered from the lower reservoir zone in Mputa-2, which can be correlated to similar oil bearing zones in both Mputa-1 and Waraga-1. The presence of oil saturated sands in these basal units in all wells drilled to date implies an extensive stratigraphic trapping mechanism at this level. The gross interval of these units is variable and there does not appear to be pressure communication between them. But contained within the sequence are obvious oil bearing zones of around 5 meters thickness that will be flowed in our testing program at Waraga-1 to determine whether they are capable of sustaining commercial flow rates. The information derived will then determine which of either Mputa-1, or Mputa-2, or both, will be subsequently tested. Assessing where the thicker sand units and more extensive net pay exists in these sequences will be key to their commercial potential and the need for 3D seismic acquisition is currently being evaluated.
The results from the three discovery wells and the testing program will be integrated to define the reserve estimates, commerciality and potential development scenarios for the onshore area. Planning for additional exploration/appraisal wells onshore and a test of a prospect just offshore has commenced with onshore drilling scheduled for 4Q 2006. Plans for the acquisition of further 2D seismic in the north of the block are also well advanced.
Most Popular Articles