EVALUATING RESERVOIR BUILD UP TEST IN SOME SELECTED XYZ WELLS IN NIGER DELTA
Reservoir Buildup test is the measuring the well’s sand face pressure variation with time while well is shut in. The tests are economical to run and correct analysis of such tests yields information about the reservoir and well properties. This research work discusses the daily experience gained from analyzing several tests ran in the Niger Delta wells. The tests were ran with Amerada and high precision electronic gauges. Our analysis methods include the conventional method, manual type-curve method and automated type-curve analysis methods. Our results show that the available manual type-curve cannot fit data from most Niger Delta wells because of the high skin and permeability values. Also, results obtained by evaluating the test with conventional and automated type-curve method agree reasonably in situations where the well-bore storage effect dies down early and transient state flow observed. Our results show that factors that make it difficult to analyze and evaluate tests ran in Niger Delta wells include: (a) Poor precision of gauges used (b) Unusually long well-bore storage duration. (c) Interference effects. Also our results show that the ratio of pressure drop due to damage-skin to pressure drawdown is a better yardstick for ranking acid stimulation candidates.
Pressure, Permeability, Skin factor, build up test, shut down, well bore storage, Trasient state, Interference effect and Storage duration.