Evaluation of Reservoir Characteristics of Well Kot-Sarang-2, Potwar Plateau, Pakistan Using Geophysical Logs

摘要

Present study deals with reservoir characterization of Kot-Sarang-2 well, located in central part of Potwarplateau of Upper Indus Basin, District Chakwal. The geological structure of the Potwar Basin is the product of theTertiary Himalayan orogeny, which resulted in the formation of complex fold and thrust belt in this region. In thepresent work, an attempt has been made to delineate zones having fair shows of hydrocarbons accumulation. Inaddition to this, estimation of reservoir properties and formation evaluation using wireline logs is also the foremostobjective of this study. Based on the wireline logging results, three zones have been marked. Paleocene LockhartLimestone (3967m to 4045m), Permian Wargal Limestone (4160m to 4245m) and Permian Amb Formation (4246m to4285m) are possible reservoirs encountered. Physical properties i.e. total porosity (豻), effective porosity (谽),resistivity of water (Rw), saturation of water (Sw) and saturation of hydrocarbons (Sh) are calculated. For the calculationof saturation of water (Sw) both Archie抯 equation (Swa) and Indonesian equation (Swi) are applied. Results show thatAmb and Wargal formations are showing fair to good saturation of Hydrocarbons (Sh) i.e.73% and 88% respectively,but this is due to high resistivity values of these formations and porosity log also giving very low values. Effectiveporosity for zones Lockhart, Wargal and Amb are 2.56%, 3.5% and 1.32% respectively. Based on these results it isinferred that these formations have low potential for an economically feasible production of hydrocarbons.