Hydrocarbon Evaluation of Lower Eocene Age Limestone of Qadirpur 14 & 15, Central Indus Basin Pakistan

Abstract

The objectives of the study is to evaluate reservoir properties of Sui Main Limestone of lower Eocene age in Qadirpur 14 and 15. Qadirpur gas field located in Sindh province, Pakistan. Qadirpur 14 is located at 28°4"12.37' Ν. 69°23"32.59' E and Qadirpur 15 is located at 28°5"32.20° N, 69°23"37.32' E. Tectonically the area is located in extensional regime. To carry out this research, all the logs are required to carry out petrophysical analysis. The methodology to perform petrophysical analysis includes calculation of volume of shale, porosity determination, and hydrocarbon estimation. Log curve behavior shows that there are two pay zones present in Qadirpur 14 and 15. In Qadirpur 14 zone 1 ranges from 1813m to 1825m and zone 2 ranges from 1830m to 1855m. In zone 1 volume of shale is 10.54%, Effective porosity is 13.13%, water saturation is 34.75%, and hydrocarbon saturation is 65.24%. However in zone 2, volume of shale is 20.27%, effective porosity is 14.22%, and water saturation is 34.42%, hydrocarbon saturation 65.57%. Similarly in Qadirpur 15 zone 1 ranges from 1734m to 1750 m and zone 2 ranges from 1756 to 1780m. In zone 1 volume of shale is 17.41%, effective porosity is 13.26%, water saturation is 21.59%, and hydrocarbon saturation is 78.40%. However in zone 2, volume of shale is 24.41%, effective porosity is 15.60%, and water saturation is 23.43%, hydrocarbon saturation 73.56%. Hence result proves that Sui Main Limestone are of high potential as petrophysical analysis suggests very low volume of shale and and good hydrocarbon saturations which is a symbol of good reservoir rock.