2D Seismic Interpretation and Well Log Analysis of Fazilpur area, Central Indus Basin, Pakistan

Abstract

Fazilpur area is located in Punjab province in District Dera Ghazi Khan. Geographically the area lies between 29º 15’ to 29º 30’ North and 70º 10’ to 70º 40’ East. Stratigraphically, it lies in Sulaiman depression of Central Indus Basin, which is characterized by monoclinal structures. The following study is done for hydrocarbon potential evaluation by integrating the seismic and well log data approaches. The target horizons were marked by making the TD chart using well tops of Choti-01. The target formation in the research area was to test the Sui Main Limestone of Eocene age. The two-way time and depth contour maps prepared as a result of interpretation, have confirmed the presence of Monocline trending East to west. The Time to depth conversion is done using the available stacking velocities on the seismic sections. The Monoclinal structure is shallowing towards east and deepening towards west. Sui Main Limestone of Late Eocene and Dunghan Formation of Early Paleocene are acting as reservoir rocks. Ghazij shale of Eocene age is acting as a regional seal. Petrophysical analysis is done on the well Choti-01 for formation evaluation and potential hydrocarbon baring zones. Two zones, Pirkoh Formation (Zone 1) 15 m in thickness and Sui Main Limestone (Zone 2) 48 m in thickness have been identified on logs respectively. Through the results of petrophysical analysis, zone 2 is more promising for hydrocarbon potential than zone 1 having average Vsh 25% and Vsh 40%, average effective porosity 6% and 3%, average saturation of hydrocarbon 86% and 43% respectively. Due to tight effective porosities in both the zones this well is abundant. Petrophysical analysis at that level of Dunghan Limestone (which is also a proven reservoir) could not be carried out due to the unavailability of well log data.