2D Seismic Interpretation And Petrophysical Analysis Of Dina Oil Field, Upper Indus Basin, Pakistan

Abstract

This study presents a thorough analysis of seismic data and petrophysical properties of the Shahab-01A well in the Dina area of the Upper Indus Basin, focusing on the Chorgali Formation and Sakesar Limestone reservoirs. The research covers the interpretation of five seismic lines 942-DNA-55, 942-DNA-68, 942-DNA-71, 942-DNA-73, and 942-DNA-74. Through detailed seismic interpretation, significant structural thrust faults and stratigraphic features were identified, providing valuable insights into subsurface geology. The thrust faults that are identified in the interpreted seismic sections are F1, F2, F3 and F4 which are correlated on all seismic sections and reveal pop-up structure with thrust sheets. The shallowest pop-up structure is observed between F1 and F2 while another pop structure is present between F3 and F4, but it is deeper than the previous pop-up structure. The analysis offers essential information on the distribution and characteristics of the Chorgali Formation and Sakesar Limestone. Under the petrophysical analysis section of the research area, two possible zones within the Chorgali Formation and four zones within the Sakesar Formation were identified as areas of interest. The results indicate that the Chorgali Formation can be segregated into two distinct facies, which are Limestone and Shale while Sakesar consist of only Limestone. In the petrophysical analysis it has been identified that the zones fulfil all the four criteria of zone of interest. Sakesar zones clearly show more hydrocarbon potential than the Chorgali zones after a thorough investigation. Sakesar zones have Vsh of 28.8% and φE is 4.7% and Sh is 34.5%. Whereas in case of Chorgali zone has a Vsh of about 24.4 and φE of 13.2% and Sh of 27.7%. Drilling at the Shahab-01A well was stopped because of a fishery, a mechanical failure in which the drill bit got loose and got stuck in the wellbore.