Enhanced recovery from a fractured reservoir using high impact biostratigraphy: A case study from the Fim Kassar Oil Field, Pakistan

Scope and method of study. The purpose of this study was to integrate several data sets to solve a geologic problem. The problem investigated was how fractured carbonate reservoirs can be exploited successfully. This was accomplished by identifying the style of fracturing, then isolating fracture prone beds, and then creating a sequence stratigraphic model that would predict the occurrence of these beds in the subsurface.; Findings and conclusions. The Fim-Kassar anticline is analogous to the Khair-E-Murat anticline as both are composed of the Sakesar and Chorgali Formations. Both structures show small-scale mechanical stratigraphy in the sense that some layers are more prone to fracturing than others. Layers that are composed of microspar matrix are more prone to fracturing than layers that have dolomitic matrix. From basin towards land the following six lithofacies were recognized: Forebank facies, Bank facies, Back-bank facies, Subtidal inner lagoon facies, Intertidal facies, Supratidal facies. Two distinct payzones were recognized on the basis of porosity and fracture occurrence. An identification key was created for well-site geologists such they can biosteer the drill-bit keeping it within the confines of the payzones.