Geocellular Modeling of the Cambrian to Eocene Multi-Reservoirs, Upper Indus Basin, Pakistan

Geocellular modeling has become extremely important, linking all petroleum disciplines, and being widely used in simulation and production forecasting in complex basin studies. In this study, we focused on the Minwal-Joyamair Fields in the Upper Indus Basin (UIB), Pakistan, which contains Cambrian to Eocene reservoir formations. Changes in sedimentary environments and structural activities within the UIB have resulted in reservoir heterogeneity, which has adversely affected reservoir performance, and it is still not fully understood. Geocellular modeling was used in this study to better understand the structural framework of the Cambrian to Eocene formations in the UIB. The 2D seismic and well log data from the Minwal-Joyamair Fields are the primary data for building the geocellular model for the Eocene (Chorgali, Sakesar) and Paleocene (Lockhart) reservoirs. The developed structural model is then populated with petrophysical properties such as porosity. The upscaled porosity for the Eocene carbonate rock units ranges 1-3%. On the other hand, the Cambrian and Permian (Tobra & Khewra) clastic reservoirs bear porosity of 3-10%. The upscaled porosity can be utilized to predict the lateral and vertical distribution in these reservoirs. Furthermore, the evaluated upscaled correlation for Eocene reservoirs (80-90%), whereas for Permian (Tobra) and Cambrian (Khewra) reservoirs, it lies between 60 and 70 %. Apart from data availability, a complete geocellular model of the field was produced, encompassing the petrophysical and facies model. The geocellular models created a high-resolution 3D reservoir model of this complex geology that can be applied to similar geology worldwide to identify prospective zones.