Building a rock physics model for the formation evaluation of the Lower Goru sand reservoir of the Southern Indus Basin in Pakistan

摘要

The geological factors of any reservoir, such as porosity, lithology, and fluid characteristics, control the rock physics models. Several retrospective studies have discussed the methods of discriminating and calculating these geological factors in the Lower Goru sand reservoir. Therefore, it is imperative to build the best-modified suitable rock physics model and template to diagnose an inadequately consolidated reservoir that has been previously overlooked. For the purpose, the research evaluates a dataset of five wells to develop a modified rock physics model and template for a Lower Goru sand reservoir in Pakistan. The study compares and evaluates different rock physic models such as Stiff sand, Friable-sand, Greenberg and Castagna, and Raymer's model to calibrate the best model, which would comprehensively assist the future researchers. According to the results, Stiff sand is quite a suitable rock physics model. Furthermore, the rock physics template (RPT) is utilized to test the reliability of the predicted model that is helpful for the formation evaluation, reservoir characterization, and prospect evaluation across different fields of the Lower Goru sand reservoir. The predicted model can be further used to estimate porosity from the seismically derived impedance in the entire Lower Goru sand reservoir, Pakistan, and worldwide which has the same geological trends and reservoir distribution.