Scaling Issues in Estimation of Pore Space Using Digital Rock Physics

Abstract

Core samples have always been a luxury for measuring reservoir properties. However, in most cases, the cores become non-usable after a single experiment. The methods such as Digital Rock Physics (DRP) based on image processing offer an alternative to model these reservoir properties with better control on subjective biases of the experimentation and are non-destructive in nature. DRP involves imaging the formation and simulating the field performance to account for various non-homogeneities in the reservoir formation. Over some time, now, it has become a popular method, but in case of complex reservoirs such as carbonates and unconventional resources, it is still at the feasibility stage only. The reasons are plenty ranging from availability of calibration libraries and transition space error and its quantification. In this paper, we used DRP to obtain porosity in carbonate samples at various scales and compared the results obtained using established laboratory methods which at the moment serves as ground truth for reservoir characterization challenges. We found that DRP results mostly align with the results obtained using methods like QEMSCAN. The analysis mostly points to the resolution limit input to the respective techniques.