Process-based and dynamic 2D modeling of shale samples: Considering the geology and pore-system evolution

Abstract

Accurate characterization of shale samples is of great importance for predicting and evaluating their intrinsic properties as they undergo various geological processes. As such, constructing shale models not only entails accounting for the numerous components and pores, but also requires considering the effects of thermal maturation on the evolutions of the pore systems and components. In this study, a new dynamic and process-based modeling for considering the geological evolutions occurred in pore systems is developed, which makes a significant improvement in reproducing the complex geological features in shale samples. Three types of pores, including organic matter (OM), interparticle (interP), and intraparticle (intraP) pores, and several other components including kerogen, pyrite, clay minerals, globigerinids, calcite, feldspar, quartz, and petroleum products, are all considered in our process-based modeling. In order to demonstrate the performance of our process-based method, two-dimensional (2D) dynamic shale models of multiple cases with different geological processes are constructed. Then, to characterize the constructed samples, the occurrences and distributions of all components are studied using a two-point correlation function. Aside from statistical comparisons, the gas flow in these shale models is also simulated to exhibit the permeability variations produced in the process-based models. Moreover, the degree of cementation, the fractions of interP, intraP, and OM pores are varied to mimic new geological scenarios, which aims to further evaluate the performance of the proposed technique. The results indicate that our process-based model presents an excellent performance. Furthermore, the presented modeling technique can be extended to investigating the effects of various components and pores on the intrinsic properties of shales in the future.