A Material Point Method Based Tool for Modeling Diagenesis

James Guilkey, Linda Bonnell, Robert Lander, Omar Alsolaiman

Keywords: sand, sandstone, contact, cohesive zone

TL;DR: By adding features to an MPM code we can model many of the processes involved in the formation of sandstone from individual grains of sand.

Abstract: Sandstone is created when a collection of individual grains of sand are subject to a variety of geologic processes. These include; mechanical compaction, due to deposition of overburden, chemical compaction, in which dissolution takes place at intergranular contacts, precipitation, in which grains grow due to, e.g., quartz overgrowth, and formation of intergranular bonds due to, e.g., carbonate cement. We have created Cyberstone, which begins by depositing hundreds to thousands of individual sand grains, after which a version of the Uintah-MPM code is used to represent all of the aforementioned processes. This has provided a virtual laboratory in which entirely synthetic rocks can be created and compared to physical samples, thereby allowing an investigation of the processes and their parameters that led to the state of those samples. We will describe the approach and show results from recent case studies.