Use of discrete particle modeling to understand stress-release effects on mechanical and petrophysical behavior of granular rocks

Discrete particle modeling with PFC^3D has been used to simulate effects of stress release associated with coring of rock from deep boreholes. Stress release leads to core damage. PFC has been used, together with laboratory simulations on synthetic sandstone formed under stress, as a tool to understand and quantify this damage. The combined use of experimental and numerical modeling has contributed to the development of a procedure for core damage correction of compaction data, and also to improved assessment of overburden corrected core porosity. A further result of core alteration is the establishment of stress memory in the core material. PFC^3D has been used here to verify the feasibility of a novel technique for in situ stress determination based on use of this stress memory.