Numerical modeling of cryogenic fracturing process on laboratory-scale Niobrara shale samples

Abstract

Cryogenic fracturing is a new fracturing concept that uses cryogenic fluids as fracturing fluids. Its mechanism rests on the effect of a thermal shock (sharp thermal gradient) introduced by cryogen on the hot surface of reservoir rock. Fractures can then be initiated and propagated due to strong local tensile stress. The objective of this research is to simulate the cryogenic fracturing experiments on Niobrara shale samples. The experimental processes are simulated under different conditions and matched with the actual experiment results. The influences of different confining stress, injection pressure and failure criteria are identified by comparing results from modeling and experiments. The simulation tool developed can also predict the distribution of artificial fractured samples.