Experimental and Simulation Studies of Cryogenic Effects in the Near-Wellbore Region

Abstract

AbstractWe modified our parallel thermo-hydraulic-mechanical simulator of fully coupled multiphase fluid and heat flow and geomechanics in porous and fractured media to simulate cryogenic fracturing with liquid nitrogen. This included developing a physical property module for nitrogen-water systems and formulating fracture initiation and extension criteria.We simulated cryogenic fracturing experiments on small concrete blocks to verify the simulator modifications. Then, we simulated two field cases, one with an injector-producer pair with cryogenic fracturing that enhanced the permeability in a vertical plane around the wellbore and extending in the direction of the producer. The second case was cryogenic fracturing and cooling of the near-wellbore region in a shallow, heated reservoir. The induced fractures were horizontal but their lengths were non-uniform due to the pressure and temperature gradients.