A study of relative permeability parameters on rock cores using a two-phase flow test

Abstract

To ensure sequestration safety, confirming the injectivity of the reservoir rock formation is of critical importance, requiring studies of the rock permeability to uncover the fluid migration scenarios within the porous reservoir rock. Two-phase (super-critical CO 2 -brine) flow behavior following the post CO 2 injection is believed to be a dominating factor; its flooding behavior within the porous rock media needs to be further clarified prior to confirming the feasibility of domestic CO 2 geo-sequestration. This study aims to determine the relative permeability of rock cores obtained from field outcropping. A test facility was established to determine the relative permeability during drainage and imbibition processes using a core-flooding test characterized by displacement method. The test facility was assembled locally and is regarded as a pioneering attempt. By relevant data interpretation, the parameters of relative permeability for predicting the movement of super-critical CO 2 after injection can be modeled. More reliable parameters can be obtained using history matching processes wherein time-elapsed data calibration is used in conjunction with a computer code, TOUGH2. The test results were iteratively calibrated using numerical simulation by conducting a history matching process. The K-S curves derived from best-fit parameters are believed to be the most relevant relative permeability for the reservoir rock. Through this preliminary study, a better understanding of some of the problems and limitations associated with the determination of the rock relative permeability using two-phase flow test is achieved, but more advanced research is required.

Experimental Study on Relative Permeability Characteristics for CO2 in Sandstone under High Temperature and Overburden Pressure

“…In CO 2 geological storage engineering, the reservoir roof serves as the main isolator medium, and its permeability and porosity directly affect the CO 2 storage efficiency and the time of safe storage. Thus, scholars have carried out extensive experimental and theoretical research on rock permeability and pore structure [27][28][29][30][31][32]. Fatt et al [33] studied the relationship between sandstone permeability and overburden pressure/confining pressure and found that permeability was negatively correlated with the two pressure forms, and the variation was notable in the low-pressure area.…”