Experimental studies on gas dissipation during the coring process of shale

Abstract

A series of experiments were performed to study the influence of initial pressures and pressure drop rates on the amount of lost gas during the coring process. The change laws of cumulative gas production and gas production rate were investigated. The proportion changes of lost gas, desorbed gas, and residual gas were analyzed. The results show that the cumulative gas production can be divided into three stages. There is a step with a relatively stable gas production rate in the gas production rate-time curve. The proportional change curves of the lost gas and desorbed gas have the same turning point.