Abstract
Abstract
Carbon dioxide geological storage is considered one of the crucial technologies that can permit to mitigate the greenhouse gas emission impact. The storage site characterization through laboratory studies is important to assess feasibility and mitigate the risk.
In this work we present a series of core-flooding experiments necessary to acquire the fluid flow parameters and behavior at reservoir conditions. CO2 supercritical stream was mixed with methane in two sets at 5% and 10% of CH4. Core-flooding tests were conducted at high pressure (HP), up to 375 bar and high temperature (HT), up to 180°C.
HP-HT core-flooding rig and a "4D" X ray tomographic rig were used, permitting to accurately monitor the effect of fluids propagation, breakthrough, and production in the porous core samples. Different set of relative permeability experiments were conducted adopting both Unsteady and Steady State methodologies. The experiments followed laboratory methodologies necessary for reservoir condition aiming also to improve the existing protocols and maximize the acquired data quality.
Core Plugs in a broad range of permeability (0.1-600 mD) were tested. X-ray tomography permits to evaluate the effect of heterogeneity. The X-ray volumetric data, acquired continuously during the flooding, were converted in linear profiles of saturation. The latter together with additional conventional fluid and gas inlet-outlet mass balance and accurate pressure monitoring permitted to assess good quality relative permeability data. Flow behavior with observed dynamic phenomena is discussed. The CO2 contamination with methane did not significantly affect the injectivity.
Core flooding results, injectivity behavior with observed dynamic phenomena are presented. The CO2 stream contamination with methane and the harsh conditions, in particular the high temperature is not common in experimental works (Rizzato et al 2019).