A Sensitivity Study of Pressure Monitoring to Detect Fluid Leakage from Geological CO2 Storage Site.

Abstract: Large volume of CO2 may be stored in depleted oil and gas reservoirs or in deep saline aquifers to mitigate global warming. Once injected, monitoring is of essential need to ensure that the injected CO2 is in place and does not disturb the integrity of formation reservoirs. To this purpose, detection of any risk conditions of fluid leakage to overlying formations is critical. We previously presented the applicability of a pressure monitoring to directly monitor the leakage of carbon dioxide or subsurface brine by measuring the pressure of the upper formation based on the idea of quick response of pressure propagation in a porous media. Especially, it was reported that the pressure monitoring is useful even in the offshore storage site where conventional monitoring method in the onshore site cannot be applied, and it might be cost-effective if the pressure sensor is installed in the injection well. However, the preliminary results based on the numerical simulation are in need to be further investigated with field measurement under a variety of conditions. These various conditions are studied by conducting sensitivity analysis on the pressure change and the detection time. [Copyright &y& Elsevier]