Far field pressure monitoring well spacing in open basins with multiple sequestration sites

Geologic carbon sequestration is regulated under USEPA's Underground Injection Control program, specifically under Class VI regulations. Injection zone pressure monitoring wells will be installed at many Class VI injection sites. Selecting locations of these monitoring wells that will provide pressure data during the life of the project to track the pressure "plume" is an engineering, regulatory, and economic challenge. Monitoring well locations will be affected by the monitoring objectives (e.g. far field pressure), geologic environment, and permeability anisotropy. Our study uses numerical simulations to determine locations for monitoring near and far field pressures over time. We conducted simulations of CO2 injection into the basin using geostatistically-based geocellular models with different permeability distributions i.e. randomized and directional permeability distributions. For these simulations, a fixed injection pressure for each well influences the spacing between injection wells and the optimal locations of the pressure monitoring wells. In addition to other CO2 injection sites, natural gas storage projects will also limit locations of CO2 injection sites, and may play a more important role in pressure monitoring well locations.