Reservoir capacity estimates in shale plays based on experimental adsorption data

2015 Spring. ; Includes illustrations (some color), color map. ; Includes bibliographical references (pages 63-68). ; Fine-grained sedimentary rocks, such as mudrocks, are characterized by a complex porous framework containing pores in the nanometer range that can store a significant amount of natural gas (or any other fluids) through adsorption processes. Unfortunately, although the adsorbed gas can take up to a major fraction of the total gas-in-place in these reservoirs, the ability to produce it is limited, and the current technology focuses primarily on the free gas in the fractures. A better understanding and quantification of adsorption/desorption mechanisms in these rocks is therefore required, in order to allow for a more efficient and sustainable use of these resources. Additionally, while water is still predominantly used to fracture the rock, other fluids, such as supercritical CO2 are being considered; here, the idea is to reproduce a similar strategy as for the enhanced recovery of methane in deep coal seams (ECBM). Also in this case, the feasibility of CO2 injection and storage in hydrocarbon shale reservoirs requires a thorough understanding of the rock behavior when exposed to CO2, thus including its adsorption characteristics. Shale reservoirs are widely distributed in the U.S. with existing infrastructures used for gas and oil production operation; should CO2 injection in such reservoirs prove feasible, the capacity of geologic formations for CO2 storage will increase significantly. The main objectives of this Master's Thesis are as follows: (1) to identify the main controls on gas adsorption in mudrocks (TOC, thermal maturity, clay content, etc.); (2) to create a library of adsorption data measured on shale samples at relevant conditions and to use them for estimating GIP and gas storage in shale reservoirs; (3) to build an experimental apparatus to measure adsorption properties of supercritical fluids (such as CO2 or CH4) in microporous materials; (4) to measure adsorption isotherms on ...