Study of Mechanical-Elastic Parameters of Reservoir Rocks with Respect to the Purpose of Permanent CO2 Storage

CO2 emissions are considered to be partly responsible for climate change. One of the available methods to reduce CO2 emissions is its storage in favorable rock structures, such as mined hydrocarbon deposits. Natural hermeticity is guaranteed with this reservoir structure. An increase in pressure conditions in the deposit, induced by long-term CO2 storage, can lead to the splitting of exposed rocks. It is therefore necessary to carry out geomechanical tests on available drill core samples. The presented article presents the results of laboratory research aimed at determining the mechanical-elastic parameters of reservoir rocks of a hydrocarbon deposit using non-destructive testing. The advantage of this method is the possibility of testing the given samples before and after exposure to CO2. The laboratory research carried out revealed significant differences in the measured mechanical-elastic parameters of the tested samples. Taking into account that samples of the consistent reservoir structure of the same deposit were tested, the necessity of detailed testing of geomechanical parameters arises. It was interpreted that the differences in mechanical-elastic parameters found by the research may be caused by differences in the lithological composition (for these purposes, XRD powder diffraction was implemented), or by mechanical disturbance given, for example, by fracture predisposed by structural-tectonic processes. Different humidity can also have an effect, or degree of saturation of the tested samples.