A probabilistic assessment of geomechanical reservoir integrity during CO₂sequestration in flood basalt formations

Abstract

Recent field experiments in Iceland and Washington State (USA) show that basalt formations may be favorable targets for carbon capture and sequestration (CCS) because CO2 mineralization reactions proceed rapidly. These results imply that there is tremendous opportunity for implementing CCS in large igneous provinces. However, the magnitude of this opportunity comprises commensurate levels of uncertainty because basalt reservoirs are characterized by highly heterogeneous, fracture‐controlled hydraulic properties. This geologic uncertainty is propagated as parametric uncertainty in quantitative risk models, thus limiting the efficacy of models to predict CCS performance attributes, such as reservoir integrity and storage potential. To overcome these limitations, this study presents a stochastic approach for quantifying the geomechanical performance attributes of CCS operations in a highly heterogeneous basalt reservoir. We utilize geostatistical reservoir characterization to develop an ensemble of equally probable permeability distributions in a flood basalt reservoir with characteristics of the Wallula Basalt Pilot Project. We then simulate industrial‐scale CO2 injections within the ensemble and calculate the mean and variance of fluid pressure over a 1‐year injection period. These calculations are combined with the state of stress in southeast Washington State to constrain the spatial extent at which shear failure, fracture initiation, and borehole breakdown may occur. Results from this study show that (i) permeability uncertainty alone causes injection pressure to vary over 25 MPa, (ii) shear failure is likely to occur at 7 times greater distances from the injection than the CO2 migrates, and (iii) joint initiation pressures are localized within the volume comprising the CO2 plume. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

A review of carbon mineralization mechanism during geological CO2 storage

“…On the other hand, at the temperature of 60–100 °C, magnesite and ankerite formation was observed. According to Jayne et al [ 56 ], CCS aiming at basalt formations is very challenging to computationally model due to its heterogeneity and fracture-controlled hydraulic properties. The authors adopted the geostatistical reservoir characterization method with TOUGH3, which quantifies the permeability uncertainty and potential for the joint initiation and shear failure.…”

Dynamic analysis of geomaterials using microwave sensing

“…These sectors are primarily concerned with rock damage, natural or by human influence, and the dominant fluid flow pathways through altered rock units. The importance of rock integrity and reservoir systems elements mapping across multiple key energy sectors are well defined for oil and gas (O&G) 28 , 29 , carbon capture and storage (CCS) 30 – 36 , geothermal energy extraction 37 – 40 , nuclear waste disposal 26 , 41 – 43 and mining operations 44 – 46 . For example, the generation of nuclear energy throughout the lifecycle of a powerplant creates extremely long-lived waste products, which must be reliably isolated from the geosphere and biosphere.…”

A study on the impact of storage boundary and caprock morphology on carbon sequestration in saline aquifers

“…Reservoir pressure build‐up may result in fracture propagation and reactivation, 47,48 shear or joint dilation, 49 induced seismicity, 50 and fault and displacements 51 . The geomechanical response of a storage site to CO 2 sequestration requires a comprehensive understanding of regional tectonic stresses, mechanical reservoir properties, and orientations of pre‐existing discontinuities (faults and fractures) within the reservoir 52 . Therefore, the geomechanical integrity of the storage site should be evaluated carefully as part of the risk assessment process 53 .…”

“…51 The geomechanical response of a storage site to CO 2 sequestration requires a comprehensive understanding of regional tectonic stresses, mechanical reservoir properties, and orientations of pre-existing discontinuities (faults and fractures) within the reservoir. 52 Therefore, the geomechanical integrity of the storage site should be evaluated carefully as part of the risk assessment process. 53 A portion of the injected CO 2 dissolves in the resident brine and produces carbonic acid.…”