Geomechanical modelling of CO ₂ geological storage with the use of site specific rock mechanics laboratory data

Abstract

Many diverse challenges – political, economic, legal and technical – face the continued development and deployment of geological storage of anthropogenic CO 2 . Among the technical challenges will be the satisfactory proof of storage site security and efficacy. Evidence from many past geotechnical projects has shown the investigations and analyses that are required to demonstrate safe and satisfactory performance will be site specific. This will hold for the geomechanical assessment of saline aquifer storage site integrity where, compared to depleted hydrocarbon fields, there will be no previous pressure response history or rock property characterization data available. The work presented was carried out as part of a project investigating the improvement in levels of confidence in all aspects of saline aquifer site selection and characterization that could be expected with increasing data availability and in-depth analysis. Attention focused on the geomechanical modelling and the rock mechanics data used to populate models of two storage sites in geological settings analogous to those where CO 2 storage might be considered. Coupled geomechanical models were developed from reservoir simulation models initially incorporating generic rock mechanical properties and then laboratory-derived site-specific properties. The models were run in various configurations to investigate the effect of changing the rock mechanical properties on the geomechanical response of the storage systems. Modelling results showed that the pressure response at one site due to low injectivity caused significant potential for fault reactivation. Increasing the number of injection wells, thereby reducing the individual rates needed to deliver the target capacity, reduced the injection pressures and ameliorated, but did not eliminate, this adverse response.

Predicting ground subsidence due to long term oil/gas production in a Niger Delta basin, Nigeria: implications for CO2 EOR and geosequestration

“…(Innovation and infrastructure), SDG 11 (Cities and communities) and SDG 13 (climate change) (Abija, 2021). CO 2 reservoirs occur naturally in subsurface geological formations demonstrating that it can be stored underground for millions of years (Olden, et al 2014). The immediate geomechanical risk associated with the technology is reservoir seal breach, fault leakage, secondary migration and induced seismicity all occasioned by fault reactivation at high injection pressures capable generating shear stresses exceeding the frictional strength of the crustal faults that compartmentalize the reservoirs under the in situ stress eld.…”

Coupled Flow Simulation and Geomechanical Modeling on CO<sub>2</sub> Storage in a Saline Aquifer

“…Fault will initiate when the then difference between the maximum and minimum principle stress become very large. The relationship among the three principle stresses was assumed as following [22]:…”

3D Field-Scale Geomechanical Modeling of Potential CO2 Storage Site Smeaheia, Offshore Norway

“…However, building a geomechanical model requires the integration of various parameters. For instance, the caprock and overburden section are mostly ignored during the acquisition of relevant databases compared to the reservoir interval and use simple assumptions in the modeling workflow [21][22][23][24][25][26][27][28][29][30]. Irrespective of the data limitation, the effectiveness of 3D field-scale geomechanical modeling in rock deformation and failure has been proven and published by several authors for CO 2 injection and gas storage projects worldwide [21,22,[24][25][26][27][28][29].…”

“…For instance, the caprock and overburden section are mostly ignored during the acquisition of relevant databases compared to the reservoir interval and use simple assumptions in the modeling workflow [21][22][23][24][25][26][27][28][29][30]. Irrespective of the data limitation, the effectiveness of 3D field-scale geomechanical modeling in rock deformation and failure has been proven and published by several authors for CO 2 injection and gas storage projects worldwide [21,22,[24][25][26][27][28][29]. However, the conventional 1D well property-point-interpolation method and a simple assumption in the missing interval (mainly caprock and overburden sections) have been considered in most of the models.…”