Publications

Integrating subsurface model for carbon dioxide (CO2) sequestration with the surface facility model is very important to ensure long term deliverability and storage of CO2 to the subsurface formation. This paper aims to develop an automated integrated workflow to generate a niche CO2 sequestration strategy by optimizing surface facility and well operational designs while managing subsurface risks with a case study in a saline aquifer located in the Norwegian sector of the North Sea. A high-resolution simulation model coupled with geomechanics is fully implicitly integrated with wells and surface network facility to transport CO2 from the source and injection of the CO2 into a large subsurface formation. A unified PVT system of the CO2, which contains impurities, is modeled to characterize fluid physics in the subsurface, well and pipeline models. An integrated surface-to-subsurface network workflow is constructed to investigate the effects of different boundary conditions at the source, compressor design, pipeline diameter, thermal conductivity, fluid components, injection wellbore design, sensitivity with respect to CO2 injectivity, storage capacity, and potential geomechanical risks. The integrated pipeline and wellbore system enables injection conditions to be predicted from the CO2 source to the bottom hole. Hundreds of scenarios were generated incorporating well and surface facility uncertainties. Uncertainty quantification which is performed based on Monte Carlo and Latin Hypercube designs help in understanding major issues, i.e. storage mechanisms, CO2 plume distribution, and processes that could potentially cause CO2 to leak out of the target formation and rock failure. Based on multi-realization scenarios, the CO2 can be injected for up to one million tonnes per year from a well. With the optimum operational design, the system could maintain the injection rate for all injectors until the end of injection period while ensuring CO2 plume distribution stay below the caprock.