Abstract
Hydraulic fracturing, a well-established technique in the oil and gas industry, has gained significant attention as a potential method to improve the short- and long-term efficiency of the Carbon Capture, Utilization, and Storage (CCUS) process. Most of the scoping studies on CCUS have centered on the reservoir aspects, such as storage and CO2 movement. Very little has been done evaluating what the fracture designs might look like in this process.
This paper presents a review of the application of hydraulic fracturing in CCUS projects, examining its technical feasibility, fluids, sustaining agents, wellbore orientation, and fracture orientation considerations required to assure its technical and economic success. It will consider rock properties, depleted oil or gas reservoirs conditions, or deep saline aquifers horizons and compressed CO2 supply at the storage site; simulations have been performed using primarily super critical CO2 (scCO2) and conventional fluids to perform the hydraulic fracturing. In addition to the sCO2 usage and proppants required to tail the generated fractures; the wellbore orientation effect in reference to the stress plane is also considered in the paper.
Finally the short- and long-term benefit of the hydraulic fracturing will be evaluated by simulating the CO2 injection behavior.
The review encompasses an analysis of the various key stages involved in CCUS hydraulic fracturing process, starting from the review of rock properties, wellbore orientation, perforation strategy, selection of suitable fluid and propping agents for efficient and safe stimulation of a well candidate. The potential benefits of the proper hydraulic fracturing process implementation will be translated in an enhanced storage capacity and improved injectivity.
The extensive simulations considering the sCO2 as the primary fluid system for fracturing purposes, combined with the wellbore orientation and other parameters will show the direct benefit of the combinations of the hydraulic fracturing and the CCUS processes, including:
The use of sCO2 and proppants for hydraulic fracturing purposes in CCUS
The influence of the wellbore and hydraulic fracture orientation in the success of the CCUS process
The paper aims to explore the potential of CCUS in conjunction with hydraulic fracturing to increase the efficiency of CO2 disposal and analyze methods to maximize its effectiveness. It will be beneficial for those contemplating CCUS, complementing other CCUS evaluations to provide a more complete picture of the feasibility as well as technical hurdles that must be overcome to implement this concept.
