A Novel Method to Enhance Oil Recovery by Inter-Fracture Injection and Production Through the Same Multi-Fractured Horizontal Well

Abstract

Conventional enhanced oil recovery (EOR) approaches are inefficient in the unconventional reservoirs. This paper provides a novel approach to enhance oil recovery from unconventional oil reservoirs through synchronous inter-fracture injection and production (SiFIP) and asynchronous inter-fracture injection and production (AiFIP). The compartmental embedded discrete fracture model (cEDFM) is introduced to simulate complex fracture geometries to quantitatively evaluate the performance of SiFIP and AiFIP. EOR performances using multiple producing methods are investigated (i.e., depletion, fluid flood, fluid Huff and Puff, SiFIP, AiFIP. Higher cumulative oil production rates can be achieved by AiFIP and SiFIP. AiFIP yields the highest oil recovery factor, two times higher than depletion. Compared with SiFIP, AiFIP may be a preferred method when CO2/water resources are short. The impacts of fracture and injection parameters on oil production are discussed. The feasible well completions for AiFIP and SiFIP are provided. AiFIP (CO2) achieves the best EOR performance among different producing methods. This paper demonstrates the feasibility of SiFIP and AiFIP to improve oil recovery. The proposed methods improve flooding performance by transforming fluid injection among wells to among hydraulic fractures from the same Multi-fractured horizontal well (MFHW), which is a promising EOR approach in unconventional oil reservoirs. The proposed EOR method (AiFIP-CO2) can improve the oil recovery, and mitigate the emission of CO2 as well as reduce the waste of water resources.

Study of the Enhanced Oil Recovery Mechanism and Remaining Oil State of Heavy Oil after Viscosity-Reducer-Assisted CO2 Foam Flooding: 2D Microvisualization Experimental Case

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Establishment of Stability Evaluation Criteria for the Oil–Gas Interface during Gas-Cap Gravity Flooding in Oil Reservoirs with Strong Edge-Water Drive

“…Meszaros et al found that up to 70% of the oil reservoirs produced by gravity-stabilized gas flooding was by N 2 injection . The study found that gas-assisted gravity drainage (GAGD) technology can improve sweep efficiency and oil displacement efficiency and can effectively improve oil recovery compared with conventional gas flooding. − The results showed that GAGD technology could improve the recovery rate by 100% in laboratory experimental tests and 87–95% in field application…”

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