Improving Oil Recovery Through Fracture Injection and Production of Multiple Fractured Horizontal Wells

Abstract

Well production rates decline quickly in the tight reservoirs, and enhanced oil recovery (EOR) is needed to increase productivity. Conventional flooding from adjacent wells are inefficient in the tight formations, and Huff-n-Puff also fails to achieve the expected productivity. This paper investigates the feasibility of inter-fracture injection and production (IFIP) method to increase oil production rates of horizontal wells. Three multi-fractured horizontal wells (MFHWs) are included in a cluster well. The fractures with even and odd indexes are assigned to be injection fractures (IFs) and recovery fractures (RFs). The injection/production schedule includes synchronous inter-fracture injection and production (s-IFIP) and asynchronous inter-fracture injection and production (a-IFIP). The production performance of three MFHWs are compared by using four different recovery approaches based on numerical simulation. Although the number of RFs is reduced by about 50% for s-IFIP and a-IFIP, they achieve much higher oil rates than depletion and CO₂ Huff-n-Puff. Sensitivity analysis is performed to investigate the impact of parameters on the IFIP. The spacing between IFs and RFs, CO₂ injection rates, and connectivity of fracture networks affect oil production significantly, followed by length of RFs, well spacing among MFHWs and length of IFs. The suggested well completion scheme for the IFIP methods is presented. This work discusses the ability of IFIP method in enhancing oil production of MFHWs.