Research on Energy Recharge Technology of Tight Oil Reservoir Based on CMG Numerical Simulation

Due to the characteristics of nano-scale pore size and strong reservoir heterogeneity in tight reservoirs, problems such as difficulty in replenishing formation energy and low calibrated recovery factor are commonly encountered during their development. In this paper, aiming at the above-mentioned problems, the research on efficient energy replenishment methods for tight reservoirs is systematically carried out by using reservoir numerical simulation as a technical means. The comparative analysis of the production of oil wells in tight reservoirs and development effects under different injection media (CO2, water, N2, slickwater) and injection methods (continuous water injection, CO2 - WAG, N2 - WAG, slickwater huff and puff) under the conditions of vertical wells and horizontal wells is mainly carried out. The results show that for vertical wells, the effect of CO2 - WAG is the best. Its gas injection production is significantly higher than that of water injection and slickwater huff and puff, and it is less affected by the production cycle. The early production of N2 - WAG is slightly better, but it decreases rapidly in the middle and late stages. For horizontal wells, slickwater huff and puff promotes the flow of remaining oil through low-viscosity fluid, achieving an oil increment of 0.18–0.28 ten thousand tons per well. Refracturing realizes an oil increment of 0.62–0.63 ten thousand tons per well by reconstructing the fracture structure. These methods can effectively release the remaining oil in tight oil reservoirs and greatly improve the development benefits of the reservoirs.