Study on Enhanced Oil Recovery Technology of Tight Reservoir Modified in Highly Deviated Well: A Case Study of the L183 Area in the Huaqing Oilfield Ordos Basin, China

Chang 6 sandstone reservoir in Huaqing oilfield is a typical tight reservoir. The whole reservoir presents the characteristics of obvious non Darcy seepage, widespread development of natural fractures, large proportion of low production and low efficiency wells, and low production of single wells developed by conventional vertical wells. Based on the mechanism of highly deviated wells improving oil production rate, aiming at the problems of low recovery degree and fracture development induced by water injection during the development of tight reservoirs, this paper verifies the feasibility and superiority of highly deviated wells in tight reservoirs through indoor numerical simulation and field actual effect evaluation. The research results indicate that: (1) The highly deviated wells in the study area adopt advanced fine layered water injection development method, and the regional formation pressure is maintained at a level of over 120%. By utilizing the role of closed well infiltration and displacement, the seepage range is increased and the oil recovery rate is significantly improved. (2) Through numerical simulation combined with actual field test results, it has been proven that the concept of reducing the number of fracturing sections by combining cost control in highly inclined well areas, and the optimal perforation control degree is achieved at 10–20 m per well, with a reasonable flow to saturation ratio of less than 1.0, can maximize the benefits. It is concluded that the development of highly deviated wells in the L183 area of Huaqing oilfield provides strong support for the optimization design of fracturing parameters of thick reservoirs with tight interlayer, and provides theoretical guidance and technical support for their field application.