泾河油田致密低渗油藏水平井重复压裂技术

Horizontal well re-fracturing technology in tight and low permeability reservoir 
of Jinghe Oilfield

张永春

中国石化华北油气分公司石油工程技术研究院，河南 郑州 450007 成都理工大学能源学院，四川 成都 610059

Research Institute of Petroleum Engineering and Technology, North China Oil and Gas Company, SINOPEC, Zhengzhou 450007, China College of Energy, Chengdu University of Technology, Chengdu 610059, China

泾河油田致密低渗油藏受储层物性差、非均质性强，以及注水驱替系统难以建立等因素的影响，部分水平井产量递减快、采收率低。重复压裂面临工艺优选、新缝开启与老缝延伸、储层保护等难点。文中研究了初次改造不充分的水平井油藏压力和剩余油分布特征，利用重复压裂与补充地层能量相结合的水平井储能压裂技术，优化重复压裂施工参数，优选压裂液体系和配套压裂管柱，形成增大储层改造体积、补充地层能量、提高油水置换效率的一体化水平井重复压裂技术。在泾河油田致密低渗油藏X井开展重复压裂，优化重复压裂6段16簇，水平段加砂强度和进液强度分别为1.3，15.4 m3/m，是初次压裂的4.2倍和9.1倍，有效改造体积为1.76×106 m3。此项技术可为同类致密低渗油藏重复压裂改造提供参考。

The tight and low permeability reservoir in Jinghe oilfield is affected by poor reservoir physical properties, strong heterogeneity and difficulty in establishing water injection displacement system, resulting in rapid production decline of some horizontal wells and low recovery rate. Re-fracturing faces difficulties such as process optimization, new fracture opening and old fracture extension, reservoir protection and so on. This paper studies the reservoir pressure and residual oil distribution characteristics of insufficient horizontal wells in the initial reconstruction. Using the technology of energy storage fracturing for horizontal wells combining re-fracturing and formation energy supplement, the re-fracturing operation parameters, fracturing fluid system and supporting fracturing string were optimized, and the integrated horizontal well re-fracturing technology was formed to increase stimulated reservoir volume, supply formation energy and enhance the oil-water displacement efficiency. In tight and low permeability reservoir of Jinghe Oilfield, well X was carried out re-fracturing, and 6 sections and 16 clusters were optimized. The sand adding strength of the horizontal section fluid and injection strength were 1.3 m3/m and 15.4 m3/m respectively, which were 4.2 times and 9.1 times of the initial fracturing, and the effective stimulated reservoir volume was 1.76×106 m3. This technology can provide reference for re-fracturing in similar tight and low permeability reservoirs.

10.6056/dkyqt202105025