致密油藏储层水平井渗吸增能吞吐技术研究与应用

Research and application of imbibition and energy stimulation huff & puff technology for horizontal wells in tight oil reservoir

针对大庆油田垣平1区块水平井缝网压裂后产量递减快的问题,提出了对致密油藏储层水平井采用渗吸增能吞吐技术的研究。以高分子化学、油层物理学和石油地质学等为理论指导,以化学分析和仪器检测等为技术手段,结合试验区地质条件和油藏特征,开展了渗吸剂配方体系的筛选和优化,探索出一套适用于试验区提高缝网压裂井采收率的配方体系。性能评价试验表明:配方体系的界面张力、破乳率、破碎率和防膨率分别达到0.0088mN/m、 91%、 1.342%和80.22%,能够满足试验区现场试验要求;在精细可靠的地质模型基础上,结合室内物理模拟实验成果,运用数值模拟技术,确定出垣平1-X井渗吸剂增能吞吐的注入量、注入速度和焖井时间分别为10000m^3、 100m^3/d、 60天;对该井进行了现场试验,措施后生产255天,累计增油达814.31t,验证了此技术的可行性。该技术为解决致密油藏水平井缝网压裂后产量递减快的问题提供了可行的解决方案,具有一定的借鉴意义。

Research on imbibition and energy stimulation huff & puff technology for horizontal wells in tight oil reservoir is put forward to solve the problems of rapid production decline after fracture network fracturing for horizontal wells in Yuanping Block 1 of Daqing Oilfield.The selection and optimization of the formula system for imbibition agent have been carried out by technical means of chemical analysis and instrument detection in combination with geological conditions and reservoir characteristics of the pilot area,as well as under the theoretical guidance of polymer chemistry,reservoir physics and petroleum geology.The formula system for increasing recovery efficiency of fracture network fracturing wells that applied to pilot area was explored.The performance evaluation test showed that the interfacial tension,demulsification rate,crushing ratio and anti-swelling rate of the formula system had been reached 0.0088mN/m,91%,1.342% and 80.22% respectively,which could meet requirements of field tests in the pilot area.On the basis of fine and reliable geological models and in combination with experimental results of indoor physical simulation,the injection volume,injection speed of imbibition agent and energy stimulation huff&puff and soak time in Yuanping 1-X well were determined to be 10,000m^3,100m^3/d and 60 days respectively by using the numerical simulation technology.The field test of the well was carried out,and the accumulated increase of oil production reached 814.31t for 255 days of production after treatment,which verified the feasibility of the technology.The technology provides a feasible solution for solving the problems of rapid production decline after fracture network fracturing for horizontal wells in tight oil reservoir with certain reference value.