页岩油储层CO_(2)前置蓄能对压裂液返排效率影响规律  

Influence of Energy Storage of CO_(2) Pre-pad on Flowback Efficiency of Fracturing Fluid in Shale Oil Reservoirs

作　　者：鲁明晶 钱钦 钟安海 张潦源[1] 杨峰[1] 李敏[1] 罗明良[3] LU Ming-jing;QIAN Qin;ZHONG An-hai;ZHANG Liao-yuan;YANG Feng;LI Min;LUO Ming-liang(Petroleum Engineering Technology Research Institute of Shengli Oilfield,Sinopec,Dongying 257000,China;Postdoctoral Scientific Research Working Station of Shengli Oilfield,Sinopec,Dongying 257000,China;College of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石化胜利油田分公司石油工程技术研究院,东营257000 [2]中国石化胜利油田分公司博士后科研工作站,东营257000 [3]中国石油大学(华东)石油工程学院,青岛266580

出　　处：《科学技术与工程》2024年第30期12962-12970,共9页Science Technology and Engineering

基　　金：山东省自然科学基金(ZR2021QE260);中国博士后自然科学基金(2021M702304)。

摘　　要：CO_(2)前置蓄能压裂具有增能效果好、返排速度快、储层伤害小等优势,是一种极具前景的储层改造措施。利用数值模拟方法考察了储层参数(毛细管压力、基质渗透率)和工程参数(焖井压力、焖井时间、返排速度和返排压力)对页岩油储层CO_(2)前置蓄能压裂返排效果的影响规律,分析了各参数对压裂液返排效率的影响机制。结果表明,储层渗透率和毛管力越低,压裂液返排阻力越大,返排率越低;渗透率对CO_(2)蓄能效果的影响更为显著,毛管力对压裂液返排速度的影响很小。工程因素主要通过对CO_(2)的有效蓄能和液体压裂液因渗吸、滤失等原因滞留来影响返排效果。优化的返排参数范围内,压裂液返排率提升超过5%,原油采收率提升超过7%。在该制度下CO_(2)前置蓄能不仅可以为储层提供充足的返排和生产动力,还可以提高孔隙动用范围,提高原油采收率。CO_(2) pre-pad fracturing is a very promising reservoir stimulation method,possessing the advantages of excellent energy enhancement,fast flowback,low formation damage.The influences of reservoir parameters such as capillary pressure and matrix permeability,and engineering parameters such as soaking pressure,soaking time,flowback rate and flowback pressure on the flowback efficiency of CO_(2) pre-pad fracturing in shale reservoirs were investigated using numerical simulation methods,and the influence mechanism of each parameter was analyzed.The results show that the lower the values of reservoir permeability and capillary force,the higher the fracturing fluid flowback resistance and the lower the flowback rate.The influence of permeability on the CO_(2) storage effect is more significant.The influence of capillary force on the fracturing fluid flowback rate is negligible.Engineering factors affect the effectiveness of fracturing fluid flowback primarily through the effective accumulation of CO_(2) energy and the retention of fracturing fluid due to leakage and filtration losses.The optimized range of parameters resulted in an increase in fracturing fluid flowback rate of more than 5%and an increase in recovery rate of more than 7%.Energy storage of CO_(2) pre-pad in this regime can not only provide sufficient energy for reservoir return and production,but also improve the range of pore mobilization and increase crude oil recovery.

关 键 词：液态CO_(2) 前置蓄能压裂 返排效率 数值模拟 页岩油储层 

分 类 号：TE357[石油与天然气工程—油气田开发工程]