摘要
致密油藏水平井多段压裂施工中存在应力敏感导致裂缝导流能力变化的特征,开展水力裂缝应力敏感性研究对于水平井连续监测压力数据分析方法至关重要。因此基于不稳定渗流理论,考虑裂缝内部应力敏感效应,建立多段压裂水平井试井分析模型。通过定义裂缝拟压力方式,实现拟压力与井底实际压力之间转化,并绘制试井理论曲线。结合叠加原理,模拟压裂注入、焖井及返排阶段压力变化曲线,分析渗透率模量对压力变化曲线影响。通过考虑裂缝内应力敏感效应,间接表征了裂缝变导流能力性质。研究表明,渗透率模量越大,试井曲线后期上翘越严重,压后地层恢复稳定所需时间越短,返排阶段压力下降越快。该方法为致密油藏水平井压裂过程中连续压力监测数据解释提供了理论依据。
During the multi-stage fracturing of horizontal wells in tight oil reservoirs,stress sensitivity may significantly alter fracture conductivity,therefore,investigating the stress-sensitive characteristics of hydraulic fractures is crucial for analyzing the continuously monitored pressure data from these wells.Accordingly,based on the transient flow theory and explicitly incorporating the stress-sensitive effect within the fractures,a well-testing analysis model for multi-stage fractured horizontal wells was established.By defining a fracture pseudo-pressure,a transformation between the pseudo-pressure and the actual bottom-hole pressure was achieved,and then the well testing curves were plotted.Utilizing the superposition principle,the model simulated pressure evolution across injection,soaking,and flowback stages,thereby analyzing the impact of the permeability modulus on these pressure profiles.This approach indirectly characterizes the phenomenon of variable fracture conductivity by accounting for the intra-fracture stress sensitivity.The findings demonstrate that a larger permeability modulus leads to a more pronounced upward deviation in the late-time period of the well testing curve,a shorter time for post-fracturing formation stabilization,and a faster pressure decline during the flowback stage.The proposed approach provides a theoretical foundation for interpreting continuously monitored pressure data during the fracturing of horizontal wells in tight oil reservoirs.
作者
徐凤兰
许亚东
陈东升
李俊
王永军
邵振鹏
XU Fenglan;XU Yadong;CHEN Dongsheng;LI Jun;WANG Yongjun;SHAO Zhenpeng(Huabei Well Testing Branch,China National Logging Corporation,Langfang,Hebei 065007,China;Downhole Services Company,CNPC Bohai Drilling Engineering Company Limited,Renqiu,Hebei 062552,China)
出处
《油气井测试》
2025年第5期56-62,共7页
Well Testing
基金
中国石油渤海钻探工程有限公司科技研发类项目“测试解释评价关键技术研究”(2023ZD01F-03)。
关键词
致密油藏
水平井压裂
应力敏感
渗透率模量
变导流
压力数据分析
连续监测
tight oil reservoir
horizontal well fracturing
stress sensitivity
permeability modulus
variable conductivity
pressure data analysis
continuous monitoring
