裂缝变缝宽形态对压裂井长期产能的影响  

Influence of varying fracture width on fractured well's long-term productivity

作　　者：郭建春[1] 刘恒[2] 曾凡辉[2] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500 [2]西南石油大学石油与天然气工程学院,四川成都610500

出　　处：《中国石油大学学报（自然科学版）》2015年第1期111-115,共5页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(51074138);四川省青年科技创新研究团队专项(2011JTD0018)

摘　　要：基于流体扩散理论和势叠加原理,采用半解析方法研究盒形封闭边界下垂直裂缝压裂井的油藏渗流和裂缝流动过程并建立相应数学模型,对压裂井的不稳定产能进行预测,并对裂缝非均匀流入剖面进行模拟。结果表明:生产初期,流入量集中于近井筒附近的裂缝,进入拟稳态阶段后流入量集中于裂缝趾部;裂缝沿缝长变窄的形态在生产初期不影响产能,由于流体流入裂缝的位置向裂缝趾部集中,裂缝趾部越窄,产量越低;拟稳态阶段时,等缝宽与变缝宽裂缝间的累积产量差距加大,产量差距主要集中于裂缝后1/3区域,该区域贡献了裂缝约一半的累积产量。加宽裂缝趾部缝宽能提高和保持压裂井在拟稳态阶段的产量,对压裂井的稳产、高产具有意义。The flow behavior in reservoir matrix and fractures for oil production through a fractured vertical well was investigated based on fluid diffusion theory and potential superposition principles. A semi-analytical model was established,which can be used to predict well＇s transient productivity considering uneven inflow profiles along the fracture. The results show that the early production is mainly from the panels close to the wellbore,and then from the far end of the fracture in later time.The wedge-shape of the fracture has little effect on the initial productivity,but when the fluid inflow toward the end of the fracture,the narrower the fracture tip,the lower the production is observed. At a pseudo-steady state,the difference of cumulative production between a constant width fracture and that of wedge-shaped can be significantly large,which mainly appears at the 1 /3 end part of the fracture,but accounts for a half of the total production. Widening the width of the fracture tip can improve the productivity of fractured wells at pseudo-steady state.

关 键 词：油藏 流体扩散 不稳定产能 变缝宽 流入剖面 压裂井 

分 类 号：TE355.6[石油与天然气工程—油气田开发工程]