气井水力压裂有效缝长评估及影响因素研究

为了准确确定气井压后有效缝长及其影响因素，提高川西须家河气藏水力压裂针对性，对于具备生产历史拟合条件的气井，利用数值模拟软件进行了生产历史拟合获得有效水力裂缝缝长，与采用净压力拟合方法获得的水力裂缝支撑缝长进行对比和拟合，获得了有效缝长和支撑缝长的关系式，计算了川西须家河储层单井压后有效缝长；采用灰色关联分析理论分析了各个参数对有效缝长的影响程度和对压裂设计的启示。结果表明：压后有效缝长与支撑缝长具有较强相关性(Le=00584 Lp1359 3)，有效缝长明显比支撑缝长短；施工参数(特别是用液量)是影响须家河储层有效缝长的关键，而储层和隔层间应力差则是影响有效缝长的重要客观因素。该研究方法为水力压裂压后评估和提高压裂设计水平提供了较好的借鉴。

Study on Evaluation of Effective Hydraulic Fracture Length of Gas Well and Its Influencing Factors

In order to accurately determine effective hydraulic fracture length and its influencing factors of gas well,to improve the pertinence of hydraulic fracturing in Xujiahe Reservoir, West Sichuan, the relationship between effective length obtained from the gas wells and propped length obtained from net pressure fitting is determined.The degree of the parameters influence on effective length is analysed by grey correlation analysis theory, and its implication to fracturing design is also analysed.Calculation results showed that there is a noticeable correlativity between effective length and propped length (Le=0.0584 Lp13593), and effective length is shorter obviously than propped length; construction parameters (especially fracturing fluid volume) is the primary determinant of effective length in Xujiahe Reservoir,and the stress difference between barrier and interbed is the key objective factor.This research provides a reference for post fracturing evaluation and improvement of hydraulic fracturing design level.