一种水平井压裂裂缝定量描述方法  

A quantitative description method for horizontal well fracture

作　　者：刘长印[1] LIU Changyin(Oil Production Institute of Sinopec Petroleum Exploration and Development Research Institute·Key Laboratory of Marine Oil and Gas Reservoir of Sinopec,Beijing 100083,China)

机构地区：[1]中国石化石油勘探开发研究院采油所·中国石油化工集团公司海相油气藏开发重点实验室,北京100083

出　　处：《油气井测试》2020年第5期1-5,共5页Well Testing

基　　金：国家科技重大专项“大型油气田及煤层气开发”中课题“中西部地区碎屑岩领域勘探关键技术”(2016ZX05002-005)。

摘　　要：针对水平井压裂后裂缝形态及复杂程度缺乏有效评价手段的问题,研究了一种水平井压裂裂缝复杂程度定量评价的方法。利用压降数据计算得到G函数曲线图版,拟合时叠加导数曲线在裂缝闭合点前呈现“上凸”,表明具有裂缝发育的特征。根据叠加导数曲线“上凸”波动大小和次数将G函数曲线分为四种曲线类型并进行量化,依据其反应的裂缝复杂程度,分别赋予不同的权重值;加入水平井压裂总段数、每种类型裂缝段数,计算水平井压裂裂缝复杂程度评价系数。7口井计算应用,评价系数越高,压后效果越好,通过该值与压后产量交汇分析得出两者的相关系数达0.9239,证明了该方法具有一定的可行性,实现了裂缝复杂程度评价定量化,为压裂效果评价提供了理论依据。A quantitative method to evaluate the fracture complexity of horizontal wells has been studied in view of the problem that there is no effective method to evaluate the fracture geometry and complexity for horizontal wells after fracturing.The graph of G function curve was calculated by using the pressure drop data.When matching,if the superposed derivative curve is“convex”before the fracture closure point,it indicates that the formation has the characteristics of fracture development.The G function curve is divided into four types and quantified according to the amplitude and frequency of“convex”fluctuation on the superposed derivative curve.Different weight values will be given to each type according to the complexity reflected.The evaluation coefficient of fracture complexity of horizontal well is calculated by adding the total number of fracture sections of horizontal well and the number of fracture sections of each type.The application of 7 wells shows that the higher the evaluation coefficient is,the better the effect after fracturing is.Through the intersection analysis of the value and the output after fracturing,the correlation coefficient of the two is 0.9239,which proves that the method is feasible to a certain extent,realizes the quantitative evaluation of fracture complexity,and provides a theoretical basis for the evaluation of fracturing effect.

关 键 词：水平井 压裂 裂缝形态 裂缝复杂程度 定量评价 评价系数 G函数曲线 

分 类 号：TE357[石油与天然气工程—油气田开发工程]