基于最小体积封闭椭球算法的多段水力压裂改造体积估算  

Estimation of the Stimulated Reservoir Volume of Multi-stage Hydraulic Fracturing in Minimum Volume Enolosing Ellipsoid Algorithm

作　　者：王旭林 桂志先[1] 王鹏[1] 易娟子 WANG Xu-lin;GUI Zhi-xian;WANG Peng;YI Juan-zi(Hubei Cooperative Innovation Center of Unconventional Oil and Gas,Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,Wuhan 430100,China;Chongqing Gas Field,PetroChina Southwest Oil and Gas Field Company,Chongqing 400021,China)

机构地区：[1]长江大学非常规油气湖北省协同创新中心,油气资源与勘探技术教育部重点实验室,武汉430100 [2]中国石油天然气股份有限公司西南油气田分公司重庆气矿,重庆400021

出　　处：《科学技术与工程》2020年第1期48-53,共6页Science Technology and Engineering

基　　金：国家自然科学基金(41604099);油气资源与勘探技术教育部重点实验室(长江大学)开发基金(K2018-01)

摘　　要：压裂改造体积(stimulated reservoir volume,SRV)是页岩油气开发的重要参数之一。为了解决在多段水力压裂作业过程中,不同压裂井段间压裂改造体积彼此重叠、单段压裂可能会形成复杂裂缝网络的问题。提出了基于最小体积封闭椭球算法(minimum volume enclosing ellipsoid,MVEE)的SRV估计算法。该算法首先使用DBSCAN(density based spatial clustering of applications with noise)算法消除微震事件的异常定位结果并将复杂微震事件展布进行分组处理,转化为多组分布特征相对简单的微震事件,然后使用最小体积封闭椭球算法(minimum volume enclosing ellipsoid,MVEE)估算单段压裂改造体积,最后基于椭球体参数,利用仿射变换消除多段压裂改造体积的重叠区域和单段压裂的不同分组间的重叠区域,并最终估算出整体压裂改造体积。使用两组实测水力压裂微震监测数据对本文方法进行了验证,结果表明:提出的方法对于多段压裂裂缝网络重叠和单段压裂可能形成复杂裂缝网络两类情况下的压裂改造体积的估算具有较好的效果。Stimulated reservoir volume(SRV)is one of the important parameters in shale oil and gas industries.In practice,there are several problems in SRV estimation of multiple-stage hydraulic fracturing,such as hydraulic fracturing networks overlap among different stages,and complex hydraulic fracturing network in the single stage.To solve these problems,an SRV estimation was proposed based on minimum volume enclosing ellipsoid(MVEE)algorithm.First,density based spatial clustering of applications with noise(DBSCAN)was used to eliminate abnormal location results of microseismic events and convert complex distribution of microseismic events into multiple simple distribution groups.Then,MVEE was applied to calculate the SRV of each fracturing stage.Last,based on the parameters of each ellipsoid of every hydraulic stage,the overlap volumes of the SRVs could be calculated by using affine transformation among multiple fracturing stages or multiple groups of single fracturing stage.Two groups of field data were used to evaluate the validity of the proposed method.The processing results confirm the proposed method,indicating good performance of the proposed method.

关 键 词：水力压裂 微震监测 压裂改造体积 最小体积封闭椭球 

分 类 号：P315[天文地球—地震学]