摘要
压裂改造体积估算的精度直接制约着产能预测的精度,并进一步影响后续非常规储层开发策略的制定,因此预测有效压裂体积预测的精度越高意义越大。目前工程压裂改造体积的预测主要通过微地震监测事件点计算波及体积,但该方法受主观人为因素影响较大,体积误差达一个甚至数个数量级,因而产能预测精度低。为此,采用非结构化四面体网络,对有效微地震事件点按破裂树模式得到的压裂缝网络进行表征和描述,然后建立离散缝网地质模型。在此基础上,对压裂井进行快速衰竭开发数值模拟,得到全场压力分布,该分布一般为漏斗型,根据压力漏斗边缘确定改造区临界压力,然后找出压力小于该临界压力值的四面体网格,将这些网格对应的体积相加得到参与渗流的裂缝体积,即有效压裂体积。该方法在某平台3口压裂井的实际应用结果表明:基于该压裂体积经济极限预测的产能与单井实际生产数据拟合得到的经济极限累产气结果吻合度高,表明利用该方法预测得到的有效压裂体积精度较高。
The accuracy of fracturing volume directly restricts the accuracy of productivity prediction and affects the development of unconventional reservoirs.Therefore,the high-precision effective fracturing volume must be predicted.Currently,the engineering fracturing volume is primarily calculated based on microseismic monitoring event points,which are significantly affected by human subjective factors.The volume error is one or several orders of magnitude,and the productivity prediction accuracy is low.Hence,an unstructured tetrahedron network is used to characterize the effective microseismic event points using the fracture tree model,and a discrete fracture network is established.Subsequently,a rapid numerical simulation of the depletion development of fractured wells is performed to obtain the pressure distribution in the entire field,generally known as the funnel-type distribution.Based on the edge of the pressure funnel,the critical pressure PC of the transformation area is determined,followed by tetrahedral grids with a pressure lower than the above-mentioned critical value.The volumes of these grids are summed to obtain the effective fracture volume.The practical application results of three fractured wells on a platform are analyzed.The production capacity predicted based on the economic limit of the fracturing volume is consistent with the actual production data of a single well,proving that the method can yield the effective fracturing volume with high accuracy.
作者
丁圣
李飞
杨尚锋
杨小慧
DING Sheng;LI Fei;YANG Shangfeng;YANG Xiaohui(Sinopec Geophysical Research Institute,Nanjing 211103,China)
出处
《石油物探》
CSCD
北大核心
2022年第4期705-711,共7页
Geophysical Prospecting For Petroleum
基金
国家科技重大专项(2017ZX05036-005-010)资助。
关键词
微地震事件
层状离散缝网模型
有效压裂体积
临界压力
压力衰竭模拟
产能预测
microseismic event
layered discrete mesh model
effective fracturing volume
critical pressure
pressure failure simulation
productivity prediction
