基于管外光纤监测的页岩气水平井多簇压裂效果评价  

Evaluation of Multi-Cluster Fracturing Effects in Horizontal Shale Gas Wells Basedon Optic Fiber Monitoring Outside Casing

作　　者：何乐 朱炬辉 梁兴 赵智勇 管彬 安树杰 HE Le;ZHU Juhui;LIANG Xing;ZHAO Zhiyong;GUAN Bin;AN Shujie(Downhole Services Company,CNPC Chuanqing Drilling Engineering Company Limited,Chengdu,Sichuan,610051,China;PetroChina Zhejiang Oilfield Company,Hangzhou,Zhejiang,311100,China;Optical Science and Technology(Chengdu)Ltd.,Chengdu,Sichuan,610097,China)

机构地区：[1]中国石油集团川庆钻探工程有限公司井下作业公司,四川成都610051 [2]中国石油浙江油田分公司,浙江杭州311100 [3]中油奥博(成都)科技有限公司,四川成都610097

出　　处：《石油钻探技术》2024年第4期110-117,共8页Petroleum Drilling Techniques

基　　金：中国石油重大科技专项“井下光纤智能监测技术现场试验”(编号:2020F-44);中国石油集团油田技术服务有限公司科学研究与技术开发项目“页岩油气勘探开发关键技术研究与应用”课题4“页岩储层光纤智能监测与裂缝评价技术研究与应用”(编号:2023T-002-001)联合资助。

摘　　要：为了分析页岩气水平井分段压裂影响多簇进液的因素,采用套管外分布式光纤开展压裂过程实时监测。以昭通页岩气示范区龙马溪组页岩水平井压裂光纤实时监测数据为基础,结合压裂设计数据和压裂施工数据,开展了分段多簇压裂过程中典型压裂事件和分布式光纤声波传感(DAS)信号的联合分析。分析结果表明:压裂初期孔眼欠完善、近井扭曲严重,容易激发强DAS信号,随着孔眼冲蚀,DAS信号减弱;多簇间流量分配呈随机动态变化,影响多簇进液的均衡性,有效进液簇数量与施工泵压具有一定相关性;暂堵、停泵−再启泵等措施能够干预簇间流量分配,暂堵效果受裂缝实时状态、暂堵参数等多因素影响;段间窜通存在2种光纤DAS信号响应模式,可揭示管内和水泥环2种段间窜漏路径。光纤监测手段和综合分析方法对于深入认识水平井分段多簇压裂机理、指导压裂方案优化和压裂实时调控具有重要的参考价值。In order to analyze the factors affecting multi-cluster fluid injection during multi-stage fracturing of shale gas horizontal wells,real-time monitoring of the fracturing process was carried out using distributed optic fibers outside the casing.A joint analysis of typical fracturing events and distributed optic fiber acoustic sensing(DAS)signals during multi-stage multi-cluster fracturing process was carried out based on the real-time monitoring data of optic fiber during fracturing of horizontal shale well in the Longmaxi Formation of Zhaotong Shale Gas Demonstration Zone,combined with fracturing design and operation data.The analysis finds that at the initial stage of fracturing,the perforation is not perfect,and near well distortion is serious and easy to trigger strong DAS signals.With the perforation erosion,the DAS signal weakens.There is a random dynamic change in the flow distribution between multiple clusters,which affects the uniformity of multi-cluster fluid injection.The number of effective clusters with fluid injection is correlated with operation pressure.Precautions such as temporary blocking,and pump stopping and restarting can intervene in the flow distribution between clusters,and the temporary blocking effect is influenced by multiple factors such as real-time state of fractures and temporary blocking parameters.There are two optic fiber DAS signal response modes for inter-segment leakage,which can reveal the leakage paths inside the casing and cement sheath.The optic fiber monitoring method and comprehensive analysis method have important reference values for an in-depth understanding of the mechanism of multi-stage multi-cluster fracturing of horizontal wells,guiding fracturing scheme optimization and real-time fracturing adjustment.

关 键 词：分布式光纤 孔眼冲蚀 流量分配 暂堵转向 砂堵 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]