Numerical investigation of refracturing with/without temporarily plugging diverters in tight reservoirs  

作　　者：Xiao-Hua Wang Feng-Shou Zhang Zi-Rui Yin Ding-Wei Weng Hong-Bo Liang Jun-Ping Zhou Bin Xu 

机构地区：[1]Shale Gas Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu,610051,Sichuan,China [2]Key Laboratory of Geotechnical&Underground Engineering of Ministry of Education,Tongji University,Shanghai,200092,China [3]Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai,200092,China [4]Research Institute of Petroleum Exploration and Development,PetroChina,Langfang,065007,Hebei,China [5]State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing,400044,China [6]School of Resources and Safety Engineering,Chongqing University,Chongqing,400044,China [7]Origin Geomechanics Inc.,Calgary,T3H0X6,Canada [8]Department of Civil Engineering,University of Calgary,Calgary,T2N1N4,Canada

出　　处：《Petroleum Science》2022年第5期2210-2226,共17页石油科学（英文版）

基　　金：funded by the National Natural Science Foundation of China(41772286,42077247);the Fundamental Research Funds for the Central Universities;Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(Z020009)。

摘　　要：Refracturing is an importa nt technique to tap the potential of reservoirs and boost production in depleted oil and gas fields.However,fracture propagation during refracturing,including both conventional refracturing and temporary-plugging refracturing remains poorly understood,especially for cases with non-uniform distribution of formation pressure due to long-term oil production and water injection.Therefore,taking pilot tests of refracturing with sidetracking horizontal wells in tight reservoirs in the Changqing Oilfield,China as an example,we establish a three-dimensional numerical model of conventional refracturing and a numerical model of temporary-plugging refracturing based on the discrete lattice method.Non-uniform distributions of formation pressure are imported in these models.We discuss the effects of key operating parameters such as injection rate,cluster spacing,and number of clusters on the propagation of multi-cluster fractures for conventional refracturing.For temporaryplugging refracturing,we examine the impacts of controlling factors such as the timing and number of temporary plugging on fracture propagation.In addition,we analyze a field case of temporaryplugging refracturing using well P3 in the Changqing Oilfield.The results show that fractures during re fracturing tend to propagate preferentially and dominantly in the depleted areas.Improved stimulation effect can be obtained with an optimal injection rate and a critical cluster spacing.The proposed model of temporary-plugging refracturing can well describe the temporary plugging of dominant existingfractures and the creation of new-fractures after fracturing fluid is forced to divert into other clusters from previous dominant clusters.Multiple temporary plugging can improve the balanced propagation of multi-cluster fractures and obtain the maximum fracture area.The established numerical model and research results provide theoretical guidance for the design and optimization of key operating parameters for refracturing,especially for tempora

关 键 词：Tight reservoir Hydraulic fracturing Temporary plugging Discrete lattice method Multi-cluster fracturing 

分 类 号：TE357[石油与天然气工程—油气田开发工程]