Multi-fracture growth behavior during TPDF in a horizontal well of multi-clustered perforations:An experimental research  

作　　者：Yu-Shi Zou Can Yang Shi-Cheng Zhang Xin-Fang Ma Yan-Chao Li Long-Qing Zou 

机构地区：[1]State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing,102249,China [2]Shale Gas E&D Project Department,CNPC Chuanqing Drilling Engineering Co.,Ltd.,Chengdu,610052,Sichuan,China

出　　处：《Petroleum Science》2024年第6期4230-4247,共18页石油科学(英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant No.51974332)。

摘　　要：Temporary plugging and diverting fracturing(TPDF),involving inner-fracture temporary plugging(IFTP)and inner-stage temporary plugging(ISTP),has been proposed as a widely applied technique in China,for promoting the uniform initiation and propagation of multi-clustered hydraulic fractures(HFs)in a horizontal well of the shale oil/gas reservoirs.However,how the key plugging parameters controlling the multi-fracture growth and the pumping pressure response during TPDF in shale with dense bedding planes(BPs)and natural fractures(NFs)is still unclear,which limits the optimization of TPDF scheme.In this paper,a series of TPDF simulation experiments within a stage of multi-cluster in a horizontal well were carried out on outcrops of Longmaxi Formation shale using a large-scale true tri-axial fracturing simulation system,combined with the acoustic emission(AE)monitor and computed tomography(CT)scanning techniques.Each experiment was divided into three stages,including the conventional fracturing(CF),IFTP and ISTP.Multi-fracture initiation and propagation behavior,and the dominant controlling parameters were examined,containing the particle sizes,concentration of temporary plugging agent(TPA),and cluster number.The results showed that the number of transverse HFs(THFs)and the overall complexity of fracture morphology increase with the increase in TPA concentration and perforation cluster number.Obviously,the required concentration of TPA is positively correlated with the cluster number.Higher peak values and continuous fluctuations of pumping pressure during TPDF may indicate the creation of diversion fractures.The creation of standard THFs during CF is favorable to the creation of diversion fractures during TPDF.Moreover,the activation of BPs nearby the wellbore during CF is unfavorable to the subsequent pressure buildup during TPDF,resulting in poor plugging and diverting effect.Notably,under the strike-slip fault stress regime,the diversion of THFs is not likely during IFTP,which is similar as the results of ISTP to in

关 键 词：Shale Temporary plugging and diverting fracturing Bedding planes Natural fractures Multiple fractures 

分 类 号：TE243[石油与天然气工程—油气井工程]