An unequal fracturing stage spacing optimization model for hydraulic fracturing that considers cementing interface integrity  

作　　者：Xu Han Fu-Ping Feng Xiao-Chuan Zhang Jing Cao Jun Zhang Yu Suo Yan Yan Mao-Sen Yan 

机构地区：[1]Department of Petroleum Engineering,Northeast Petroleum University,Daqing,163318,Heilongjiang,China [2]Daqing Oil Field Limited-Liability Company,Daqing,163453,Heilongjiang,China [3]Tubular Goods Research Institute of CNPC,Xi’an,710000,Shaanxi,China

出　　处：《Petroleum Science》2023年第4期2165-2186,共22页石油科学（英文版）

基　　金：This work was supported by the Natural Science Foundation of Heilongjiang Province of China(YQ2021E005);the National Natural Science Foundation of China(No.51774094);the Youth Fund Project of National Natural Science Foundation of China(52004065);the Heilongjiang Natural Science Foundation Project(excellent youth project)(YQ2021E006);"Reveal the top"Science and Technology Project of Heilongjiang Province(2021ZZ10-04).

摘　　要：Determining reasonable fracturing stage spacing is the key to horizontal well fracturing.Different from traditional stage spacing optimization methods based on the principle of maximum stimulated reservoir volume,in this paper,by considering the integrity of the wellbore interface,a fracture propagation model was established based on displacement discontinuity method and the competition mechanism of multifracture joint expansion,leading to the proposal of an unequal stage spacing optimization model.The results show that in the first stage,the interfacial fractures spread symmetrically along the axis of the central point during that stage,while in the second and subsequent stages,the interfacial fractures of each cluster extend asymmetrically along the left and right sides.There are two kinds of interface connectivity behaviour:in one,the existing fractures first extend and connect within the stage,and in the other,the fractures first extend in the direction close to the previous stage,with the specific behaviour depending on the combined effect of stress shadow and flow competition during hydraulic fracture expansion.The stage spacing is positively correlated with the number of fractures and Young’s modulus of the cement and formation and is negatively correlated with the cluster spacing and horizontal principal stress difference.The sensitivity is the strongest when the Young’s modulus of the cement sheath is 10-20 GPa,and the sensitivity of the horizontal principal stress difference is the weakest.

关 键 词：Hydraulic fracturing Cementing interface Fracture propagation Fracturing stage spacing Wellbore integrity 

分 类 号：TE319[石油与天然气工程—油气田开发工程]