A new model for predicting hydraulic fracture penetration or termination at an orthogonal interface between dissimilar formations

作     者：Yu Zhao Yong-Fa Zhang Guo-Dong Tian Chao-Lin Wang Jing Bi Yu Zhao;Yong-Fa Zhang;Guo-Dong Tian;Chao-Lin Wang;Jing Bi

作者机构：College of Civil EngineeringGuizhou UniversityGuiyang550025GuizhouChina Guizhou Provincial Key Laboratory of Rock and Soil Mechanics and Engineering Safety(Guizhou University)Guiyang550025GuizhouChina School of Civil EngineeringChongqing UniversityChongqing400045China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2022年第19卷第6期

页      面：2810-2829页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082002[工学-油气田开发工程] 

基　　金：supported by the National Natural Science Foundation of China(No.52064006,52164001 and 52004072) the Guizhou Provincial Science and Technology Foundation(No.4Y044,No.292,No.GCC005 andN404) the China Scholarship Council program(202006050112) 

主　　题：Analytical model Hydraulic fracture Interface of dissimilar materials Vertical propagation behavior Parametric sensitivity analysis 

摘      要：Vertical height growth of hydraulic fractures(HFs)can unexpectedly penetrate a stratigraphic interface and propagate into neighboring layers,thereby resulting in low gas-production efficiency and high risk of groundwater contamination or fault reactivation.Understanding of hydraulic fracture behavior at the interface is of pivotal importance for the successful development of layered reservoirs.In this paper,a twodimensional analytical model was developed to examine HF penetration and termination behavior at an orthogonal interface between two dissimilar materials.This model involves changes in the stress singularity ahead of the HF tip,which may alter at the formation interface due to material heterogeneity.Three critical stress conditions were considered to assess possible fracture behavior(i.e.,crossing,slippage,and opening)at the interface.Then,this model was verified by comparing its theoretical predictions to numerical simulations and three independent experiments.Good agreement with the simulation results and experimental data was observed,which shows the validity and reliability of this model.Finally,a parametric study was conducted to investigate the effects of key formation parameters(elastic modulus,Poisson’s ratio,and fracture toughness)between adjacent layers.These results indicate that the variation in the introduced parameters can limit or promote vertical HF growth by redistributing the induced normal and shear stresses at the interface.Among the three studied parameters,Poisson’s ratio has the least influence on the formation interface.When the fracture toughness and elastic modulus of the bounding layer are larger than those of the pay zone layer,the influence of fracture toughness will dominate the HF behavior at the interface;otherwise,the HF behavior will more likely be influenced by elastic modulus.