Crushing and embedment of proppant packs under cyclic loading: An insight to enhanced unconventional oil/gas recovery

作     者：K.M.A.S.Bandara P.G.Ranjith T.D.Rathnaweera W.A.M.Wanniarachchi S.Q.Yang K.M.A.S.Bandara;P.G.Ranjith;T.D.Rathnaweera;W.A.M.Wanniarachchi;S.Q.Yang

作者机构：Department of Civil EngineeringMonash UniversityBuilding 60MelbourneVictoria3800Australia State Key Laboratory for Geomechanics and Deep Underground EngineeringSchool of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou 221116China 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2021年第12卷第6期

页      面：376-393页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 0708[理学-地球物理学] 0704[理学-天文学] 082002[工学-油气田开发工程] 

基　　金：Civil Engineering Department at Monash University Deep Earth Energy Research Laboratory 

主　　题：Proppant Micro-CT analysis Proppant crushing Proppant embedment Secondary induced fractures Cyclic loading 

摘      要：Crushing and embedment are two critical downhole proppant degradation mechanisms that lead to a significant drop in production outputs in unconventional oil/gas stimulation projects. These persistent production drops due to the non-linear responses of proppants under reservoir conditions put the future utilization of such advanced stimulation techniques in unconventional energy extraction in doubt. The aim of this study is to address these issues by conducting a comprehensive experimental approach. According to the results, whatever the type of proppant, all proppant packs tend to undergo significant plastic deformation under the first loading ***, the utilization of ceramic proppants(which retain proppant pack porosity up to 75%), larger proppant sizes(which retain proppant pack porosity up to 15.2%) and higher proppant concentrations(which retain proppant pack porosity up to 29.5%) in the fracturing stimulations with higher in-situ stresses are recommended to de-escalate the critical consequences of crushing associated issues. Similarly, the selection of resin-coated proppants over ceramic and sand proppants may benefit in terms of obtaining reduced proppant *** addition, selection of smaller proppant sizes and higher proppant concentrations are suggested for stimulation projects at depth with sedimentary formations and lower in-situ stresses where proppant embedment predominates. Furthermore, correlation between proppant embedment with repetitive loading cycles was ***, microstructural analysis of the proppant-embedded siltstone rock samples revealed that the initiation of secondary induced fractures. Finally, the findings of this study can greatly contribute to accurately select optimum proppant properties(proppant type, size and concentration) depending on the oil/gas reservoir characteristics to minimize proppant crushing and embedment effects.