硬岩水力定向压裂裂缝扩展对天然裂缝的响应行为  

Response Behavior of Artificial Fracture Propagation to Natural Fractures in Oriented Hydraulic Fracturing of Hard Rock Mass

作　　者：王伟澄 黄明清 黄敏 唐绍辉 WANG Weicheng;HUANG Minqing;HUANG Min;TANG Shaohui(Zijin School of Geology and Mining,Fuzhou University,Fuzhou 350108,China;Zijin Mining Group Co.,Ltd.,Shanghang 364200,China)

机构地区：[1]福州大学紫金地质与矿业学院,福建福州350108 [2]紫金矿业集团股份有限公司,福建上杭364200

出　　处：《金属矿山》2024年第4期53-61,共9页Metal Mine

基　　金：国家重点研发计划项目(编号:2022YFC2903904);国家自然科学基金项目(编号:51804079)。

摘　　要：水力压裂是硬岩金属矿山崩落法开采的关键预处理手段,但矿体中天然裂隙的存在限制了水力裂缝定向扩展与空间展布形态。为研究在含天然裂缝的铜矿体中天然裂缝的长度和水平距离对定向水力裂缝扩展路径的影响,利用ABAQUS建立了嵌入黏聚力单元的有限元模型,模拟不同天然裂缝长度和水平距离条件下的水力压裂行为。结果表明,天然裂缝的长度和水平距离对裂缝的扩展具有积极影响。天然裂缝长度与水力裂缝扩展半径呈指数关系,天然裂缝水平距离与水力裂缝扩展半径呈线性关系。在0~1.5 MPa低地应力差条件下,随着天然裂缝水平距离的减少或天然裂缝长度的增加,水力裂缝的扩展半径越大。研究结果对硬岩天然裂缝条件下的水力压裂裂缝定向扩展与调控有积极的指导意义。Hydraulic fracturing is a key preconditioning approach in block caving mining of hard-rock metal mines,however,natural fractures within the orebody tend to limit the oriented fracture propagation and spatial morphology of artificial fractures.To understand the influence of the natural fracture′s length and horizontal distance on the propagation path of oriented fracture within copper orebodies with natural fractures,a finite element numerical model embedded with pore pressure cohesive elements was established using ABAQUS,and hydraulic fracturing behaviors was simulated under variable natural fracture lengths and horizontal distance conditions.Results show that the length and horizontal distance of natural fractures lead to a positive effect on the propagation morphology and propagation law of fractures.The natural fracture length has an exponent relation to the propagation radius of artificial fractures,while the horizontal distance of natural fractures shows a linear relation with the propagation radius of hydraulic fractures.Regarding 0~1.5 MPa low in-situ stress difference,with the decrease of natural fracture horizontal distance,or with the increase of natural fracture length,the propagation radius of hydraulic fracture is larger,and other response laws of hydraulic to natural fracture.The study results have a possitive guilding significance for the directional propagation and control of hydraulic fractures under the condition of hard rock natural fractures.

关 键 词：黏聚力单元 裂缝扩展 天然裂缝 水力裂缝 孔隙发育 

分 类 号：TD315[矿业工程—矿井建设]