水力压裂裂缝扩展声发射破裂机制判定方法研究  

On the determination method of rupture mechanism in acoustic emission used in hydraulic fracturing fracture propagation

作　　者：梁天成[1,2] 付海峰[1,2] 刘云志[1,2] 修乃岭[1,2] 严玉忠[1,2] LIANG Tian-cheng;FU Hai-feng;LIU Yun-zhi;XIU Nai-ling;YAN Yu-zhong(Research Institute of Petroleum Exploration and Development, Langfang 065007, Hebei, China;Key Laboratory of Reservoir Stimulation, CNPC, Langfang 065007, Hebei, China)

机构地区：[1]中国石油勘探开发研究院,河北廊坊065007 [2]中国石油天然气集团公司油气藏改造重点实验室,河北廊坊065007

出　　处：《实验力学》2019年第2期358-364,共7页Journal of Experimental Mechanics

基　　金：国家重大专项<储层改造关键技术及装备>(2016zx005023)资助

摘　　要：水力压裂室内模拟实验系统可以模拟各种地层条件下的压裂实验,实验中利用声发射设备对裂缝的起裂和延伸的过程进行实时动态监测,实验后对形成裂缝的形态进行直接观察,从而为压裂理论的研究和论证提供一种重要的手段。本文利用声发射技术对砂岩、煤岩、页岩三类岩石水力压裂模拟实验进行了监测,对声发射数据进行了分析,并把日本混凝土材料协会(JCMS-III B5706 2003)定义的两个参数(频度和RA值)成功地应用于水力压裂模拟实验。研究表明:用声发射信号的频度和RA值两个参数联合评价压裂模拟实验的破裂机制是可行的,可以区分张性破裂和剪切破裂;致密砂岩主要形成张性裂缝。煤岩和页岩既有张性裂缝,又有剪切裂缝,这与煤岩和页岩存在天然裂缝,压裂时水力裂缝与天然裂缝相互干扰作用有关。上述结果可用于指导水力压裂现场微地震监测。Hydraulic fracturing laboratory simulation experiment can simulate fracturing experiment under various stratigraphic formation conditions. In experiment, real-time dynamic monitoring of crack initiation and extension process was carried out by acoustic emission equipment. After experiment, the morphology of cracks may be observed directly.Thus, it provides an important means for study and demonstration of fracturing theory. In this paper, acoustic emission technique is used to monitor hydraulic fracturing simulation experiment of three lithologic rocks including sandstone, coal and shale rock, and acoustic emission data are analyzed. Two parameters defined by Japanese concrete material association (JCMS-III B5706 2003) are successfully applied to the hydraulic fracturing simulation experiment. Study results show that it is feasible to evaluate the fracture mechanism in fracturing simulation experiment by combining two parameters of acoustic emission: frequency of acoustic emission signals and RA value, which can distinguish tensile rupture from shear rupture. Tight sandstone produces tensile rupture. For coal and shale rocks with relatively more developed natural fractures, there are not only tensile rupture, but also a certain number of shear rupture. Shear rupture is easy to occur due to the existence of natural cracks, or due to the interference of hydraulic fractures and natural fractures. Above results may be used to guide microseismic monitoring in hydraulic fracturing site.

关 键 词：水力压裂 岩石力学 声发射 破裂机制 剪切破裂 张性破裂 

分 类 号：TD313[矿业工程—矿井建设]