基于连续划痕实验确定复杂地层岩石强度参数的方法研究  

Determination of rock strength parameters during drilling based on continuous scratch tests

作　　者：刘洪涛 薄克浩[1,3] 金衍 卢运虎[1,3] 朱金智[2] 张震[2] 张峰[2] LIU Hongtao;BO Kehao;JIN Yan;LU Yunhu;ZHU Jinzhi;ZHANG Zhen;ZHANG Feng(College of Petroleum Engineering,China University of Petroleum-Beijing,Beijing 102249,China;PetroChina Tarim Oilfield Company,Kuerle 841000,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum-Beijing,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]中国石油塔里木油田公司,库尔勒841000 [3]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249

出　　处：《石油科学通报》2022年第4期532-542,共11页Petroleum Science Bulletin

基　　金：国家自然科学基金面上项目(52074314);国家自然科学基金企业联合基金集成项目(U19B6003-05-03)联合资助;国家自然科学石油化工联合基金重点支持项目(U1762215)。

摘　　要：岩石黏聚力和内摩擦角是进行井壁稳定和水力压裂研究的关键参数,目前常通过多组标准岩样的压缩剪切破坏实验进行评价(常规压缩实验,国际岩石力学学会标准)。但由于其制样要求复杂,对于取样困难的复杂岩体强度参数评价并不适用。基于塑性破坏模式下尖、钝刀头破岩力学模型,结合摩尔库伦破坏准则,建立了基于刀头破岩载荷确定岩石粘聚力和内摩擦角的力学模型;利用连续划痕实验设备,通过对划痕顺序间干扰性、划痕位置间替代性及不同刮深划痕破岩模式进行研究,形成了准确获得刀头破岩载荷曲线的划痕参数设置方法和划痕实验流程。分别利用新方法与常规三轴压缩法,对中国西部某油田吉迪克组泥岩进行了强度参数评价,对比发现两者测试结果基本保持一致,证实了新方法是可靠的。新方法制样简单,能够进行复杂岩性和结构的岩石强度参数测试;同时,实验过程中不破坏试件整体结构,结果重复性强,为研究水岩作用前后试样强度参数的测试提供了新手段。Rock cohesion strength and internal friction angle are the fundamental and important parameters of borehole stability and hydraulic fracturing research. The conventional method for obtaining the above rock strength properties is triaxial compression test standardized by the International Society of Rock Mechanics(ISRM). The rock mechanics parameters including compressive strength and elastic modulus can be obtained by applying a certain confining pressure to the specimen, and then gradually increasing the axial pressure until shear failure occurs in the rock sample. And because of the advantages of strong adaptability and accurate measurement, triaxial compression experiment method has been widely used. However, this method has high requirements for sample making and which will lead to rock sample breakage, so the sample can’t be reused again. Because it is difficult to make standard samples of complex rock mass, this method is not suitable in complex study. In this paper, based on the mechanical model of rock scratching with sharp and blunt cutters in plastic failure mode, and combined with Mol-coulomb criterion, the mechanical model of rock cohesion strength and internal friction angle were established by using the force of rock breaking with cutters. Then, with the continuous scratch test device, the influence of the order, location and depth of the sharp and blunt cutters on the rock breaking mechanical behavior of the cutters were evaluated, and the scratch parameter setting methods and scratch tests process for accurately obtaining the rock breaking stress curve of the cutters were proposed. The normal stress and shear stress were obtained by cutting the rock sample with sharp and blunt cutters, and then the rock mechanics parameters including cohesion strength and internal friction angle can be obtained by substituting them into the calculation model. Compared with the traditional triaxial compression test, the values of rock mechanical parameters measured by using the continuous scratch methods were con

关 键 词：强度参数 连续划痕 实验方法 复杂岩体 

分 类 号：TE311[石油与天然气工程—油气田开发工程]