深部岩石力学强度准则与参数确定方法研究

发布时间：2018-05-27 17:25

本文选题：深部岩石 + 强度　；参考：《西南石油大学》2017年硕士论文

【摘要】：深部岩石力学研究是指导油气资源勘探与开发的基础理论之一。实践表明,全面掌握与认识某个区域构造的深部地层岩石力学性质需要一定的过程和周期,一般在完成数口井后,通过对钻井、地质录井资料进行综合分析,才能逐步认识,如何正确认识深部岩石力学性质和缩短认识的过程是石油工程岩石力学领域关注的主要问题之一。国内外学者从岩石强度准则、岩石力学试验等角度对岩石强度参数进行了研究,但这些研究主要针对浅层岩石,对于深部地层的研究较少。本文以砂岩,玄武岩以及花岗岩作为研究对象,从岩石力学试验数据以及相关资料分析了深部地层高压条件下各类岩石强度准则的适应性。分别从理论分析、试验评价展开研究,对少岩样获取岩石强度参数的试验方法进行了研究,形成了适用于深部岩石强度参数获取的试验方法,以及适用于深部岩石的强度准则。论文主要研究内容如下:(1)调研现有各类岩石强度准则以及已有相关试验数据,分析深部地层岩石不同于浅层岩石的地方,从理论上讨论了各类准则对于研究深部岩石的适应性。(2)基于需要岩石样品的数量,将岩石力学试验划分为常规岩石力学试验和少岩样获取岩石力学强度参数试验两类试验,针对这些试验得到的岩石抗压强度、应力应变曲线特征、加载曲线特征以及岩石破坏方式进行逐一分析。试验研究结果表明:多级加载试验中高围压下的应变硬化是造成岩石强度严重偏大的主要原因,其强度大小与增加围压时岩石的累积径向应变成正比。(3)选取露头砂岩,玄武岩,花岗岩等不同类型岩石模拟井下条件进行力学与物性参数实验。结果表明砂岩的应变硬化程度最大,建立强度参数修正模型,利用Matlab软件进行编程计算,并对比常规试验数据,修正模型能将砂岩这一类岩石的多级加载试验结果的相对误差控制在10%以内。最终对比各类强度准则,其中线性的Mohr-Coulomb准则对于砂岩常规三轴压缩试验,玄武岩多级加载试验和常规三轴试验都适用,而对于砂岩多级加载试验不适用;指数型的双参数Bieniawski准则对于砂岩不管是修正前的多级加载试验数据还是修正后的多级加载试验数据,都是比较适应的,但是对于玄武岩这类较硬岩石的多级加载试验,该准则不再适用。
[Abstract]:The study of deep rock mechanics is one of the basic theories guiding the exploration and development of oil and gas resources. The practice shows that it is necessary to master and understand the mechanical properties of deep formation rock in a certain area. Generally speaking, after several wells have been completed, the comprehensive analysis of drilling and geological logging data can gradually be realized. How to correctly understand the mechanical properties of deep rock and shorten the process of understanding is one of the main problems in petroleum engineering rock mechanics field. From the point of view of rock strength criterion and rock mechanics test, scholars at home and abroad have studied rock strength parameters, but these studies mainly focus on shallow rocks, but less on deep strata. In this paper, sandstone, basalt and granite are taken as research objects. The adaptability of various rock strength criteria under high pressure conditions in deep strata is analyzed from rock mechanics test data and related data. Based on the theoretical analysis and experimental evaluation, the test methods for obtaining rock strength parameters from less rock samples are studied, and the test methods suitable for the acquisition of deep rock strength parameters and the strength criteria suitable for deep rock are formed. The main contents of this paper are as follows: (1) to investigate the existing rock strength criteria and relevant experimental data, and to analyze where the deep strata rock is different from the shallow rock. Based on the quantity of rock samples, rock mechanics test is divided into two types: conventional rock mechanics test and rock mechanical strength parameter test with less rock samples, which are used to study the adaptability of various criteria to the study of deep rock. (2) based on the quantity of rock samples, the rock mechanics test is divided into two types: conventional rock mechanics test and rock mechanical strength parameter test. The characteristics of compressive strength, stress-strain curve, loading curve and failure mode of rock obtained from these tests are analyzed one by one. The experimental results show that the strain hardening under high confining pressure is the main cause of the serious overhang of rock strength in multistage loading test, and its strength is directly proportional to the cumulative radial strain of rock under increasing confining pressure.) outcrop sandstone and basalt are selected. Experiments on mechanical and physical parameters of different types of rock such as granite are carried out under simulated downhole conditions. The results show that the strain hardening degree of sandstone is the largest. The strength parameter correction model is established, and the program calculation is carried out by using Matlab software, and the conventional test data are compared. The modified model can control the relative error of the multistage loading test results of sandstone rock to less than 10%. The linear Mohr-Coulomb criterion is suitable for conventional triaxial compression test, basalt multistage loading test and conventional triaxial test, but not for sandstone multistage loading test. The exponential two-parameter Bieniawski criterion is suitable for sandstone multistage loading test data before modification and multistage loading test data after revision, but for hard rock such as basalt, multistage loading test, The guideline is no longer applicable.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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