考虑裂缝表面细观力学的闭合规律研究

发布时间：2018-04-16 03:06

  本文选题：裂缝表面形态 + 闭合量　； 参考：《成都理工大学》2015年硕士论文

【摘要】：压裂或酸压工艺已经成为碳酸盐岩油气藏开采、建产、稳产和增产的关键技术之一。压裂或酸压后形成一定长度的人工裂缝为油气提供通道或是沟通天然裂缝时,其导流能力则就成为评价施工效果的重要参数之一。而人工裂缝的导流能力与裂缝表面的细观形态密切相关,不同岩性、不同地质条件下岩石的裂缝表面各异,因此定量化研究裂缝表面的形态特征和闭合规律显得尤为重要。目前对裂缝表面形态的定量化研究较少,特别是裂缝两面在应力作用下的状态缺乏研究,前人在对裂缝闭合规律研究时多基于岩石力学参数建立模型,并未考虑微凸体的不同变形阶段。而前人在对粗糙面接触研究中,虽然完善了变形阶段,但建立的模型存在不连续性和不光滑性,目前对裂缝表面微凸体接触的理论研究相对比较薄弱。论文在大量文献调研基础之上,对碳酸盐岩裂缝的特征进行了概述,总结裂缝表面形态定量化研究的难点及发展趋势;总结出一套测试不同闭合压力下裂缝面法向闭合量的实验方法及流程,精确测量不同闭合应力下裂缝面的法向闭合量;采用新型三维数字化方法对裂缝表面形态进行数字化成图,经过与导师共同设计研发的三维数据处理软件,对裂缝面数据进行深入分析处理,从而获得裂缝面的特征参数,并通过这些特征参数对裂缝面进行定量化表述;分析研究了裂缝特征参数与闭合应力的关系;结合实验验证了弹塑性混合变形区间的存在;通过对经典接触模型的讨论,基于一定的假设,建立了微凸体和粗糙面的接触理论模型,获得了模型的解析解。论文取得的主要研究认识与成果有:(1)总结出一套测试不同闭合压力下裂缝面法向闭合量的实验方法及流程,准确的评价法向闭合量随闭合应力的变化关系;在法向闭合量随闭合应力的变化关系曲线上,变形初期随着闭合应力增加,法向闭合量迅速增加;在变形后期则是呈现相反的变化趋势。(2)基于新型三维形貌扫描仪对裂缝面进行三维扫描,获得裂缝面真实的三维图像。根据“三维扫描解释软件”对扫描数据进行处理分析,获得裂缝面在组合形态下的特征参数(吻合度和裂缝间距),通过吻合度和裂缝间距对裂缝面组合形态进行定量化表征。(3)根据法向闭合量与闭合应力关系曲线,在10MPa时闭合量曲线出现拐点。在小于10MPa的压力时,闭合应力与法向闭合量满足二次多项式关系。说明在低闭合应力下,裂缝面的法向闭合主要跟微凸体的弹塑性变形有关;而高闭合应力下,则可能是由于微凸体破碎等因素所导致。闭合应力在大于10MPa时,法向闭合量增幅不明显,这是由于大量微凸体塑性变形所导致。(4)根据吻合度的定义,结合法向闭合量与闭合应力关系,求出了吻合度与闭合应力的关系,可以通过此关系预测不同闭合应力下裂缝面的吻合度,从而获得其实际接触面积,预测实际接触面积变化趋势。(5)通过实验测得不同闭合应力加载并卸载后的裂缝面吻合度,结合吻合度与闭合应力的关系曲线,获得了计算吻合度与实测吻合度的对比关系,从而验证了裂缝面接触时既有弹性变形也有塑性变形。(6)根据经典接触理论模型,建立了论文的微凸体接触理论模型,并通过数学方法求解出了完全弹性-弹塑性混合变形-完全塑性变形三个阶段的接触变量与法向闭合量的关系,并建立了粗糙面接触模型。通过对比经典的接触模型,验证了论文模型的适用性。论文旨在通过分析裂缝表面的形态,建立基于细观力学的裂缝接触模型,引入插值法对复杂接触问题进行求解,获得较为简单的解析解,为裂缝的精细研究提供支持。
[Abstract]:Fracturing and acid fracturing technology has become the carbonate oil and gas reservoir exploitation, construction of production, one of the key technologies of stable and high yield. The artificial fracturing or acid fracturing after a certain length of the channel is provided for the oil and gas or communication of natural fracture, the diversion ability becomes one of the important parameters to evaluate the construction effect. The conductivity and fracture surface of fracture micro morphology is closely related to lithology, fracture surface of different rocks under different geological conditions, so the fixed shape and surface crack closure rules of quantitative research is particularly important. The fracture surface morphology and quantitative research, especially the crack faces under stress the lack of research, the previous research on crack closure rules when the rock mechanics parameters based on the model, did not consider the asperity of different deformation stages. And the previous on rough surface Contact study, while improve the deformation stage, but the model is not continuous and smooth, the current theoretical research on the crack surface asperity contact is relatively weak. In the above literature research foundation, characteristics of carbonate fracture were summarized, the difficulties and the development trend summary quantitative research the fracture surface morphology; summed up a set of experimental methods to test different closure pressure closed the crack surface method and process, accurate measurement of different closure stress crack closure method to hypospadias; using the new 3D digital method for digital mapping of fracture surface morphology, through data processing and 3D software co design tutorial the research on the crack surface, in-depth data analysis and processing, so as to obtain the characteristic parameters of cracks, and cracks on the surface were quantitatively expressed by these parameters points; Study on the relationship between parameters and characteristics of closed fracture stress; combined with the experimental verification of the elastic-plastic deformation of mixed interval existence; through the discussion of classical contact model, based on certain assumptions, a micro convex body and rough surface contact model, the analytical solution of the model. The main research understanding and results are as follows: (1) summarize a set of experimental methods to test different closure pressure closed the crack surface method and process, accurate evaluation method to the closure changes with closure stress; curves to closed in with the closure stress on early deformation with closure the normal force increases, the rapid increase of closed; in the later period of deformation is the opposite trend. (2) a new 3D scanner to scan the crack surface based on 3D images of fracture surface. According to the real 3D scan Description interpretation processing software analysis of the scanning data, get characteristic parameters of crack in the face of the form (degree of agreement and crack spacing), through anastomosis of crack spacing and quantitative characterization of fracture surface combination form. (3) according to the law to the closure and closure stress curve, closed at 10MPa the amount of curve inflection point. In less than 10MPa pressure, closure stress and normal closed rate to meet the two polynomial relationship. In the low closure stress, crack the normal closure with asperity elastic-plastic deformation; and high closure stress, it may be due to micro convex the broken body caused closure stress. In more than 10MPa, to increase the volume of closure is not obvious, this is due to the large number of asperities caused by plastic deformation. (4) according to the degree of agreement to the definition of closed and closed stress method, calculated the degree of agreement With closure stress, through this prediction of different crack closure stress hypospadias fit, so as to obtain the actual contact area, predict the actual contact area change trend. (5) measured with different loading and unloading should be closed fracture surface after the kiss degree of curve fit and close combination stress, obtained the calculation coincides with the measured results of the correlation degree, which verified the crack surface contact when it has elastic deformation is plastic deformation. (6) according to the classical contact theory model, established the asperity contact model, and the relationship between the contact variables and completely elastic elastic plastic deformation and plastic deformation is completely mixed in three stages to the closure by mathematical method, and establishes the contact model of rough surface contact model. By comparing with classical, proves the applicability of the model. Aiming at establishing the contact model based on meso mechanics, the interpolation method is applied to solve the complex contact problem, and a simpler analytical solution is obtained, which provides support for the detailed research of cracks.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.2

【参考文献】

中国期刊全文数据库 前5条

1 龚云蕾;刘平礼;罗志峰;陈霄;;酸压裂缝导流能力计算模型的研究现状[J];长江大学学报(自科版);2013年20期

2 刘慕溪;;数值分析中常见插值法的浅析[J];科技致富向导;2011年24期

3 姜琴;周天宏;;常见的插值法及其应用[J];郧阳师范高等专科学校学报;2006年03期

4 易成;王长军;张亮;陈忠辉;谢和平;;基于两体相互作用问题的粗糙表面形貌描述指标系统的研究[J];岩石力学与工程学报;2006年12期

5 唐志成;夏才初;宋英龙;付朋方;;考虑基体变形的节理闭合变形理论模型[J];岩石力学与工程学报;2012年S1期

中国博士学位论文全文数据库 前1条

1 伊向艺;碳酸盐岩储层交联酸酸压技术研究与应用[D];成都理工大学;2006年

中国硕士学位论文全文数据库 前1条

1 贾洪强;岩石节理面表面形态与剪切破坏特性的实验研究[D];中南大学;2011年

，

本文编号：1757009