【作者】 张敏；

【导师】 杨秀娟；

【作者基本信息】 中国石油大学 ， 工程力学， 2008， 硕士

【摘要】 油藏地应力对油气资源的形成、运移及储集等有直接控制作用,裂缝是油气的主要或重要渗流通道。因此,研究储层的地应力特征及分析裂缝发育情况对油田开发有重要的工程指导作用。本文基于声波测井资料研究油田储层的地应力及裂缝发育特征,主要研究成果如下:(1)分析了储层地应力特征的计算方法,确定了以声波测井法、水力压裂法和有限元数值模拟方法作为本文地应力分析的理论依据。(2)针对某一研究区块分别应用声波测井法、水力压裂法计算研究区块典型井点的地应力值;并且以水力压裂法确定的典型井点的地应力大小和方向作为约束目标,对研究区块的地应力场进行有限元数值模拟,得到储层平面的地应力分布规律。并将不同方法得到的地应力结果进行对比分析。(3)在对研究区块应用有限元模拟计算储层地应力的基础上,根据破裂准则研究了该区块储层平面的裂缝发育特征,得出了储层裂缝发育方位、破裂率分布规律,绘出区块的裂缝发育方位图、破裂率等值线图等。(4)储层裂缝发育规律研究及地应力分布的计算都与地层力学参数有密切关系。根据声波测井信息提取地层的纵波、横波,结合密度资料及相关计算准则,采用VB语言编制了声波测井计算分析软件,从而计算岩石力学参数,分析区块中典型井点沿深度连续分布的地应力特征及裂缝发育规律。(5)分析了油田开发过程中水力压裂裂缝与地应力间的关系,得到了油层主应力的大小关系对压裂裂缝形态的影响规律;研究了合理注采井网及合理井网密度之间的关系,得到井网与地应力之间的优化匹配关系。根据得到的地应力特征与压裂缝长度、方位及注采井网井距之间的规律,确定了所研究区块人工压裂裂缝的方向及其井网井距部署。更多还原

【Abstract】 Reservoir stress suggests a direct control effect of oil and gas formation and movement, and the fracture is the major seepage channel of oil and gas. So,study on in-situ stress character and fracture development of reservoir has a very important guidance meaning to the engineering.The in-situ stress and crack development characteristics of oilfield reservoir based on acoustic logging data are studied in this paper, and the major contents are summarized as follows:Firstly, this paper analyses the calculation methods of in-situ stress distribution, and the main methods include acoustic logging, hydraulic fracturing and finite element simulation. The methods can be considered as theoretical basis for analysis of in-situ stress.Secondly, the methods of sonic logging and hydraulic fracturing are employed to calculate the principal stress in a certain studied block. Then, with the size and orientation of in-situ stress in typical well as constraint target, finite element numerical simulation was performed to research the distribution of in-situ stress in the block, and the law of in-situ stress distribution was found. The results of in-situ stress obtained from the three methods were also compared in this paper.Thirdly, based on the results of in-situ stress in the block, finite element method was applied to obtain the feature of fracture development on reservoir plane. According to the criteria of rock rupture, fracture development graph and contour map of breaking rate were drawn in the block.Fourthly, the formation mechanical properties have close relationship with development law of cracks in oilfield reservoir as well as the distribution of in-situ stress. The compressional and shear waves in a formation were extracted based on acoustic logging information, and application software of acoustic logging was compiled by combining with density data and related calculation criterion.Finally, the relationship between hydraulic fracturing crack and in-situ stress was analyzed, and the effect law of relative in-situ stress on fracture morphology was getted.The paper also studied the relationship between reasonable well network and well spacing density, then, the optimization matching relationship between well pattern and in-situ stress was obtained. Baesd on the law of above mentioned, the orientation of hydraulic fracturing and deployment of well pattern and spacing were determined.更多还原