延长气田声发射实验地应力场研究及应用

发布时间：2018-02-28 20:07

本文关键词： 原地应力声发射实验井壁稳定性　出处：《西安石油大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着油气田开发难度的不断加大,地应力场的研究显得愈加重要,例如钻井过程中经常由于对地应力场的了解不够深入,而发生井壁坍塌事故,造成巨大的经济损失。本文在有限元差分理论的基础上,利用声发射实验获取延长气田X区块地应力值,借助Abaqus有限元分析软件,对该区块原始地应力场及开钻后井眼附近地应力场分布规律进行了模拟,通过模拟获取不同钻井液密度情况下井眼附近地应力场分布情况,根据MC剪切破坏准则及井眼周向应力分布情况判断井壁稳定性,从而得出合理的钻井液安全密度窗口。在研究过程中,通过将有限元模拟结果与室内实验结果进行对比发现,在只考虑重力作用情况下,垂直地应力值与实验值基本吻合而水平方向应力值与实验值差别比较大,分析原因为构造应力等其他影响因素而引起的异常,因此利用数值拟合方法将数据进行处理,再次进行地应力场平衡模拟,获取模拟结果与实验结果相匹配,误差范围可以控制到6%之内。
[Abstract]:With the increasing difficulty of oil and gas field development, the study of in-situ stress field becomes more and more important. For example, during drilling process, well wall collapse often occurs due to the lack of deep understanding of in-situ stress field. On the basis of finite element difference theory, acoustic emission experiments are used to obtain the in-situ stress values of the X block of the gas field, and the finite element analysis software Abaqus is used. The distribution law of the original stress field and the in-situ stress field near the borehole after drilling is simulated, and the distribution of the in-situ stress field near the borehole under different drilling fluid density is obtained by simulation. According to MC shear failure criterion and borehole circumferential stress distribution, the stability of borehole lining is judged, and a reasonable safe density window of drilling fluid is obtained. In the course of the study, the finite element simulation results are compared with the experimental results in laboratory. When gravity is considered only, the vertical stress value is basically consistent with the experimental value, but the horizontal stress value is quite different from the experimental value. The anomalies caused by other factors such as tectonic stress are analyzed. Therefore, the numerical fitting method is used to process the data and to simulate the geostress field again. The simulation results are matched with the experimental results, and the error range can be controlled to less than 6%.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE21

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