基于有限元方法电法测井模型的数值仿真及应用

发布时间：2018-05-13 16:30

本文选题：有限元方法 + 区域分解　；参考：《电子科技大学》2015年硕士论文

【摘要】：随着地球物理探测以及测井技术的快速发展,人们对于测井仪器的探测能力有了更高的要求。目前测井仪器开发主要面临以下的困难:首先,仪器的结构更加复杂,探测器前端有更多精细结构的传感器;其次,随着定向井、倾斜井、水平井以及大位移井的出现,地层情况变得更加复杂;最后,随着二次开发以及油气资源的紧缺,对于仪器的探测精度以及探测能力有了更高的要求。面对这些新的工程挑战,本文采用有限元方法以及区域分解方法,对复杂的测井模型进行精密建模,对于多尺寸大物理模型进行区域分解建模并且求解。本文考察了一种基于柱体电容模型的传感器探头,该探头用于随钻测量油基泥浆的电参数。通过对该结构进行工作频率的考察以及结构的优化,使得其能覆盖电阻率??1000~1000000??m和介电常数1~80r??的测量范围。最后通过对实验样机进行加工和测量,得到了理想的测试结果。其次,针对目前随钻岩芯电参数测量遇到的难题,本文验证了一种可行的设计方案。通过在传统的极板周围增加屏蔽电极,从而聚焦电流流过岩石内部,突破井下复杂环境对测量造成的影响。随后还通过一系列的考察,分析并给出了该仪器模型的工作原理和工作模式,为该仪器的设计以及应用提供理论基础。介电测井技术是电磁波测井技术的重要补充,其主要用于探测电阻率测井无法分辨的地层。介电扫描(dielectric scanner)测井仪器的开发为介电测井提供了可靠的数据来源。本文结合介电扫描仪器的模型特点,采用区域分解方法对介电测井仪器进行详细的考察,给出了该仪器随地层电参数变化的响应特性曲线。本文还分析了该仪器的垂直分辨率以及探测深度等重要参数,对该仪器进行了全面的分析考察。
[Abstract]:With the rapid development of geophysical exploration and logging technology, people have higher requirements for logging tools. At present, the development of logging tools mainly faces the following difficulties: first, the structure of the tool is more complex, and the detector front end has more sensors with fine structure; secondly, with the appearance of directional wells, inclined wells, horizontal wells and extended reach wells, Finally, with the secondary development and the shortage of oil and gas resources, there is a higher requirement for the precision and capability of the instrument detection. In the face of these new engineering challenges, this paper uses the finite element method and the region decomposition method to model the complex logging model precisely, and to model and solve the multi-size large-scale physical model. In this paper, a sensor probe based on cylindrical capacitance model is investigated, which is used to measure electric parameters of oil based mud while drilling. Through the investigation of the working frequency and the optimization of the structure, the structure can be covered with the resistivity of 1000000 ~ 1000000m and the dielectric constant of 1 ~ 80rg? Range of measurements. Finally, the ideal test results are obtained by machining and measuring the experimental prototype. Secondly, this paper verifies a feasible design scheme in view of the difficulties encountered in the measurement of core electrical parameters while drilling. By adding shielding electrodes around the traditional plate, the focus current flows through the rock, and the influence of the complex underground environment on the measurement is broken. Then through a series of investigations, the working principle and working mode of the instrument model are analyzed and given, which provides a theoretical basis for the design and application of the instrument. Dielectric logging technology is an important supplement to electromagnetic wave logging technology, which is mainly used to detect strata which cannot be distinguished by resistivity logging. The development of dielectric scanning tool provides a reliable data source for dielectric logging. Combined with the model characteristics of dielectric scanning instrument, the dielectric logging tool is investigated in detail by using the method of domain decomposition, and the response characteristic curve of the change of electric parameters in the instrument is given. This paper also analyzes the vertical resolution and depth of the instrument, and makes a comprehensive analysis and investigation of the instrument.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.81

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