套管周围磁场分布规律研究

发布时间：2018-08-13 11:40

【摘要】：目前,很多陆地油田进入开发后期,为了达到增产增效的目的,所钻加密井、调整井越来越多;为了合理利用空间以及降低成本,海洋丛式井井口间距比较小,使得上部直井段井间距也较小。因此,如何避免井眼碰撞已经成为很重要的问题。常规的井眼防碰分析方法很大程度上依赖于测斜仪数据的精确性,而测斜仪的测量精度很容易受到外加磁场源—尤其是邻井套管的影响。基于套管周围磁场分布规律可以判断正钻井相对于邻井套管的空间位置,开展油气井套管周围磁场分布规律研究,可以增强对邻井套管磁干扰的认识,有助于建立磁场敏感性因素与磁场范围的表征关系,也有助于建立适应范围广、成本低的防碰方法。本文对套管周围磁场影响因素进行了分析,指出套管感应磁场、剩磁及套管接箍是影响套管周围磁场的主要因素,从理论和实验两方面探讨了套管周围的磁场分布规律。主要研究内容及成果包括:建立了无限长直套管周围磁场模型,采用分离变量法求解,并采用向量投影方式得到了任意姿态套管周围磁场模型;采用三维积分方程法建立了有限长直套管周围磁场模型;采用全尺寸套管进行套管周围磁场测试分析,分别对不同方位和距离的场点总磁场、水平磁场、竖直磁场以及磁倾角的异常值与变化率进行分析,得到了不同磁场参数沿套管径向和切向的变化规律,为今后反演邻井套管的空间位置奠定了基础;采用小尺寸钢管柱进行了空间磁场测试,分别探讨了铁磁性管柱在有剩磁和无剩磁、有接箍和无接箍时空间磁场变化规律;将理论模型与实验结果进行了对比验证,最终得到了修正的感应磁场理论模型。
[Abstract]:At present, many terrestrial oil fields are entering the late stage of development, in order to achieve the purpose of increasing production and increasing efficiency, more and more infill wells and adjustment wells have been drilled. In order to make rational use of space and reduce costs, the spacing between the wellheads of ocean cluster wells is relatively small. The interval between the upper section of the vertical well is also smaller. Therefore, how to avoid borehole collision has become a very important issue. The conventional borehole anti-collision analysis method depends largely on the accuracy of the data of the inclinometer, and the accuracy of the inclinometer is easily affected by the external magnetic field source, especially the casing in the adjacent well. Based on the distribution law of magnetic field around casing, the spatial position of positive drilling relative to adjacent casing can be judged, and the study of magnetic field distribution around casing in oil and gas wells can enhance the understanding of magnetic interference of casing in adjacent wells. It is helpful to establish the relationship between magnetic field sensitivity factors and magnetic field range, and also to establish a wide range and low cost anti-collision method. This paper analyzes the influence factors of the magnetic field around the casing, and points out that the inductive magnetic field, the remanent magnetic field and the casing coupling are the main factors affecting the magnetic field around the casing. The distribution law of the magnetic field around the casing is discussed theoretically and experimentally. The main research contents and results are as follows: the magnetic field model around the infinite straight casing is established and solved by the separation variable method, and the magnetic field model around the casing with arbitrary attitude is obtained by vector projection. The magnetic field model around a finite length straight casing is established by using the three-dimensional integral equation method, and the magnetic field around the casing is measured and analyzed by using the full-size casing. The total magnetic field and the horizontal magnetic field of the field point with different azimuth and distance are measured and analyzed respectively. The abnormal values and variation rate of vertical magnetic field and magnetic dip angle are analyzed, and the variation law of different magnetic field parameters along the casing radial and tangential direction is obtained, which lays a foundation for retrieving the space position of casing in adjacent wells in the future. The spatial magnetic field changes of ferromagnetic pipe column with and without remanence, coupling and without hoop are discussed, and the theoretical model and experimental results are compared and verified. Finally, the modified theoretical model of induction magnetic field is obtained.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE931.2

【参考文献】