基于地球椭球的真三维井眼定位方法

发布时间：2019-04-22 09:44

【摘要】：针对现行井眼定位方法存在的问题,提出真三维井眼定位方法,并进行算例分析。现行定位方法以网格北作为指北基准,基于地图投影坐标进行水平面定位,基于高程坐标进行垂向定位,且二者相互独立,只使用一点处的子午线收敛角和磁偏角来归算全井的井眼轨迹,存在固有缺陷和误差。基于地球椭球及其解算原理,揭示了井口坐标系与大地坐标系及高程坐标系之间的转换关系,提出了采用真北作为指北基准的真三维井眼定位方法。算例分析结果表明,现行定位方法算得的靶点垂深偏小、水平位移偏大,与真三维定位方法相比存在较大误差。真三维井眼定位方法从根本上解决了现行定位方法存在的问题,能精准定位靶点与井口间的相对位置,可显著提高井眼轨迹设计的精确性和可靠性。
[Abstract]:In view of the problems existing in the current borehole location method, the true three-dimensional borehole location method is proposed, and an example is given to analyze the real three-dimensional borehole location method. The current positioning methods take the north of the grid as the reference point, locate the horizontal plane based on the map projection coordinates, and locate the vertical direction based on the elevation coordinates, and the two are independent of each other. Only the meridian convergence angle and magnetic deviation angle at one point are used to reduce the hole trajectory of the whole well, and there are inherent defects and errors. Based on the earth ellipsoid and its solving principle, the transformation relationship between wellhead coordinate system, geodetic coordinate system and elevation coordinate system is revealed, and the true three-dimensional borehole location method using true north as the reference point of the north is put forward. The results of an example show that the vertical depth and horizontal displacement of the target calculated by the current localization method are smaller and the horizontal displacement is larger than that of the true three-dimensional localization method, and there is a large error compared with the true 3D positioning method. The true three-dimensional borehole location method fundamentally solves the problems existing in the current location method, which can accurately locate the relative position between the target and the wellhead, and can significantly improve the accuracy and reliability of wellbore trajectory design.
【作者单位】：中国石化石油工程技术研究院;
【基金】：国家科技重大专项“海相碳酸盐岩油气井井筒关键技术”(2011ZX05005-006)
【分类号】：TE24

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