考虑磁偏角时空变化的实钻轨迹精准定位

发布时间：2018-11-17 12:48

【摘要】：现行的井眼轨迹监测方法以网格北为指北基准,没有考虑子午线收敛角和磁偏角沿井眼轨迹和随时间的变化,致使北坐标、东坐标等参数明显存在误差。建立了以真北方向为指北基准的井口坐标系,通过揭示井口坐标系与大地坐标系之间的转换关系,提出了高精度井眼轨迹监测方法。这种高精度监测方法考虑了磁偏角的时空变化,利用国际地磁参考场随时随地求取磁偏角,并且不涉及子午线收敛角问题。结果表明:高精度监测方法与现行监测方法算得的垂深和水平长度相同,但北坐标、东坐标、水平位移和平移方位等参数不同。在地图投影变形大、地磁场变化大的地区钻井,尤其是钻大位移井,现行监测方法的计算误差可达数米,因此应使用高精度监测方法。
[Abstract]:The current well trajectory monitoring method takes the north grid as the reference point and does not take into account the variation of meridian convergence angle and magnetic deviation angle along the borehole trajectory and with time, resulting in obvious errors in parameters such as the north coordinates and the east coordinates. The wellhead coordinate system with the true north direction as the reference point is established. By revealing the conversion relationship between the wellhead coordinate system and the geodetic coordinate system, a high-precision wellbore trajectory monitoring method is proposed. This high precision monitoring method takes into account the temporal and spatial variation of the magnetic deviation angle and uses the international geomagnetic reference field to obtain the magnetic deflection angle at any time and anywhere and does not involve the meridian convergence angle problem. The results show that the vertical depth and horizontal length calculated by the high precision monitoring method are the same as those obtained by the current monitoring method, but the parameters of the north coordinate, the east coordinate, the horizontal displacement and the translation orientation are different. In the areas where the map projection deformation is large and the geomagnetic field changes greatly, especially in the large displacement wells, the calculation error of the current monitoring methods can reach several meters, so the high precision monitoring method should be used.
【作者单位】：中国石油化工股份有限公司石油工程技术研究院;
【基金】：国家重大科技专项(2011ZX05005-006)资助
【分类号】：TE24

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