考虑地下磁矿脉影响的井眼方位角校正方法  

Borehole Azimuth Correction Method Considering the Effect of Underground Magnetic Veins

作　　者：胡贵[1] 刘喆 刁斌斌[2] 于瑞丰 吴华鹏 张富磊 HU Gui;LIU Zhe;DIAO Binbin;YU Ruifeng;WU Huapeng;ZHANG Fulei(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100082,China;MOE Key Laboratory of Petroleum Engineering,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油勘探开发研究院,北京100082 [2]中国石油大学石油工程教育部重点实验室,北京102249

出　　处：《石油化工高等学校学报》2025年第2期54-61,共8页Journal of Petrochemical Universities

基　　金：国家自然科学基金项目(52234002,52474014)。

摘　　要：为了提高磁方位角的测量精度,获得精确的磁偏角信息,通常需要构建更高精度的当地地磁模型。相较于全球地磁模型,当地地磁模型包含地下磁矿脉在地表引发的磁异常信息。由于地下磁矿脉的埋藏深度和规模不同,其对不同井深处磁偏角的影响也各不相同。因此,在中深井(Z井)方位角校正时,有必要考虑地下磁矿脉的影响。利用ANSYS Maxwell数值模拟软件,建立了考虑埋藏深度、规模磁矿脉影响的地磁场模型;通过数值模拟,并结合中深井的实际钻井眼轨迹,提出了一种方位角校正方法,并量化评估了地下磁矿脉对方位角和井眼轨迹的影响。结果表明,在磁矿脉埋深达到2100 m时,地下磁矿脉对2000 m地层厚度内钻井方位角影响的偏移量约为0.6°;若考虑地下磁矿脉的影响,井眼轨迹难免会发生偏移,且偏移量随着井深的增加而增大,这可能会导致中深井脱靶等事故。因此,进行地下磁矿脉影响下的方位角校正对提高方位角测量精度、实现精准导向具有重要意义。In order to improve the accuracy of magnetic azimuth measurement,it is often necessary to establish a more accurate local geomagnetic model to obtain precise magnetic declination information.Compared with global geomagnetic model,local geomagnetic model contains magnetic anomaly information caused by underground magnetic ore veins at the surface.Considering the different burial depths and sizes of underground magnetic veins,their effects on magnetic declination at different borehole depths differ significantly.Therefore,it is necessary to consider the correction of the azimuth angle of medium and deep wells under the influence of underground magnetic veins.Based on ANSYS Maxwell numerical simulation software,the geomagnetic field model under the influence of magnetic veins of different burial depths and sizes was established.Through numerical simulation method and actual drilled borehole trajectory of a medium-deep well(Z well),a method of azimuth correction was given to quantitatively analyse the influence of underground magnetic veins on the azimuth and borehole trajectory.The results of the study show that the effect of underground magnetic veins on the azimuth of drilling within the 2000 m thickness stratum is about 0.6°under the condition that the magnetic veins are buried at a depth of 2100 m.After considering the influence of underground magnetic veins,the borehole trajectory is inevitably offset,and the offset increases with the depth of the well,which may cause offtargeting and other accidents for medium and deep wells.Therefore,it is of great significance to consider that the azimuth correction under the influence of geomagnetic veins can strongly improve the azimuth measurement accuracy and realise accurate guidance.

关 键 词：随钻测量 磁矿脉 方位角 中深井 数值模拟 

分 类 号：TE22[石油与天然气工程—油气井工程]