广东下庄矿田钻孔岩芯重定向方法

On drilling core reorientation in Xiazhuang ore field,Guangdong Province

古地磁法岩芯重定向具有经济、精度较高等优点。在进行前期岩芯取样时,传统的岩芯坐标系、样品坐标系以及垂直裂缝取样方法存在取样数量少或样品钻取时受到破坏等问题,因此提出一种在岩芯侧面任意位置垂直钻取样品的新方法,可灵活取样,极大地提高了岩芯样品的利用率和岩芯取样效率。为了深入理解新取样方法的岩芯定向过程,首先通过模仿野外古地磁岩芯定向过程获得岩芯样品相对于主参照线的原始方位;然后推导出岩芯样品坐标系—主参照线坐标系—地理坐标系之间的坐标转换公式,获得岩芯样品在地理坐标系下的磁偏角和磁倾角;最后结合广东下庄钻孔岩芯资料,实现了钻孔岩芯方位的初步恢复。

The paleomagnetic core reorientation is cost-effective and highly precise.Its preliminary work is sampling,but the traditional core sampling methods such as core coordinate system sampling,sample coordinate system sampling and vertical crack sampling,have the disadvantages of fewer samples or easily broken samples.Therefore,this paper proposes a new method for drilling samples vertically on the side of the core,which greatly improves the effectiveness of the core samples and core sampling efficiency.Meanwhile,in order to deeply understand the core orientation process of the new sampling method,first of all,the paper obtained the original orientation of the core sample relative to the main reference line by imitating the process of the field geomagnetic core orientation.Then,it drew out the formula between the sample coordinate system,the main reference line coordinate system and the geographic coordinate system,before obtaining the magnetic declination and magnetic inclination of the core samples in the geographic coordinate system.Finally,combing with the drilling core data of the Xiazhuang,Guangdong,it succeeded in initially recovering the borehole core orientation.