Three-component magnetic logging in the Outokumpu deep drillhole

奥托昆普深钻孔三分量磁测井

• 批准号: 65348769
• 负责人: Professor Dr. Andreas Hördt
• 金额: --
• 依托单位: Institut für Geophysik und Extraterrestrische Physik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/65348769?language=en
• 关键词: Three; component; magnetic; logging; Outokumpu

One of the aims of the Outokumpu deep drilling project in Finland is to obtain an understanding of the deep structure of the Cu-Co-Zn ore deposits. The ore is hosted by the Outokumpu formation, consisting of black shales, serpentinite and skarn rocks, which was transsected by the drillhole between 1300 and 1500 m depth. We carried out threecomponent magnetic logging and we will derive the rock magnetisation from the measured magnetic field. The integrated interpretation of our results with data from laboratory investigations carried out in a parallel project, will enable us to test various hypotheses on the tectonic evolution of the Outokumpu assemblage. We aim at an estimation of the magnetisation vector, and in particular its declination, which is generally considered difficult. We use the Göttingen borehole magnetometer (GBM), which is equipped with fiber-optic gyros allowing an independent orientation of the tool. The favourable conditions at the Outokumpu hole, an open section between 40m and 2500m, continuous coring, cool temperatures and a highly magnetised section embedded between weakly magnetised layers, will allow an unprecedented accuracy. The detailed evaluation of the results based on data redundancy and laboratory measurements, and the identification of the most critical error sources will have important implications for the application of borehole magnetometers in general.

芬兰Outokumpu深钻项目的目的之一是了解铜钴锌矿床的深部结构。矿石位于Outokumpu地层，由黑色页岩、蛇纹岩和矽卡岩组成，钻孔在1300至1500米深之间横切。我们进行了三分量磁测井，我们将推导出岩石磁化强度从测量的磁场。综合解释我们的结果与数据进行了实验室调查的一个平行的项目，将使我们能够测试各种假设的构造演化的Outokumpu组合。我们的目标是估计的磁化矢量，特别是它的decompensation，这通常被认为是困难的。我们使用哥廷根钻孔磁力仪（GBM），它配备了光纤陀螺仪，允许工具的独立方向。Outokumpu孔的有利条件，40米至2500米之间的开放部分，连续取芯，凉爽的温度和嵌入弱磁化层之间的高磁化部分，将允许前所未有的准确性。基于数据冗余和实验室测量的结果的详细评估，以及最关键的误差源的识别将对钻孔磁力计的应用产生重要影响。