Downhole Measurements in the AND-1B Borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica
Downhole Measurements in the AND-1B Borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica
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南极洲 ANDRILL 麦克默多冰架项目 AND-1B 钻孔的井下测量
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Hansaraj
中科院分区：
文献类型：
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作者：
R. Morin;T. Williams;S. Henrys;T. Crosby;D. Hansaraj
作为为麦克默多冰架（MIS）项目定义的冰上科学计划的一部分，在AND-1B钻孔中收集了一套全面的井下测量数据。在两个作业阶段记录地球物理测井，包括井径、温度、流体电导率、感应电阻率、磁化率、自然伽马活动、声波电视、井斜和地层倾角。此外，还获得了两个标准垂直地震剖面（VSP）和一个步行VSP。由于井眼条件不稳定，没有进行放射性测井（孔隙度和密度）。虽然钻孔的总深度为海底以下1285米（mbsf），但现场测量的深度范围受到钢丝绳长度（1018 mbsf）的限制，并且由于钢套管的存在，一些地球物理测井曲线无效。一个深度校正是为了解释井下测量和岩心之间深度的系统差异，因此，测井响应可以直接与岩心性质进行比较。所得资料可用于研究旋回性与气候、热流与流场、构造与应力。当与岩心上测量的物理性质和裂缝相结合时，这些信息应该在解决本研究的许多科学目标方面发挥重要作用。
A comprehensive set of downhole measurements was collected in the AND-1B drillhole as part of the on-ice scientifi c programme defi ned for the McMurdo Ice Shelf (MIS) Project. Geophysical logs were recorded over two operation phases and consisted of calliper, temperature, fl uid conductivity, induction resistivity, magnetic susceptibility, natural gamma activity, acoustic televiewer, borehole deviation, and dipmeter. In addition, two standard vertical seismic profi les (VSP) and one walk-away VSP were obtained. Radioactive logs (porosity and density) were not run because of unstable borehole conditions. Although the total depth of the hole is 1285 metres below seafl oor (mbsf), the depth range for in situ measurements was limited by the length of the wireline (1018 mbsf) and by the nullifi cation of some geophysical logs due to the presence of steel casing. A depth correction was derived to account for systematic discrepancies in depth between downhole measurements and cores; consequently, log responses can be directly compared to core properties. The resulting data are amenable to studies of cyclicity and climate, heat fl ux and fl uid fl ow, and structure and stress. When integrated with physical properties and fractures measured on the core, this information should play a signifi cant role in addressing many of the scientifi c objectives of the