A canadian geophysical logging system for scientific drilling

在试图理解许多地质现象时，工程师和科学家首先使用一些地面工具，如测绘和地球物理成像来推断地质结构和岩性。 然而，地面技术并不总是能提供所需的信息;工人们必须通过钻探和取芯来解决这个问题。 一个很好的例子，在哪里取芯是必要的，是在恢复质量湖泊沉积物，然后由沉积学家，孢粉学家和古地磁学家研究，以揭示线索，地球的气候变化，通过第四纪。 另一个不同但重要的例子是获得关于构造应力、温度和流体饱和度等真实的原地物理条件的信息。 因此，地球科学家越来越多地转向科学钻探，以解决无法以其他方式解决的问题。 这项工作的大部分是通过综合大洋钻探计划和国际大陆钻探计划等组织在国际上推动的，这两个组织都依赖加拿大的专门知识。 地球物理测井是任何科学钻探的关键组成部分，是指测量原位物理性质，如电导率或沿井眼沿着深度的条件（如温度）。从技术上讲，这是通过使用称为钢丝绳的长钢丝绳将仪器下放到钻孔中来完成的。这些资料对于协助解释岩芯至关重要。在无法恢复核心的情况下，日志记录是绝对必要的。 这里所要求的设备将为加拿大学术地球科学界带来大量的地球物理测井能力，用于科学钻探方案。 除了许多测量电阻率和地震波速度的标准仪器外，此处要求的（即仪器）包括精细分辨磁化率的能力（用于湖泊古气候研究）和流体采样器（从深处取水，用于水文和地球化学研究），以及一台超声波钻孔电视机，用于对钻孔形状进行成像，来确定裂缝的方向，并帮助确定岩心的方向。

In attempting to understand many geological phenomena, engineers and scientists first employ a number of surface tools such as mapping and geophysical imaging to infer geological structure and lithology. However, surface techniques cannot always provide the information desired; and workers must then attack the problem by drilling and coring. One good example of where coring is necessary is in the recovery of quality lake sediments that are then studied by sedimentologists, palynologists, and paleomagneticists to reveal clues to the variations of earth's climate through the Quaternary. A different, but important, example is to obtain information on the true in situ physical conditions of tectonic stress, temperature, and fluid saturation. As such, earth scientists have increasingly turned to scientific drilling to address issues that cannot be resolved any other way. Much of this work is promoted internationally through organizations such as the Integrated Ocean Drilling Program and the International Continental Drilling Program, both of which have relied on Canadian expertise. Geophysical logging, a key component of any scientific drilling, refers to the measurement of the in situ physical properties such as electrical conductivity or of conditions (e.g. temperature) with depth along the borehole. Technically, this is done by lowering instruments into the borehole using a long steel cable called a wireline. Such information is critical in order to assist in the interpretation of the core. In cases where core cannot be recovered logging is absolutely essential. The equipment requested here will bring a substantial geophysical logging capability to the Canadian academic geoscience community for use in scientific drilling programs. In addition to many standard instruments to measure electrical resistivity and seismic wave velocities, the more specialized downhole 'tools' (i.e. instruments) requested here include the capacity to finely resolve magnetic susceptibility (for use in lake paleoclimate studies) and a fluid sampler (to obtain water from depth for hydrological and geochemical studies), and an ultrasonic borehole televiewer to image the borehole shape, to orient fractures, and to assist in orienting core.