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表面工具，如测绘和地球物理成像来推断地质结构和岩性。然而，表面技术并不总能提供所需的信息；工人们必须通过钻井和取心来解决这个问题。需要取芯的一个很好的例子是，提取优质湖泊沉积物，然后由沉积学家、孢粉学家和古地磁学家进行研究，以揭示第四纪地球气候变化的线索。另一个不同但重要的例子是获取有关构造应力、温度和流体饱和度的真实原位物理条件的信息。因此，地球科学家越来越多地转向科学钻探来解决其他任何方式都无法解决的问题。这项工作的大部分都是通过诸如综合海洋钻井计划和国际大陆钻井计划等组织在国际上推广的，这两个组织都依赖于加拿大的专业知识。地球物理测井是任何科学钻探的关键组成部分，它指的是测量现场物理性质，如电导率或沿钻孔深度的条件（如温度）。从技术上讲，这是通过使用一种称为钢丝绳的长钢缆将仪器放入井中来完成的。这些信息对于帮助解释核是至关重要的。在无法恢复岩心的情况下，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社区带来大量的地球物理测井能力，用于科学钻探计划。除了测量电阻率和地震波速度的许多标准仪器外，这里要求的更专业的井下“工具”（即仪器）还包括精细分解磁化率的能力（用于湖泊古气候研究）和流体采样器（用于水文和地球化学研究从深处获取水），以及超声波井眼电视，用于成像井眼形状，定向裂缝，并协助定位岩心。

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.