Feasibility Study for the Geoprops ODP Probe: In-Situ Measurements of Physical Properties

地球科学各个方面的量化产生了对诸如物理性质、机械状态参数和化学成分等量的准确测量的日益增长的需求。ODP孔越来越被认为是环境条件和岩性记录的重要探测手段。有多种技术可用于测量ODP孔中所需的数量，但事实证明，大多数技术在中等固结沉积物部分的测量效果很差，因为中等固结沉积物在钻井进尺中所占的比例越来越大。在JOI/Ussac关于消耗臭氧层物质中的物理性质的研讨会上，这一关切得到了解决，并提出了一项关于开发导航钻/Geoprops概念的建议。在这一概念中，用泥浆马达驱动的取心钻头和钻具在主钻头前方5米处钻出一个3 3/4英寸的井。这种NaviDrill组件可以在砂线上收回，Geoprops探头可以快速放置在小洞中，Geoprops探头是一个带有封隔器和传感器阵列的内部记录系统。保守的初始设计设想测量温度、孔压。渗透率、应力方向和孔隙流体组成，但如果这一概念成功，可以增加其他测量。在建造Geoprops探测器之前，有必要进行可行性研究，以确保这种方法的必要性和适用性，概述科学和工程方面的限制，并制定总体布局。该奖项将支持这样一项研究。

The quantification of all aspects of the geosciences is creating a growing demand for accurate measurements of such quantities as physical properties, mechanical state parameters, and chemical compositions. ODP holes are becoming increasingly recognized as important probes of environmental conditions as well as records of lithology. Various techniques are available for measurements of the desired quantities in ODP holes, but most of these have proved to be poor in sections of moderately consolidated sediments, which comprise an ever increasing percentage of footage drilled. At the JOI/USSAC workshop on Physical Properties in ODP, this concern was addressed and a recommendation a made to develop the Navidrill/Geoprops concept. In this concept, a 3 3/4" hole is drilled 5 m ahead of the main bit with a mud-motor drive core bit and barrel. This Navidrill assembly can be withdrawn on a sand line and Geoprops probe, an internally recording system with packers and an array of sensors, can be quickly placed in the small hole. A conservative initial design envisages measurements of temperature, pore pressure. permeability, stress orientation and pore fluid composition, but other measurements could be added if the concept is successful. Before construction of the Geoprops probe, a feasibility study is necessary to insure the need for and suitability of such an approach, to outline the scientific and engineering constraints, and to develop a general layout. This award will support such a study.