地球物理测量钻孔的标准指南.中子

详细信息   

• 中文主题词：钻井 ; 地球物理学 ; 中子
• 标准号：ASTM D6727-2001(2007)
• 发布日期：2001
• 英文题名：Standard Guide for Conducting Borehole Geophysical LoggingNeutron
• 英文主题词：borehole geophysics ; neutron log ; neutron porosity log ; well construction ; well logging ; Access tubes ; Borehole geophysical logging ; Caissons ; Engineering criteria/design--soil/rock/related materials ; Geological investigations ; Geophysical investigations/geophysics ; Geotechnical engineering materials/processes ; Ground water ; Hydrogeologic models/investigations ; Lithology ; Logging ; Neutron porosity log ; Water quality monitoring ; Well logging
• 标准状态：现行
• 发布单位：US-ASTM
• 国际标准分类号：07.060 (Geology. Meteorology. Hydrology)
• 载体形态：9P.;A4
• 中国标准分类号：A44
• 国别：美国材料与试验协会

文摘

An appropriately developed, documented, and executed guide is essential for the proper collection and application of neutron logs. This guide is to be used in conjunction with Standard Guide D 5753.

The benefits of its use include improving selection of neutron logging methods and equipment; neutron log quality and reliability; usefulness of the neutron log data for subsequent display and interpretation.

This guide applies to commonly used neutron logging methods for geotechnical applications.

It is essential that personnel (see Section 8.3.2, Standard Guide D 5753) consult up-to-date textbooks and reports on the neutron technique, application, and interpretation methods.

1.1 This guide is focused on the general procedures necessary to conduct neutron or neutron porosity (hereafter referred to as neutron) logging of boreholes, wells, access tubes, caissons, or shafts (hereafter referred to as boreholes) as commonly applied to geologic, engineering, ground-water and environmental (hereafter referred to as geotechnical) investigations. Neutron soil moisture measurements made using neutron moisture gauges, are excluded. Neutron logging for minerals or petroleum applications is excluded, along with neutron activation logs where gamma spectral detectors are used to characterize the induced gamma activity of minerals exposed to neutron radiation.

1.2 This guide defines a neutron log as a record of the rate at which thermal and epithermal neutrons are scattered back to one or more detectors located on a probe adjacent to a neutron source.

1.2.1 Induction logs are treated quantitatively and should be interpreted with other logs and data whenever possible.

1.2.2 Neutron logs are commonly used to: ( 1) delineate lithology, and (2) indicate the water-filled porosity of formations (see Fig. 1).

1.3 This guide is restricted to neutron logging with nuclear counters consisting of scintillation detectors (crystals coupled with photomultiplier tubes), or to He³-tube detectors with or without Cd foil covers or coatings to exclude thermalized neutrons.

1.4 This guide provides an overview of neutron logging including: (1) general procedures; ( 2) specific documentation; (3) calibration and standardization, and (4) log quality and interpretation.

1.5 To obtain additional information on neutron logs see References section in this guide.

1.6 This guide is to be used in conjunction with Standard Guide D 5753.

1.7 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This guide should not be used as a sole criterion for neutron logging and does not replace education, experience, and professional judgment. Neutron logging procedures should be adapted to meet the needs of a range of applications and stated in general terms so that flexibility or innovation are not suppressed. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged without consideration of a project''s many unique aspects. The word standard in the title of this document means that the document has been approved through the ASTM consensus process.

1.8 The geotechnical industry uses English or SI units. The neutron log is typically recorded in units of counts per second (cps) or in percent porosity.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use. The use of radioactive sources in ......