ISO/TR 14685:2001 pdf download

ISO/TR 14685:2001 pdf download.Hydrometric determinations -Geophysic allogging of boreholes for hydrogeological purposes -Considerations and guidelines for making measurements.
2.18
filter pack
granular material introduced into a borehole between the aquifer and a screen or perforated lining to prevent or control the movement of particles from the aquifer into the borehole
2.19
fishing tool
grappling equipment used to locate and recover items from within a borehole
2.20
flushed zone
zone at a relatively short radial distance from the borehole immediately behind the mudcake where all of the pore spaces are filled with borehole fluid
2.21
fluid column
that part of a borehole filled with fluid
2.22
formation
geological unit or series of units
2.23
geophysical log
continuous record of a physical or chemical property plotted against depth or time
2.24
grain size
principal dimension of the basic particle making up an aquifer or lithological unit
2.25
grout
cement and water mixture
2.26
header information
description of type of data required for inclusion in a table or as input to a computer program
2.27
invaded zone
portion of formation surrounding a borehole into which drilling fluid has partially penetrated
2.28
jig
calibrating device for logging sondes
2.29
leachate
liquid that has percolated through solid wastes
2.30
lining
tube or wall used to support the sides of a well and sometimes to prevent the entry of water
2.31
lithology
physical character and mineralogical composition that gives rise to the appearance and properties of a rock or sediment
2.32
logging
recording of data
2.33
mud cake
residue deposited on the borehole wall during drilling
2.34
open borehole
unlined borehole
2.35
packer
device placed in a borehole to seal or plug it at a specific point
2.36
permeability
characteristic of a material that determines the rate at which fluids pass through it under the influence of differential pressure
2.37
photomultiplier
electronic device for amplifying and converting light pulses into measurable electrical signals
2.38
plummet
plumb bob used for determining the apparent depth of a borehole
2.39
porosity
ratio of the volume of pore space in a sample to the bulk volume of that sample
2.40
rising main
pipe carrying water from within a well to a point of discharge
2.41
rugosity
degree of roughness (of the borehole wall)
2.42
saline interface
boundary between waters of differing salt content
2.43
saturated zone
that part of earthen material normally beneath the water table in which all voids are filled with water that is under a greater-than-atmospheric pressure
2.44
screen
type of lining tube, with apertures designed to permit the flow of water into a well while preventing the entry of aquifer or filter pack material
2.45
sidewalling
running a log up or down a borehole with the sonde in contact with the borehole wall
In addition to lithological interpretation, a number of physical and chemical properties of the surrounding rock and fluids contained therein can be investigated.
Geophysical logs can be run in all boreholes including those cased with metal or plastic casing and filled with water, brine, mud, drilling foam or air. The greatest return of information is derived from open (uncased) boreholes filled with formation water or mud. In plain-cased boreholes, investigation of the geological formation is limited to the nuclear logs and, with plastics casing, induction logs may also be used. Conventional resistivity logs (especially focused ones) are possible to use in plastic screens.
The wealth of information from geophysical logs means that they can be used in many spheres of hydrogeological investigation; for example, in water resources projects to investigate aquifer hydraulics and distribution of yield within an aquifer of group of aquifers. In the rapidly expanding field of groundwater quality control, geophysical logging is now extensively used to monitor groundwater pollution, to trace leachate movement and to monitor the boundaries between saline interfaces.
Borehole logging is also important in investigating the deep hydraulic and hydrogeological properties of rocks in geothermal and radioactive waste disposal projects. There are a number of engineering applications of geophysical logging for investigating borehole conditions and, where television logging is available, for the inspection of casing and pumps.
Figure 2 shows an example of a composite log where the disposition of aquifers can be seen.
Geophysical logging can be repeated many times in a borehole or series of boreholes at intervals ranging from minutes to years, adding a new dimension to the information obtainable. This is particularly applicable to aquifer hydraulics and recharge and pollution studies.
Geophysical logs also provide information that can be directly used in surface geophysical studies for standardization and calibration of parameters. For example, sonic logs can be calibrated with seismic sections and resistivity logs can be compared with surface electrical resistivity surveys for resistivity standardization.