516 result(s) found.

Ascertaining the location and properties of subsurface lithological layers requires acquisition and interpretation of well logs. Logs can be drawn by hand to reflect lithology as cuttings are pumped to surface; or they can be acquired by wireline logging tools lowered into the well, or while drilling, using specially instrumented drill collars that make up part of the drilling assembly. Interpretation can be carried out by hand, using established log analysis formulae, or by sophisticated computer routines. Formation evaluation is the key to determining whether a well has struck pay, or is just a dry hole. Terms in this discipline range from Archie equation to logging, and from permeability to Z/A effect. All definitions have been reviewed by formation-evaluation experts, and many are accompanied by high-quality photographs or illustrations.

Variables and Numbers

Sor	m	Sw	6FF40
a	n

A

a	activation log	API unit	array sonic
accelerator source	adjacent bed	apparent matrix	attenuation
accuracy	Alford rotation	Archie equation	attenuation resistivity
acid effect	alpha processing	Archie rock	azimuthal
acoustic log	altered zone	armor	azimuthal density
acoustic mode	aluminum activation log	array induction	azimuthal laterolog
acoustic transducer	annulus	array laterolog	azimuthal resolution
acquisition log	antisqueeze	array propagation resistivity

B

backup curve	bit resistivity	bottomhole temperature	broadside array
bad hole	borehole compensation	bound fluid	bucking coil
balanced array	borehole correction	bound water	bucking current
base exchange	borehole gravity	bound-fluid log	bulk relaxation
base log	borehole gravity meter	Boyle's Law	buoyancy method
BHT	borehole televiewer	Boyle's Law Double Cell	butterfly chart
bimetallism	Born method	Boyle's Law Single Cell	button resistivity
Biot theory	bottom log interval	bridle

C

cable	centralizer	Compton scattering	corrected gamma ray
cake	centrifuge	computed tomography	correlate
calibration	channeling	conductive invasion	correlation log
camera	chemical neutron source	conductive rock matrix model	CPMG
capillary pressure curve	clay bound water	conductivity	cross dipole
carbon density	clay-bound water	conductometric titration	cross section
carbonate gamma ray	coding	core	crossplot porosity
cartridge	compatible scales	core analysis	crosswell electromagnetic tomography
cation exchange capacity	compensated density log	core gamma log	crosswell reflection tomography
cation-exchange capacity	compensated neutron log	core image	crosswell seismic tomography
cave effect	compensated-density log	core plug	crosswell tomography
cement bond log	composite log	corkscrew hole	curve
cementation exponent	compressibility

D

data rate	depth correlation	detail log	diffusion relaxation
Dean-Stark extraction	depth datum	diameter of invasion	dip correction
deconvolution	depth derived	diameter of investigation	direct hydrocarbon typing
deep induction	depth mark	dielectric constant	dispersed clay
delta rho	depth matched	dielectric permittivity	distillation extraction
delta t	depth of invasion	dielectric propagation log	drainage
delta t stretch	depth of investigation	dielectric resistivity	drained test
delta-t stretch	depth reference	differential SP	drillpipe conveyed
density measurement	depth wheel	differential spectrum	dual induction
departure curve	depth-derived	diffusion	dual water
dephasing

E

eccentralizer	electrical double layer	electromagnetic propagation	epithermal neutron porosity measurement
echo spacing	electrical log	electromagnetic propagation measurement	equivalent conductance
effective porosity	electrical survey	elemental capture spectroscopy	equivalent water resistivity
effective water saturation	electrode device	endfire array	estimated ultimate recovery
elastic neutron scattering	electrode resistivity	enhanced diffusion	excavation effect
electrical anisotropy	electrokinetic potential	environmental corrections

F

far water	filtrate slump	flushed-zone water saturation	free fluid
fast diffusion	first reading	formation	free induction decay
fast formation	fish	formation evaluation	free water
fast formation arrival	fishing bell	formation exposure time	free-induction decay
fast neutron reaction	flexural mode	formation factor	fresh core
fast-formation arrival	fluoroscopy	formation water	fresh water
fast-neutron reaction	flushed zone	forward modeling	FTIR
filtrate	flushed zone water saturation	Fourier transform infrared spectroscopy	full waveform

G

Gal	gamma-gamma log	GR	guard electrode
gamma ray interactions	geochemical log	grain density	guard log
gamma ray log	geometrical factor	gravity units

H

head	heading	housing	hybrid scale
head wave	horizontal resistivity	Humble formula	hydrogen index

I

ID	induced gamma ray spectroscopy	insert	inverse
IM	induction	in-situ fluid analysis	inverse filter
imbibition	induction electrical survey	interwell tomography	irreducible water
in situ fluid analysis	inelastic neutron scattering	invaded zone	isolated porosity
in situ viscosity evaluation	inertial resistance	invasion	iterative forward modeling

J

J factor

K

K coefficient

L

lag	leaky mode	liquid-junction potential	logging tool
laminated sand	limestone compatible scale	log	logging unit
laser diffraction	limestone porosity unit	logarithmic mean	long spacing sonic log
last reading	limestone-compatible scale	logging	longitudinal relaxation
lateral	liquid saturation method	logging run	long-spacing sonic log

M

m	measurement error	microlaterolog	monopole
magnetic mud	measurement range	microlog	moveable hydrocarbons
magnetic resonance	medium induction	microporosity	moved hydrocarbons
maximum recorded temperature	membrane potential	microresistivity	mud filtrate
measure point	mercury displacement method	microspherical log	mudcake
measurement after drilling	microcylindrical log	minute mark	multiple salinity

N

n	neutron generator	neutron porosity	normal mode
native state core	neutron interactions	NMR	nuclear magnetic resonance
natural gamma ray spectroscopy	neutron log	normal	nuclear magnetic resonance measurement
neutron capture

O

oil wet	oil-wet	oxide closure model	oxide-closure model
oilfield battery

P

pad	phase shift resistivity	pore throat	propagation time
pair production	phase-shift resistivity	porosimeter	proximity log
parallel resistivity	photoelectric effect	porosity exponent	pseudogeometrical factor
pass	Pickett plot	porosity unit	pseudostatic spontaneous potential
PEF	pickup	porous plate technique	PSP
permanent datum	pick-up	potassium	pulse echo
permeameter	play back	precision	pulsed neutron spectroscopy log
permittivity	playback	preserved core	pulsed neutron spectroscopy measurement
perpendicular resistivity	polarization horn	propagation resistivity	pulse-echo
phase shift	polarization time	propagation resistivity measurement

Q

quadrant density

quick look

quicklook

R

R signal	real-time data	reproducibility	restored state core
Rh	recorded data	reservoir quality (RQ)	retort method
Rv	recorder	residual oil	ring resistivity
Rwa	reference point	residual oil saturation	ROS
radial processing	relative dielectric constant	resistive invasion	routine core analysis
radial resolution	relative dielectric permittivity	resistivity	R-signal
radial response	relaxation time	resistivity index	rugose
radius of investigation	remaining oil saturation	resistivity log	rugosity
random error	repeat section	resolution matched	run
real time data	repeatability	response matched

S

sampling error	sidewall	sonde error	standoff
sampling interval	sidewall core	sonic measurement	static spontaneous potential
sandstone compatible scale	sieve analysis	SOR	steady state
sandstone porosity unit	sigma	Soxhlet extractor	step profile
sandstone-compatible scale	skin effect	SP	stick and slip
saturation equation	slow formation	specific permeability	Stoneley permeability
saturation exponent	slowing-down length	spectrum	stress induced anisotropy
saturation unit	slowing-down time	spherical focusing	stress-induced anisotropy
scintillation detector	slowness	spine and ribs plot	structural shale
secondary porosity index	slowness time coherence	spiral borehole	summation of fluids method
secondary-porosity index	slowness-time coherence	spontaneous potential	surrounding bed
shale baseline	small pore water	spreading loss	survey
shifted spectrum	small-pore water	square log	systematic error
shoulder bed	sonde	SSP

T

T1	thermal diffusion length	time-lapse	trace
T2	thermal neutron absorber	tool string	track
tail	thermal neutron porosity measurement	top log interval	transition zone
tapered cutoff	thorium	tornado chart	transmission tomography
telemetry	tick mark	torpedo	transverse relaxation
terrain correction	time after bit	tortuosity	true resistivity
thermal capture	time lapse	total porosity

U

UCS	uncertainty	undrained test	unsteady state
ultra-long spaced electrical log	unconfined compressive strength	uniaxial compressive strength	uranium
ultrasonic measurement	undisturbed zone

V

variable-density log	verification listing	vertical resolution	virgin zone
verification	vertical resistivity	vertical response	volumetric cross section

W

wait time	water wet	well log	whole core
wall cake	water-filled resistivity	wet clay porosity	wireline
water filled resistivity	water-wet	wet-clay porosity	wireline log
water saturation	weak point	wettability

X

X signal	X-ray diffraction	X-ray fluorescence (XRF)	X-signal
X-radiography

Z

Z/A effect