Evaluacion de Formaciones
Evaluacion de Formaciones
Evaluacion de Formaciones
PETROLEO
FORMATION EVALUATION
EVALUACIN DE FORMCIONES
BIBLIOGRAFA
Asquith, G. B., Gibson, Ch., 1982. Basic Well Log Analysis for Geologists. Methods in Exploration. AAPG.
Tulsa Oklahoma.
Asquith, G. B., Log Evaluation for Shaly Sandstones Reservoirs. Continuinig Education Series No 31.
AAPG. Tulsa Oklahoma.
Asquith, G. B., 1985. Handbook of Log Evaluation Techniques for Carboantes Reservoirs. Methods in
Exploration No 5. AAPG. Tulsa Oklahoma.
Bendek, J.,1992. Perfiles Elctricos, una herramienta para la Evaluacin de Formaciones. Asociacin
Colombiana de Geologos y Geofsicos del Petrleo.
Coates R.G., Xiao L, Prammer M. 1999 NMR logging. Principles and Applications Halliburton Energy
services, Houston , Texas
Dewan J. T., 1983, Essential of Modern Hole Log Interpretation. PennWell Publishing Company. Tulsa
Oklahoma.
Foster N. H., 1999, Formation Evaluation I. Treatise of Petroleum Geology. Reprint Series No 16. AAPG,
Tulsa, Oklahoma.
Foster N. H., 1999, Formation Evaluation II. Treatise of Petroleum Geology. Reprint Series No 17. AAPG,
Tulsa, Oklahoma.
Hilchie D.W.,1989 Advanced Well Log Interpretation. Douglas W. Hilchie Inc. Boulder
EVALUACIN DE FORMCIONES
BIBLIOGRAFA
Merkel R.H.,1979, Well Log Formation Evaluation, Continuing Education Course Notes Series No
31, AAPG. Tulsa, OKlahoma
Schlumberger, 1985, A Wellsite guide to the recognition of low resistivity pay sands in the Gulf of
Mexico.
EVALUACION DE FORMACIONES
PROGRAMA
1 Evaluacin de Formaciones
1.1 Introduccin.
1.2 Registros Elctricos
1.2.1 Principios Elctricos
1.2.2 Principios de Interpretacin de Registros Elctricos.
1.3 Registro Litolgico
1.4 Registro Continuo de Hidrocarburos (Mud Logging)
1.5 Registro de Potencial Espontneo (SP)
1.5.1 Calculo de Rw a partir de la curva de SP
1.6 Registros que miden resisitividad
1.6.1 No Enfocados
1.6.1.1 Centralizados
1.6.1.1.1 Normal Corto 16. Rxo
1.6.1.1.2 Normal Largo 64. Rt
1.6.1.1.3 Lateral de 19 pies. (Rt)
1.6.1.2 De Contacto
1.6.1.2.1 Microlog (Rxo)
1.6.1.2.2 Perfil de Buzamiento (Dipmeter)
EVALUACION DE FORMACIONES
PROGRAMA
1.6.2 Enfocados
1.6.2.1Centralizados
1.6.2.1.1Lateroperfiles (Laterologs), LL3, LL7,LL8, DLL.
1.6.2.2 De Contacto
1.6.2.2.1 Microlaterolog, Proximity, MSFL (Rxo).
1.7 Herramientas que miden conductividad
1.7.1Registro de Induccin. 6FF28, 6FF40, ISF, DIL, Phasor
1.7.1.1 Perfiles de Invasin.
1.2.1.2 Rwa
1.8 Herramientas Acsticas
1.3.1 Registro Snico. BHC, LSS.
1.3.1.1 Calculo de Porosidad Snica
1.3.1.2 Cross Plot Delta T vs Resistividad
1.3.1.3 Registro de Velocidad.
1.3.1.3.1 Check Shot
1.3.1.3.2 Vertical Seismic Profile (VSP)
1.3.1.3.3 Offset seismic profiles
EVALUACION DE FORMACIONES
PROGRAMA
1.9 Herramientas Radioactivas
1.9.1 Miden Rayos Gama Naturales. GR; NGR.
1.9.1.1 Calculo del Volumen de Arcilla (V clay)
1.9.2 Miden Rayos Gama Inducidos por Rayos Gamma
1.9.2.1 Registro de Densidad. Calculo de Porosidad
1.9.3 Miden Neutrones Inducidos por R.G. o Neutrones
1.9.3.1 Registro de Neutron. Calculo de Porosidad
1.9.4 Porosidad efectiva.
1.10 Determinacion de Ambientes Sedimentarios a partir de Registros
de Pozo.
1.11 Mecanica de rocas.
1.12 Herramientas para el nuevo siglo (Resonancia Magntica, Cast,
Emi, Rmt (reservoir monitoring tool) etc.
1.13 Transmicion tiempo Real
PETROPHYSICS
Formation and reservoir evaluation
Introduction
Goals
Show that any formation and reservoir
evaluation must respond to the following
questions :
Detection and location of reservoir
Evaluation of their volume
- Thickness
Fluid nature determination
Hydrocarbon volume evaluation
- Effective porosity
- Hydrocarbon saturation
Reservoir productiveness evaluation
- Reservoir permeability
- Reservoir pressure
Economic potential
- Development cost
Oil
Water contact
Oil
Water contact
Oil
Water contact
Gas
Oil contact
Oil
Water contact
Introduction
Petrophysics is the study of the physical
properties of reservoir rocks
Study of physical principles on which are based the
logging tools which measure the petrophysical
properties of rocks
Analysis of the measurements recorded in the wells,
focusing fundamentally on reservoir intervals
Formation and Reservoir evaluation in terms of :
porosity
permeability
volume of fluids in place and producible
General Comments
It would be convenient to never forget that all those physical measurements are
recorded to describe, study and evaluate the economic potential of the rocks
forming the subsurface.
Dry wells
23 dry wells
Oil wells
53 oil wells
Berg, 1968
Formation evaluation
Definition:
The process of evaluating gas- or oil-bearing formations, and of appraising
their commercial significance
It corresponds to the following steps:
determine the petrophysical properties of reservoir rocks,
evaluate their volume and the nature of their content in gas or oil,
estimate their economical potential.
This evaluation implies the study of all the available data that are of :
- different origins and natures,
- obtained at different scales,
linking constantly the observations made at one scale to those made at
another scale.
Scaling down
Origin
of data
Scale
Reservoir
Definition
A reservoir is a volume
of rock that has sufficient
porosity and permeability
to permit the
accumulation of crude oil
or natural gas under
adequate trap
conditions
Reservoir
Reservoir
Reservoir
Reservoir
bed
bed
ELECTRICAL PRINCIPLES
IAB
IAB
Rock of resistance r
A
+
Voltmeter
Resistivity definition
r R
l
A
A
r is the resistance
R is the resistivity
l is the length of the rock
A is the area of the rock cylinder
Rock of
resistivity
R
LOG INTERPRETATION
PRINCIPLES
Direction of
transport stream
Serra 2002
Depend fundamentally on :
- porosity
- permeability
- fluid content
- mineral and elemental composition
Porosity types :
- Total porosity : it is equal to the ratio of the
total volume of void space (pores, canal, vugs,
) existing between the solid elements of a
rock, to the total rock volume :
Phit = (Vt Vs)/Vt = Vp/Vt
It includes:
- the primary porosity, Phi1, which is the
porosity that developed during the final stages
of sedimentation or that was present within
sedimentary particles at the time of deposition
- the secondary porosity, Phi2, which is the
porosity developed in a rock after its
deposition or emplacement, through such
processes as solution or fracturing
Secondary porosity
Primary porosity
Porosity
Intergranular Porosity
Moldic Porosity
Fracture Porosity
Permeability
Q = k(1/m)(A/h)(P1-P2)
Q : flow, m : viscosity, A : surface, h :
flowing distance, P1 et P2 : upstream and
downstream pressures
Saturation (Sw)
Relative permeabilities
Capillary pressure
air-water (psi)
Permaabilities:
Permeability (k)
Capillary pressure
oil-water (psi)
Saturation
Serra 2002
Saturation
Water wet
grain
water
Oil wet
grain
oil
water
oil
Oil wet
I = Rt/Ro
Saturation Sw
Serra 2002
Temperature determination
Pressure determination
Rm, Rmf, Rmc Determination
Rw Determination
a, m & n Determination
Temperature Determination
(Schlumbergers courtesy)
Porosity, (p.u.)
Formation factor, FR
(Schlumbergers courtesy)
Saturation equations
a Rw
mRt
Archies equation
2 2
Sw
1
V shlam
Rt 1V shlama Rw Rsh
a Rw q RshdRw 2 q Rshd Rw
2
2
2Rshd
Rshd
im
S w
1q
Waxman-Smiths equation
2
S
1 w BQvS w
Rt F *Rw
F*
n
w
tmsnwt
S wb
C
C
C
C
Dual-water model equation t a w S
wb
w
wt
Sources of information
Resolution
10 m
1m
Seismic data
1m
Standard logs
Volume attributes
General external
structure
Major sedimentary
breaks
Idea of the environment
Gross electrobed
thickness
Bulk lithology
Major breaks
1cm
Image data
Cores
Serra 2002
Serra 2002
ECLIPS
Offshore & Land Unit from Baker Atlas
Borehole
model
Geological
model
Tool
model
Reservoir
model
Mathematical
model
Evaluation
Serra 2002
- Vertical
- Deviated
- Horizontal
- Open hole
Drilling mode
- Bit
Drilling fluid
- Air
Mud type
Bottom depth
Invasion Profile
- Cased hole
- Turbine
- Foam
- Mud
- Normal (water based)
- Oil base mud
- With additive (salt, barite, KCl)
- Temperature
- Pressure
- Abrupt
- Progressive
Type of well
(courtesy of Schlumberger)
Hole
Axis
Resistivity
Formation
Mud
Distance
Borehole effects
FLUID MOBILITY :
Serra 2002
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Origin of data
The well logging data may have two origins:
LWD origin, so recorded during the drilling itself, with
problems linked to :
- rate of penetration
- frequency of sampling
Wireline origin, so recorded after drilling with all the problems
linked to this case :
- cave development,
- recording speed variations,
- invasion more or less important.
Turbine
RWOB Tool
Mud
Pressure
Positive
Pulse
Mud pulse siren
Time
Mud
Pressure
Negative
pulse
Time
Siren
Time
MWD/LWD ADVANTAGES:
Petrophysical properties can be recorded before practically
any invasion.
LWD measurements
(courtesy of Schlumberger)
(courtesy of Schlumberger)
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Platform Express
be aware in a
combined equipment
such as triple
combo , the tool
situated at the top
cannot provide any
information
corresponding to the x
meters of the bottom.
So, it is important to
know exactly the
respective measure
point of each tool in the
combination.
(Schlumbergers courtesy)
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Some measurements,
especially the nuclear ones,
start by the acquisition of raw
data which are ultimately
translated into log data. The
transfer equations are often
complexes or empirical.
Thus, in the case of neutronic
measurements, what is really
measured corresponds to
counts per second generated
inside different detectors by
epithermal or thermal neutron
capture, taking into account
slowing down, diffusion or
neutron migration lengths.
Sandstone
Limestone
Dolostone
Origin
Types
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Borehole diameter,
Mud-cake thickness,
Mud salinity,
Mud density,
Temperature,
Pressure,
Formation water salinity,
Bed thickness
(Schlumbergers courtesy)
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Tpl curve
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Calibration steps
Primary calibration standards
Secondary standards
Tertiary standard
Calibrator
straps onto
tool
housing
(Schlumbergers courtesy)
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Serra 2002
of data
of tools used
Set of records Combined tools
Relationship between the actual raw measurement and the
measurements reproduced on the logs
Environmental effects on log quality
Sampling rate
Accuracy and precision of measurements
Quality of calibrations
Vertical resolution of each tool
Depth of investigation
Very thick
Beds
Medium
Thin
Dipmeter
Imagery
0.3
Very thin
Laminae
Stratas (cm)
Thick
100
Thin section
Borehole wall
Thickness (cm)
Standard induction
0.1
ation
g
i
t
s
e
v
of in
h
t
p
e
D
Serra 2002
Measurement alteration
Cave effect
Mudcake effect
Mud effect (barite, KCl, )
Eccentering effect (sonic)
Shoulder bed effects
Temperature and pressure effects
Noise (telluric currents, magnetism, )
Hole
Borehole
model
Geological
model
Tool
model
Reservoir
model
Mathematical
model
Evaluation
Serra 2002
It includes :
The log response equations.
The equations for correction of
environmental effects.
The empirical equations linking the
well logging measurements to the
petrophysical parameters :
Archie and others,
Porosity equations,
Sonic equations, etc.
The uncertainties.
The physical constraints.
Sonic equations
Porosity (p.u.)
Porosity (p.u.)
Average time
Field observation
Aspect ratio
(Schlumbergers courtesy)
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
Rxo
Rt
Rt
De Contacto
Microlog
Dipmeter
SHDT
FMI
Rxo
Enfocados
Centralizados (Serie)
DLL (LLd, LLs)
LL3, LL8, SFL
Rt, Ri
Rt, Ri
De Contacto
MSFL
MLL
Proximity
Rxo,
Rxo, Ri
Ri, Rxo
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
Spontaneous Potential
Hole
axis
Ec = Em + Ej = -K log aw/amf
Hole wall
Mud
Shale
Sand
Sand
Mud-cake
Em = -59.1 log aw/amf
Membrane Potential
Ej = -11.5 log aw/amf Hole wall
Migration Cl
Shale
Porous rock
Shale
Virgin zone
Measurement principle
Sand
Formation
water
Hole
axis
Mud
Flushed zone
Shale
Migration Na+
Filtrate
Shale
Liquid-junction Potential
Spontaneous Potential
Potential and current distribution in
and around an impermeable bed
Rmfe
SSP = -K log ----------Rwe
Spontaneous Potential
Depends on :
Lithology
Presence of clay
Bed thickness
Porosity, permeability, and compaction
of rocks
Fluid salinity
therefore
SP log is used to :
Detect Porous Permeable beds
Evaluate Formation Water salinity
Evaluate Formation Clay content
with memorizer
without memorizer
Main Log
Repeat section
Spontaneous Potential
Change of shale
base line:
unconformity
Doll, 1948
SP shapes
Grain size decrease
Pirson, 1977
Remarks on SP approach
The use of the SP curve does not allow a precise and reliable facies
determination due to the following limits.
- The SP deflection is essentially function of the shale percentage of the
beds that is not sufficient for facies determination.
- The SP deflection depends on salinity contrast between formation water
and mud filtrate. Due to that, in some cases one cannot observe any
deflection while facies changes exist.
- In general, the SP curve is not useful in carbonates.
- The SP curve has a poor vertical resolution.
- The SP curve is sometimes replaced by natural gamma ray curve (GR) but,
in that case other limitations exist.
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
V RI dr
4r
Equipotential
spheres
Current lines
Rxo
Rt
Rt
De Contacto
Microlog
Dipmeter
SHDT
FMI
Rxo
Enfocados
Centralizados (Serie)
DLL (LLd, LLs)
LL3, LL8, SFL
Rt, Ri
Rt, Ri
De Contacto
MSFL
MLL
Proximity
Rxo,
Rxo, Ri
Ri, Rxo
Current Paterns
Recorder
Generator
Spacing
Spacing
Normal principle
Recorder
Spacing
Lateral principle
Lateral
Measure point
Normal: resistivity is taken in the middle O of
the spacing
Lateral or Inverse: middle of MN
Investigation radius
normal
Rxo
Rt
Rt
De Contacto
Microlog
Dipmeter
SHDT
FMI
Rxo
Enfocados
Centralizados (Serie)
DLL (LLd, LLs)
LL3, LL8, SFL
Rt, Ri
Rt, Ri
De Contacto
MSFL
MLL
Proximity
Rxo,
Rxo, Ri
Ri, Rxo
Rxo
Rt
Rt
De Contacto
Microlog
Dipmeter
SHDT
FMI
Rxo
Enfocados
Centralizados (Serie)
DLL (LLd, LLs)
LL3, LL8, SFL
Rt, Ri
Rt, Ri
De Contacto
MSFL
MLL
Proximity
Rxo,
Rxo, Ri
Ri, Rxo
Focused devices
Focused devices
Laterologs:
LL3 (1957) uses a central electrode and two long guard electrodes
Focused devices
Laterologs:
LL7 (1957) uses seven small electrodes
Focused devices
Dual Laterologs: DLL (1972)
Three appropriate depths were chosen and were used to
define the invasion profile well enough to estimate Rt.
The sonde records 2 resistivities:
LLd deep at 35 Hz
(return on electrode B at surface)
Bridle
Fracture
(courtesy of Schlumberger)
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
Induction - principles
Principles of measurement
Induction measurements were
originally intended as a
substitute for laterolog tools in
oil-base mud.
Phase-shift
Electromagnetic field
through the formation
90
Electromagnetic field
detected by the receiver
coil
Received voltage is proportionnal
to the formation conductivity
180
Geometrical factor
Vertical component
Geometrical factor theory defines a response
function that answers the question "where
does the signal come from."
=
Geometrical factor
Radial component
Focalization
For commercial reasons a better vertical resolution and depth of
investigation was needed. Focalization was therefore applied using
additional transmitting and receiver coils.
Here are the results which lead to
first commercial tools in the early
50s. 5FF27, 6FF27, 5FF40,6FF40
Skin effect
The loss in amplitude and change in
phase of an electromagnetic field as it
penetrates into a conductive medium.
The higher the formation resistivity, the
stronger the skin effect
The higher the signal frequency, the
smaller the skin effect
2
2fC
A single emitter
operating at 25, 50
and 100 kHz
2 couples
6 couples working at
2 frequencies.
Overall: 28
measurements
28 measurements
5 curves
Invasion image
Hole
Axis
Resistivity
Formation
Mud
Distance
RAB
Dips
(Schlumbergers courtesy)
Depth (ft)
GR
RAB data
Ring resistivity
Bit resistivity
(Schlumbergers courtesy)
(Schlumbergers courtesy)
(Schlumbergers courtesy)
Electromagnetism (ADEPT)
EPT
Endfire array
ADEPT
Broadside array
(Schlumbergers courtesy)
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
Acoustic measurements
Compressional
waves
Shear
waves
Stoneley
waves
crest
trough
rarefaction
compression
cle
Cy
Undisturbed state
Disturbed state
Compression
stretching
Vm
Plane interface
Mud
Formation
Mud
Formation
Mud
Formation
t1 + t2
t =
2
Mud
Formation
Compressional
wavefront
Mud
Formation
Compressional
headwave
shear
Vc
Sa
lt
Gaz bearing
sandstone
Picketts plot
Water
bearing
sandstone
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
Natural Radioactivity
Probability of emission
per disintegration
Detectors
Energy (MeV)
(Schlumbergers courtesy)
(Schlumbergers courtesy)
Counting rate
Fast activation
Thermal activation
Natural radioactivity
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
As a function of their
energy, photons or rays
interact with nuclei in
three manners :
pair production
Compton scattering
photoelectric absorption
Sonde sketch
Measurement of density, b
Measurement of photoelectric index, Pe
Measurement of hydrogen index
(Schlumbergers courtesy)
Measurement of density, b
Measurement of photoelectric index, Pe
Measurement of hydrogen index (Schlumbergers courtesy)
Spontaneous Potential
Resistivity
Conductivity
Acoustic Measurements
Natural Radioactivity
Density
Index hydrogen : Neutron
Nuclear Magnetic Resonance
Sampling
Well seismics
Neutron paths
Color indicates neutron energy :
red, yellow, green, blue from the
highest to the lowest energy
Inelastic-neutron scattering
Thermal neutron
capture
Activation
Fast-neutron
reaction
Elastic scattering
detector
Scattered neutron
Incident
neutron
Nucleus
Nucleus recoil
Elastic-neutron scattering
Measurement of hydrogen index
(Schlumbergers courtesy)
Energy of
incident
neutrons
Inelasticneutron
scattering
Relative counts
Inelastic spectrum
Fast-neutron reaction
Energy (MeV)
Relative counts
Capture spectrum
Energy (MeV)
Shale
Sandstone
Cave : Shale
Shale
Sandstone
Shale
Sandstone
Shale
Sandstone
Coarsening-up sequence
Determination of lithology
from density and neutron responses
Fluid sampling
MDT de Schlumberger
Measurement of reservoir pressure and permeability
(Schlumbergers courtesy)
Gas
Oil
Water
Slope :
Fluid density
Tison, 1975
SNP
CNL
tc
ts
Pe
tp
2,64
2,13
2,52
2,59
2,53
2,59
2,82
2,86
2,99
2,71
2,85
3,08
3,91
2,35
2,98
2,04
2,79
4,09
5,18
3,59
-1
4
-2
-2
-2
-1
12
-2
2
-3
-2
-3
-1,3
20
38
21
0
1
5,7
12,9
60+
-2
-3
25
0,2
11
60+
56
58
69
88
7,2
90,4
149
4,4-6
4,4-6
4,4-6
4,4-6
6,2-7,9
7-8,2
7-8,2
7-8,2
7-8,5
8,3-9,4
50,8
49
44
224
72
4,8
3,7
7,2
7,4
7,2
4,35
6,7
14
19
13,8
9,0
25,8
56,2
9,4
15
9,5
12
1065
111
47
4,65
47,9
49
1,8
1,8
2,9
2,9
2,9
1,76
2,4
4,8
6,3
5,08
3,16
8,44
14,7
4,0
5,06
4,7
4,3
266,8
21
13
4,8-6
6,8
7,2-8,1
9,1
8,7
4,3
5,0
16
16
16
7,5
17
21
30
7,1
4,7
22
52
19
12
754
24
6,8
101
71
11
0
2
2,1
6,3
50+
-1,2
-2
14
-1
4
50+
84,9
43,8
52
50
67
69,7
42,9
56,9
91
132,7
79,3
102,6
6,8-7,5
4,1
6,3
5,6-6,3
8,8-9,1
6,8
8,4-8,6
7,9-8,4
9,9-11
10,5-11
Log Resolution
Images have the
highest vertical
resolution
They allow detection
of
very small geological
objects,
thin depositional units
and
surfaces.
Acoustic Images
UBI Sonde
Compensating device
Motor assembly
Gear box assembly
Rotating electrical
connection
Centralizer
Rotating shaft with
built-in electronics
Rotating seal
Transducer
Interchangeable
rotating sub
~75 rps
(Schlumbergers courtesy)
Image Comparison
RAB Images
FMI Images
Laminations
Fracture
(Schlumbergers courtesy)
These types of tools allow the sampling of rock at a desired depth. These rock
samples allow a better evaluation of the porosity and permeability, as well as their
mineralogical composition, the clay type and distribution, the grain and pore size
(Schlumbergers courtesy)