2. Introduction
Well logging
Types of Well Logging
Electrical Logging
Types of Electrical Logging
Spontaneous Potential Logging
Resistivity Logging
Induction Logging
Conclusion
References
3. IntroductIon
•Geophysical exploration-study of physical
properties Geological materials by using appropriate
instruments
•Types of geophysical exploration:
•Electrical
•Magnetic
•Gravity
•Seismic
•Radioactive and
•Well logging
4. Well loggIng
Continuous recording of a physical parameter of the
formation with depth by introducing sonde
First developed by Schlumberger brothers in 1927
To identify the productive zone of hydrocarbon and
its mobility
To define petrophysical parameters
To determine depth, thickness, formation
temperature and pressure of reservoir
To distinguish between oil, gas and water zones in a
reservoir
5. Types of well logging
Electrical method
Radioactivity method
Sonic logging
Miscellaneous logging
6. electrIc loggIng
Continuous record of the electrical properties
of the fluids and geologic materials
Performed by measuring current through
electrodes in the logging device or sonde
Used in geological investigations to assess the
variation with depth of geologic materials and
associated fluids
Correlate and determine the continuity of
geologic strata
Types- Resistivity, Spontaneous(Self) Potential,
Induction logging
7. Spontaneous Potential Logging
Due to salinity between formation water and mud
filtrate against permeable beds
The measurement is made through a
potential meter
Useful in Establishing correlation of beds from
well to well
To determine bed boundaries and thickness
To evaluate the formation water resistivity
To delineate porous and permeable reservoir rock
8.
9.
10. Resistivity Logging
oAbility to impede the flow of electric current
oFall in the range from 0.2 to 100 ohm meter
o4 electrodes are used
oCarried out by lowering of electrodes
oTypes
Normal and Lateral logs
Laterolog
Microlog
Microlaterolog
Proximity
11. Normal and Lateral log
4 electrodes-2 potential(M and N), 2 power
electrodes(A and B)
Normal device- A and M are closely spaced ,
B is grounded and N is far away from A-M
Lateral device- M and N closely spaced with
electrode A
12.
13. Microlog
The resistivity of a small volume of formation
3 electrodes(A, M1 and M2) in vertical line
Spacing is 1 inch( 2.5cm)
Excellent permeability indicator
14. Microlaterolog
Central electrode very small size and 3 circular
electreodes concentric with 1-2 cm
Accurate estimate of flushed zone resistivity and
hence porosity
15. Proximity log
Used with other resistivity logs
Evaluate permeable zones exhibiting thick (up to
2 cm) mud cakes
16. Induction Logging
In dry boreholes or boreholes containing
nonconducting fluids
Based electromagnetic induction
Parameter is conductivity
Transmitter coil and receiver coil coaxially
supported by an insulating mandrel
22. Well logging technique is one of the type used in
geophysical exploration
This can be performed by logging devices or SONDE
Electrical logging can be done by measuring current
through electrodes in the logging device
Spontaneous potential, resistivity and induction logging
To identify productive zone of hydrocarbon, to define
petrophysical parameter, to determine depth,
formation temperature and pressure of a reservoir, to
measure hydrocarbon mobility
Conclusion
23. References
M.G. Ramachandra Rao,
Outlines of Geophysical prospecting (1975)
Prasaranga Manasagangotri Mysore pp:343-366
1981,Milton B Dobrin, Introduction to
geophysical prospecting , Third edition,
Mcgraw- HILL Book Company pp:568-622
www.wikipedia.com
www.greatgeophysics.com/logginginfo.html
www.geologging.com/english/products/.../ele tric_log.htm