This document provides an overview of well logging. It defines what a well log is, discusses the history of well logging which began in 1927 in France, and describes some of the early logging tools developed from the 1930s through the 1980s. The document also outlines the various uses of well logs for geophysicists, geologists, drilling engineers, reservoir engineers, and production engineers. It compares wireline logging versus logging-while-drilling and discusses some of the advantages and disadvantages of each method. Finally, the document reviews the components typically included in a well log heading.

1. ANALISA LOGGING
SUMUR
Pertemuan Ke-1
Basic Well Log
oleh :
BAGUS ADHITYA
Email: adhityabagus20@gmail.com
Phone: +628567123079

2. Definition
 According to 4th Edition of J.A.Jackson’s
Glossary of Geology:
Log  A continuous record as a function of
depth, usually graphic and plotted to scale on a
narrow paper strip, of observations made on the
rocks and fluids of the geologic section exposed
in the well-bore.

3. Well Log History
 The first electrical log was introduced in 1927 in France using
stationed resistivity method.
 The first commercial electrical resistivity tool in 1929 was
used in Venezuela, USA and Indonesia.
 SP was run along with resistivity first time in 1931
 Schlumberger developed the first continuous recording in
1931
 GR and Neutron logs was started in 1941
 Microresistivity array dipmeter and lateralog were first time
introduced in 1950’s
 The first induction tool was used in 1956 followed by
Formation tester in 1957, Fomation Density in 1960’s,
Electromagnetic tool in 1978 and most of Imaging logs were
developed in 1980’s
 Advanced formation tester was commercialized in early
1990’s

5. A well log.
Representation of the
first “log”
Made at Pechelbronen,
Alsace, France, in 1927
By H Doll

6. USES OF LOGS Geophysicist
• As a Geophysicist what do you look for?
• '' Are the tops where you predicted?
• '' Are the potential zones porous as you have
assumed from seismic data?

7. USES OF LOGS Geologist
• The Geologist may ask:
• '' What depths are the formation tops?
• '' Is the environment suitable for accumulation of
Hydrocarbons?
• '' Is there evidence of Hydrocarbon in this well?
• '' Are Hydrocarbons present in commercial
quantities?
• '' How good a well is ti?
• '' What are the reserves?
• '' Could the formation be commercial?

8. USES OF LOGS Drilling
Engineer
• " What is the hole volume for cementing?
• " Are there any Key-Seats or severe Dog-legs
in the well?
• " Where can you get a good packer seat for
testing?
• “Rate of Penetration of Drill Bit (ROP)
• Analysis of Drill Cutting and Drilling Mud
• Gain or Losses of Drilling Mud

9. USES OF LOGS Reservoir
Engineer
• The Reservoir Engineer needs to know:
• " How thick is the pay zone?
• " How Homogeneous is the section?
• " What is the volume of Hydrocarbon per cubic
metre?
• " Will the well pay-out?

10. USES OF LOGS Production
Engineer
• The Production Engineer is more concerned
with:
• " Where should the well be completed (in what
zone(s))?
• " What kind of production rate can be
expected?
• " Will there be any water production?
• " How should the well be completed?

11. Sources of
Information

12. LOGGING COSTING
 Expensive; 5-10% of total well cost
 Onshore wells (cheaper), a minimum set is run
 Offshore (expensive), full sets of logs are run
 Its run even if hydrocarbons are not found
 Hard gained information

14. Wireline vs LWD

15. WIRELINE: Logging which conducted
after drilling process, sensor run into the
wellbore and transmitting data through
electric cable
LWD: Logging which conducted while
drilling process, sensor run into the
wellbore using drill pipe and transmitting
data through mud pulse
BASIC PRINCIPLE : WIRELINE vs LWD

16. Wireline Logging
Advantage
1. Better Resolution
2. Better Depth Control
3. More certain on Data
Quality
Disadvantage
1. Invasion Effect
2. Unable to Log in High angle
Well (> 60 deg)
3. More Rig Time (Acquired
After Drilling)

17. Logging While Drilling
Advantage
1. Reduce Rig Time
2. Real Time Decisions
3. Minimized Borehole Problems
4. High Angle/Horizontal Wells
Disadvantage
1. Borehole size are not known
2. Good data collected only when the tool is
rotating
3. Log resolution is generally poorer than that of
wireline
4. Depth control is poorer than wireline data

18. REVIEW LOG – HEADING LOG
Calibratio
n Log

19. LOG PRESENTATION - THE HEADING
Well location
Depth references
Well depth
Date of log
Casing shoe depth
Bit size
Mud data
 Type
 Properties
 Resistivities
Max. Temperature

20. Well Log
Log Lithology
 SP Log
 Caliper Log
 GR Log
Log Resistivity
• ILS
• ILM
• ILD
Log Porosity
 RHOB
 NPHI
 DT

21. TERIMA KASIH