PETE 3036
Well Logging
Fall 2016
-porosity
-permeability
+relative
+absolute
-type of fluid
-HC Comp
-size of reservoir
Well Logging
PETE 3036
-saturation
-depth/pay zone ?
-pressure
-temperature
-type of rock
-well surveying/diameter
Instructor: Dr. Dahi
Office: OFB, Rm. 139
Email: a_dahi@lsu.edu
Office Hours: W 2:30-3:30
Class: T-Th 1:30- 2:50 PM
PETE 3036 - Well Logging
Graduate Assistant: Mr. Juan Bautista
Help sessions with Mr. Bautista
Homeworks will be assigned, then
explained in class with answers given. They
may or may not be graded. Quiz are mainly
(not necessarily) based on the previous
homework.
DocScan - converts picture from phone to pdf
Program Educational Objectives
The program educational objectives of the BS program in
Petroleum Engineering at LSU are to produce graduates, who
within 2-5 years after graduation and for the remainder of their
careers are able to:
1. Perform as engineering professionals in the upstream oil and gas
industry, including academia and government, and succeed in
leadership, research, operational and technical roles
2. Identify opportunities, solve open ended engineering problems and
make decisions and plans in the presence of uncertainty utilizing
appropriate engineering and design principles
3. Effectively convey information, including technical concepts,
risks, and recommendations, to and from peers, employers and
employees, and the public
4. Demonstrate a high standard of professional ethics throughout their
careers
Course Materials
Theory, Measurement and Interpretation
of Well Logs by Zaki Bassiouni
Textbook 2: Openhole Log Analysis and
Formation Evaluation, Second Edition
Logs from SL 195 QQ # 98 Provided by
Schlumberger and Helis Oil and Gas
Slides from Lectures Will be posted on
Moodle
-bring logs from SL to exam (do not write in them)
Recommended Reading Material
Schlumberger Log Interpretation
Principles/Applications
Basic Well Log Analysis, Second Edition
By George Asquith and Daniel Krygowski,
AAPG Methods in Exploration No. 16
Introduction to Wireline Log Analysis
(Baker Atlas)
Ground Rules
Leaving Lecture
Cannot come back
No side conversations
No eating/drinking in the class
Turn off cell phones, pagers, Blackberrys
No Talking No newspaper /magazine
reading During Lecture
Questions Encouraged During Lecture
Ground Rules
Office Hours based on posted schedule
Be prepared to answer questions about
homework and reading assignments
Honesty in exams and assignments is
expected and assumed. Infractions will be
dealt with.
Medical excuses need documentation.
Absences for band, sports, etc. must be
arranged in advance
Learnings from Previous Classes
Mistakes in reading scales
Mistakes in calculations
Solving the wrong problem
Using the wrong log header information
Not coming to class
Not using the homework as practice
opportunity
PETE 3036 Course Grades
Quizzes
Homework
Midterm
Final
5%
15%
40%
40%
Homework and Quizzes
Short quiz covering the material taught that
day or the due homework
Grading criteria:
Answering the question that was asked
Showing the work that was requested
(including plots, etc)
The right answer
PETE 3036 Mathematics
Log-Log and Semi-Log Plots
Exponential Equations
Deriving equations from plots of data
Necessary to understand the basis for
resistivity logging
WinSauer et al - 1952
30 Samples
Different Wells
Different Ages
Depth of 10,700
Known as
Humble
equation
Approximation
PETE 3036 - Mathematics
Department Policy: Only
TI-36X Pro calculator is
allowed in the quiz and
exams!
NCEES approved
calculator.
Plan accordingly! No
exception
Formation Evaluation
Purpose: Determine properties of interest that are
required to determine size and value of
hydrocarbon reservoirs, and to develop a plan to
recover these hydrocarbons
Properties include: porosity, permeability, pore
size distribution, compressibility, thickness,
percentage of pore space filled by various fluids
(saturations)
Some properties cannot be measured directly, but
can be related to other measurements (example
hydrocarbon saturation is related to electrical
resistivity) 7758*oil saturation*porosity*thickness*area/(formation oil factor)
OOIP = 7758 So . . h . area/Bo (Original Oil In Place)
*direct measurement, i.e. temperature
*indirect measurement, i.e. porosity
FORMATION EVALUATION
TECHNIQUES
Core Analysis
Fluid Analysis
Pressure and Flow Test
Well Logging
Logging while drilling (LWD)
Electric line logging
Open hole logging
Cased hole logging
-cant run resistivity logs in cased hole logging due to conductivity of metal casing?
-no hydrocarbons flowing outside of the casing, plox = otherwise underground blowout
ADVANTAGES OF WELL LOGS
Obtain large amount of data in relatively
short time.
Reasonable cost.
In-situ measurement of formation
properties.
Determine where other tests should be
conducted.
SHORTCOMINGS OF WELL LOGS
Indirect measurement of needed
parameters.
Need for involved interpretation
techniques.
USERS OF WELL LOGS IN THE
PETROLEUM INDUSTRY
Exploration Geologists
depositional environment
Development Geologist
maps
cross-sections
Drilling Engineer
abnormal pressure detection = know core pressure
fracture gradient = to avoid fracturing well log?
pore pressure
USERS OF WELL LOGS IN THE
PETROLEUM INDUSTRY (cont.)
Geophysicist
-Aid in seismic interpretation
Production Engineer
recompletions
workovers
perforations
Reservoir Engineer
reserve and permeability estimates
Log Analyst
Most critical use by a specially
trained scientist or engineer
green = hydrocarbons
blue = water
Information from Well Logs
Thickness of hydrocarbon reservoirs
Lithology
Porosity
Fluid types
Hydrocarbon saturation
Log Interpretation
Define the problem
What is the water saturation at 21000 feet?
Decide what model to use
Archie equation Sw = (a Rw/
m R )1/n
t
Determine variables required (a, m, n, Rw)
from cores, fluid samples, regional trends,
etc.
Read the relevant data from the logs ( Rt , )
Make corrections if required
Solve for the desired parameter (Sw)
