School of Petroleum Engineering
University of New South Wales
PTRL3012/PTRL5003 WELL PRESSURE TESTING
November 2009
Time allowed - 2 hours
Total number of questions is 5. You are required to attempt 4 questions.
All questions are of equal value.
Read all

Acoustic Logs
P and S Waves
Porosity from Acoustic Logs
Wyllie formula:
Consolidated rocks
sonic
tlog tm
t t
m
f
Unconsolidated Rocks
sonic
tlog tm 1
t t C
m
p
f
Raymer-Hunt formula
1
sonic (1 sonic ) 2
tlog t f
tm
Cp
tshale C
100
Matrix tr

Formation Evaluation
S2 2016
Session 2, Dr Hamid Roshan
Spontaneous Potential and
Resistivity Logs
SP Logs
The Spontaneous Potential (SP) log was one of
the earliest electric log used in petroleum
industry.
Use of SP log:
detect permeable beds
detect bo

Mechanical Properties of Rocks
and Pore Pressure Prediction
from geophysical logs
Pore pressure
Zoback: Reservoir geomechanics
z
PPhydro w ( z ) gdz w zw g
0
Note
Pore pressure can exceed hydrostatic pressure
in confined formations at depth however the
u

Gamma Ray and Porosity Logs
Gamma Ray and Spectral Gamma
Ray Logs
Gamma Ray Logs
It measures the natural radioactivity of the
formation.
Shale free sandstones and carbonates have
low concentration of radioactive materials and
can be differentiate from s

Logging:
Open hole
Cased hole
Logging
Three general type of logging:
Resistivity/conductivity: natural and artificial
Acoustic
Radioactive: passive and active
What is obtained from well-logging?
Zone correlation
Structure and Isopach mapping
Defin

z3463710
Marcus Carnovale
PTRL3023 (Formation evaluation)
Assignment 1
Questi on 1: Identi fy the shale baseline for SP log and explain your
interpretati on (not more than 6 lines).
To identify the shale baseline on the SP curve, the first step is to look

PTRL5003/PTRL3023
Well Pressure Testing
By: Dilip Kale
Semester 2-2016
Chapter 4
SKIN AND WELLBORE STORAGE
Skin Factor
Wellbore measured pressure is
different than the one calculated
with any idealized mathematical
solution because of:
Formation Damage

PTRL5003/PTRL3023
Well Pressure Testing
By: Dilip Kale
Semester 2- 2016
Solution of Fundamental Flow Equations
Constant Rate, Infinite Reservoir with
Vanishingly Small Wellbore Radius - Line
Source Solution
Constant Rate, Infinite Reservoir with
Finite

PTRL5003/PTRL3023
Well Pressure Testing
By: Dilip Kale
Semester 2-2016
Chapter 5
PRESSURE DRAWDOWN FOR
A VARIABLE RATE WELL
Fixed vs. Multi-rate
Single Rate
Test
Multi-rate
Reservoir
Principal of Superposition
Summation of all the individual parts that c

PTRL5003/PTRL3023
Well Pressure Testing
By: Dilip Kale
Semester 2 - 2016
Recommended Reading
Dake, L P,
Fundamentals of Reservoir Engineering
Elsevier 1978.
Earlougher, R C,
Advances in Well Test Analysis, 1977.
Lee, J, Well Testing, 1982.
Amanat U Chaudh

PTRL5003/3023
WELL PRESSURE TEST ANALYSIS
by
Val Pinczewski
School of Petroleum Engineering
University of New South Wales
Sydney NSW 2052.
AUSTRALIA
July 2015
Prepared for
School of Petroleum Engineering
UNSW
Rev: 28 January 2012
IMPORTANT NOTICE
2012 Uni

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E?
| |
11 qo acting for time tn t0
Aqg : qg ql acting for time tn t1
qu : qj qj_1 acting for time tn j_1
Ag : q qn_1 acting for time tn tn_1
Where qo : 0 and to = 0 and the subscript, 3' runs j : Ln.
The pressure drawdown for step rate change qu : qj

Problem 6.3 Analysis of a variable rate pressure buildup test
(i)
Therefore, the formation permeability and skin factor would be,
k = 9.9 md
s = 1.6
The calculated values are close enough to the previous testing results which the permeability was
10.6 md

Problem 7.1 Semi-log analysis of a constant rate pressure drawdown test in the vicinity of a
linear boundary
In order to calculate the dimensionless time at the intersection of MTR line and the double slope
LTR line, we should let the solution for short t

Problem 2.5
Ct=20 x 10-6.psi-1
= 0.3cp
= 0.032
i.)
.
.
k=80md
= 0.21
re=2000ft
.eqn 1
For t < te the reservoir is said to be infinite acting
replacing ri by re and solving for t to get
2000 =
80
0.032
0.21 0.3 20 106
4 106 = 1.024 103
5.04
0.08192
=

Problem 4.5 Semi-log analysis of pressure drawdown test
Calculate the pressure derivative as shown previously and prepare a log-log plot of the derivative
vs. time. Since the initial pressure is constant, the pressure derivative may be calculated using
ac

Problem 4.7 Semi-log analysis of pressure drawdown test
(i)
Calculate the pressure derivative as shown previously and prepare a log-log plot of the derivative
vs. time. Since the initial pressure is constant, the pressure derivative may be calculated usin

Problem 5.1 Calculation of Multi-Well Pressure Drawdown
Therefore, the total pressure drawdown due to well A at A would be:
The total pressure drawdown due to well B at A would be:
The total pressure drawdown due to well C at A would be:
Therefore,
By Ei-

Problem 4.8 Pressure derivative analysis of pressure drawdown test
(i)
Comparing to the previously used semi-log method for test data DDPT4A.prn
(ii)
Comparing to the previously used semi-log method for test data DDPT4.prn
Comparing with the previously us