The Effects of Temperature and Pressure on Absolute Permeability of Sandstones

116 Pages·2002·3.1 MB·English

by  Muhammadu Aruna

Stanford Geothermal Program
Interdisciplinary Research
i n Engineering and Earth Sciences
Stanford University
Stanford, California
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THE EFFECTS OF TEMPERATURE AND PRESSURE ON
ABSOLUTE PERMEABILITY OF SANDSTONES
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by
Muhammadu Aruna
April 1976
This research was carried out
under Research Grant GI-34925
by the National Science Foundation

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ACKNOWLEDGEMENT
The author would like to express his sincere appreci- I
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ation to his adviser, Dr. Henry J. Ramey, Jr., for his in-
struction and guidance throughout the research work. He
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made it possible for the author t o come to Stanford Universily
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and complete his graduate studies successfully. I
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The assistance and practical suggestions from the
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faculty of the Department of Petroleum Engineering, particu-
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larly from Dr. W. E. Brigham and Dr. Sullivan S . Marsden,
are gratefully acknowledged. The cooperation I enjoyed from
the department secretaries, especially from A l i c e Mansouria4,
w i l l not be forgotten. I
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Many thanks are due t o my friends, particularly Rorio
Arihara, H. K. Chen, and Paul Atkinson, for their helpful
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comments and Timely help through the days of experimental w&k.
Credit for mdification of the apparatus built by Wei4
braadt and Cass6 is due Jon Grim, the Petroleum Engineering1
Dezs-tnent machinist.
Finally, Dr. F. Ca.ss6 reviewed this manuscript and ma&
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E?--: ?slpful sugg3stions'.
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?>lis w s ~ kw as fund.ed under National Science Foundatiovl
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pm= '7- GI- 34925.
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This report was prepared originally as a
dissertation sub,mitted to the Department of
Petroleum Engineering and the Committee on the
Graduate Division of Stanford University i n
partial fulfillment of the requirements for the
degree of Doctor of Philosophy.
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DEDICLTED TO MY PARENTS AND
ALL THE GOOD PEOPLE I N MY LIFE
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ABSTUCT
The standard procedurle for determining the permeability
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of porous media according t:o API Code Mo. 27 is based on the
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fundamental assumption that:, as long as viscous f l o w prevails,
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the absolute permeability of a porous medium is a property of
the medium, and is independlent of the fluid used i n its deter-11
mination, s l i p effect being taken into account i n the case of
gas flow. Absolute permeability has, therefore, been traditiod-
ally measured at room conditions, with the assumption that it I
changes only with overburden pressure and not w i t h temperature +
Results obtained at room temperature may then be used to pre-
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dict performance at reservoir conditions after correction for
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reduction by stress effects.
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Although t h i s assumption is true for most fluids, re- I
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sults of recent absolute permeability measurements of water
flow through porous media at high temperatures and high
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overburden pressures differ from room condition values.
only was the absolute permeability t o water at high confining
pressure lower than that to1 other fluids used at room tempera-
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ture, but also, there was a significant permeability reduction
at elevated temperatures.
An existing permeaneter was modified t o enable f l o w of
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different fluids through separate flow lines. Distilled I
water, a white mineral oil, nitropen and 2-octanol were the
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fluids used, and tests were carried out on natural consoli-
dated sandstones and unconsolidated silica sand.
With the exception of water, the absolute permeabilities
of the cores to other fluids showed l i t t l e or no temperature
dependence. The reduction i n permeability t o w a t e r with
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temperature increase was attributed to interaction between
water and silica. In the case of water f l o w through geothermd 1
systems or i n thermal recovery processes which cause large
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changes i n formation temperatures, the effect of temperatures
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on absolute permeability should be considered i n engineering
calculations.
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-TASL E OF CONTENTS
Page
. . . . . . . . . . . . . . . . . . .
ACKNOWLEDGEMENT i v
. . . . . . . . . . . . . . . . . . . . . . .
ABSTRACT, V
. . . . . . . . . . . . . . . . . .
TABLE OF CONTENTS v i i
. . . . . . . . . . . . . . . . . . .
LIST OF TABLES. X
. . . . . . . . . . . . . . . . . . .
LIST OF FIGURES xi
CFAPTERS
. . . . . . . . . . . . . . .
1. INTRODUCTION. 1
. . . . . . . . . . .
2. FLOW I N POROUS YEDIA. 4
. . . . . . . . . . . . .
2.1 Darcy's Law. 4
. . . . . . .
2.2 Darcy's Law for Gas Flow 5 '
. . . . . .
2.3 Slip Phenomena i n G a s Flow 6 1;
. . . . . . . . .
2.4 Visco-Inertial Flow. 7
. . . . . . . . . . . . . . . .
3. LITERATURE. 9
. . . . . . . . . .
4. EXPERIMENTAL EQUIPMENT. 15
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. . . . .
4.1 General Description. 15
. . . . . . . . . . . . .
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4.2 Core Holder. 18 ~'
. . .
4.3 A i r Bath and Temperature Control 18
. . . . . . . .
4.4 Liquid and Gas Sources 20
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4.5 Liq,uid Pumps 21
. . . . . . . . .
4.6 Hydraulic Hand Puny. 21
. . . . . . . . . . .
4.7 Heat Exchangers. 21
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Table of Contents, continued Page
. . . . .
4.8 Backpressure Valve 22
4.9 Flow Rate Measuring Devices. 22
4.9-1 Liquid Flow 22
4.9-2 Gas Flow 23
.
4-10 Pressure Recording Devices 23
. . . . . . . . . . . .
5. PROCEDURE 25
. . . . . .
5.1 Core Preparation 25
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5.1- 1 Consolidated Massillon Sand-
stones 25
5.1-2 Unconsolidated Ottawa Sand 26
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5.2 Establishing Run Conditions. 27
5.3 Measurements and Calculations. 28
5.3- 1 Liquid Flow 28
5.3-2 Gas Flow 37
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6. ANALYSIS OF RESULTS AND DISCUSSION. 4 1
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6.1 Water Flow 4 1
6.1- 1 Consolidated Sandstones 4 1
6.1-2 Unconsolidated Sand 43
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6.2 Gas Flow 48
6.2-1 Consolidated Sandstones 50 3
6.2-2 Unconsolidated Sand 56
. . . . . . . . .
6.3 O i l Flow 56
. . . . . .
6.4 2-Octanol Flow 58
. . . . . . . .
6.5 Discussion 62
7. C ONC LU S IONS AND R.EC OIWENDAT I ONS 65
. . . . . . . . . .
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8. REFERENCES.
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