Production Enhancement with Acid Stimulation

265 Pages·2008·9.06 MB·English

by  Kalfayan

PRODUCTION
Acid
ENHANCEMENT with
Stimulation
Leonard Kalfayan
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Disclaimer:
The recommendations, advice, descriptions, and the methods in this book are
presented solely for educational purposes. The author and publisher assume no liability
whatsoever for any loss or damage that results from the use of any of the material in
this book. Use of the material in this book is solely at the risk of the user.
Copyright © 2008 by
PennWell Corporation
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Library of Congress Cataloging-in-Publication Data
Kalfayan, Leonard.
Production enhancement with acid stimulation / Leonard Kalfayan.-- 2nd ed.
p. cm.
Includes bibliographical references and index.
ISBN-13: 978-1-59370-139-0
1. Oil wells--Acidization. 2. Gas wells--Acidization. I. Title.
TN871.K284 2007
622’.338--dc22
2007037762
All rights reserved. No part of this book may be reproduced, stored in a retrieval
system, or transcribed in any form or by any means, electronic or mechanical, including
photocopying and recording, without prior written permission of the publisher.
Printed in the United States of America
1 2 3 4 5 12 11 10 09 08
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INTRODUCTION
The history of acidizing dates back to 1895. It is filled with discovery and ingenuity,
as well as spectacular success and disappointing failure. The potential of acidizing for
prolific well stimulation has always been tempered by its unpredictability and by the
continuing frustrations it causes. It cannot and will not be defined by an exact set of
rules and expectations.
Nevertheless, in terms of potential return on investment and generation of
immediate productivity enhancement and cash flow, at a reasonable price, acidizing has
no equal. Unfortunately, this tremendous attribute is largely unappreciated. Acidizing
is often perceived as a treatment of last resort or as a necessary evil when it comes
to remedial well service. It is not often recognized as the high-return, often low-cost
well stimulation process that it is—nor, for example, as an environmentally favorable
alternative to drilling wells in mature fields.
This lack of appreciation for acidizing partly stems from the natural and
predominant oil field preference for drilling and hydraulic fracturing, in particular,
which is, admittedly, more appealing to the masses. What is unfortunate, though, is
that acidizing often is viewed incorrectly as a competing method, rather than as a viable
optional addition to hydraulic fracturing and other stimulation methods. The use of
acids in well stimulation processes has not been fully tapped.
The common frustration with acidizing results mostly from the unending desire to
impart predictability through forced systematization, in order to develop reproducible
treatment designs. This approach can work with fracturing in certain areas. However,
with acidizing, history has shown repeatedly that forced systematization is doomed to
failure and will lead to certain discouragement.
What history has shown is that acidizing is not an exact, predictable science.
Acidizing is an inexact science as well as an art that cannot be completely mastered.
(While some may call it a black art, it is not mysterious to that extent any more.) In
any case, all of the arts are sciences, and much of science is art too, though not always
recognized as such. For example, music is both an art and a complex mathematical
science. Proficiency and enjoyment result as a feel for the art is developed, not from a
full understanding of its complexities. There is always opportunity for experimentation,
new concepts, and new approaches.
The same can be said of acidizing. Complete mastery may not be possible, but it is
also not necessary for success. Furthermore, there can be excitement and satisfaction
in the risk taking and creative possibilities and in the tremendous profit potential that
acid stimulation affords.
There are many written sources of information on acidizing and related subjects.
There are excellent texts covering topics related to stimulation, including acidizing.
There have also been many articles and technical papers on acidizing in the industry
literature. Most of these are sanctioned and published by the Society of Petroleum
Engineers (SPE) in meeting proceedings and in society journals.
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XVIII PRODUCTION ENHANCMENT WITH ACID STIMULATION
This information includes well and field stimulation case histories, specific aspects
of acidizing fundamentals and research, and development of new and improved methods,
products, and novel applications. Meaningful contributions to the industry are made
each year. In addition, there are in-house company guidelines, best practices, and the
like. There is also in-house information available in service companies, oil companies,
and generally throughout the industry.
This book is neither an attempt to supply the industry with a textbook on acidizing
nor a comprehensive compilation of technical contributions to the industry in subjects
related to acidizing. It is also not a simplified acidizing treatment design “cookbook”:
History has shown repeatedly that acidizing cannot be and should not be subject to
cookbook procedures. Only certain steps in the design decision process may be treated
as such, as we will see. With acidizing, there are many more exceptions to the rules than
there are rules. In fact, true success in acidizing is associated with a better understanding
of the exceptions.
This book represents my interest in promoting an appreciation for the art of
acidizing. Its contents are intended to serve as a practical guide when considering the
stimulation decision process, acid treatment design, and acid treatment benefits and
limitations in both carbonate and sandstone formations. Moreover, this book is really
a commentary on what I consider to be of practical importance with respect to acid
treatment design. Certain portions are inspired by and refer to the work of George
King and, in particular, Harry McLeod, who has made tremendous contributions
to the understanding and practice of acid stimulation, especially in sandstones. In
addition, this book has been influenced by several others, including David Watkins,
Roland Krueger, Rick Gdanski, Phil Rae, Kieran O’Driscoll, Gino di Lullo, Syed Ali,
Matt Zielinski, and Kern Smith.
Beyond what is presented here, I hope that you find the interest and curiosity
to explore the texts and the literature. These will allow you to learn more about this
remarkable and extremely profitable, yet often misunderstood and still unappreciated,
area of the well stimulation industry. It is my further hope that your continued research
and investigation will include those works presenting acidizing history and acidizing
mathematics, physics, and chemistry, as well as the latest popular acidizing methods,
applications, and products. However, I hope that you can identify and rely on only
those that are valid and useful. I hope this book helps you to do so and helps you to
develop your own feel for acidizing and its possibilities. Finally, I hope that you gain
an appreciation of the creative innovations in acid stimulation that BJ Services has
introduced and established in the industry and worldwide and that you will seek their
service and support.
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CONTENTS
List of Illustrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiii
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
PART I. PRELIMINARIES
1 A Brief History of Acidizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
The Beginning—Carbonate Acidizing. . . . . . . . . . . . . . . . . . . . . . . . . . .3
A New Beginning—Corrosion Inhibition . . . . . . . . . . . . . . . . . . . . . . .5
Sandstone Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
2 Acid Treatment Categories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Matrix Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Fracture Acidizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Acids Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
3 Formation Damage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Reservoir Geology and Mineralogy. . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Reservoir Fluids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Offset Well Production. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Production History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Fines migration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Inorganic scale deposition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Organic deposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Drilling History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Mud filtrate loss to the formation. . . . . . . . . . . . . . . . . . . . . . . . . . .32
Drill solids invasion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Whole mud loss to the formation. . . . . . . . . . . . . . . . . . . . . . . . . . .33
Cementing Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Completion and Perforation Reports. . . . . . . . . . . . . . . . . . . . . . . . . . .34
Workover History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Stimulation History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Acidizing Damage Mechanisms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Inadvertent injection of solids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Incompatible acids/improper mixing . . . . . . . . . . . . . . . . . . . . . . . .36
Reprecipitation of reaction products . . . . . . . . . . . . . . . . . . . . . . . .36
Loss of near-wellbore compressive strength . . . . . . . . . . . . . . . . . .39
Formation of emulsions and sludges. . . . . . . . . . . . . . . . . . . . . . . . .39
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VIII PRODUCTION ENHANCMENT WITH ACID STIMULATION
Water blocking and wettability alteration . . . . . . . . . . . . . . . . . . . .39
Unbroken gel plugging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Posttreatment fines migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Hydraulic Fracturing Damage Mechanisms . . . . . . . . . . . . . . . . . . . . .41
Fines migration and plugging in the proppant pack . . . . . . . . . . . .41
Incompatible fracture fluid additives . . . . . . . . . . . . . . . . . . . . . . . .42
Unbroken gel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
PART II. SANDSTONE ACIDIZING
4 Purposes of Sandstone Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Perforation Breakdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Near-Wellbore Formation Damage Removal. . . . . . . . . . . . . . . . . . . .49
5 Why Sandstone Acid Jobs Fail. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Treatment of High-Skin Wells with No Damage . . . . . . . . . . . . . . . . .57
Inadequate Formation Perforation. . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Use of Incorrect Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Use of Incorrect Volumes or Concentrations . . . . . . . . . . . . . . . . . . . .58
Use of Dirty Water to Mix Preflush or Overflush Stages . . . . . . . . . . .58
Failure to Clean Acid or Water Tanks . . . . . . . . . . . . . . . . . . . . . . . . . .58
Additive Overuse or Misuse. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Pumping the Acid Job above Fracturing Pressure. . . . . . . . . . . . . . . . .59
Inadequate Contact with the Damage . . . . . . . . . . . . . . . . . . . . . . . . . .59
Shutting in the Acid Treatment Too Long. . . . . . . . . . . . . . . . . . . . . . .60
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
6 Six Steps to Successful Sandstone Acidizing. . . . . . . . . . . . . . . . . . . . . . . . 63
Step One. Determine Whether Acid-Removable Skin Is Present . . . .66
Step Two. Determine Appropriate Fluids, Acid Types,
Concentrations, and Treatment Volumes. . . . . . . . . . . . . . . . . . . . . . .67
Tubing pickling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Crude oil displacement/organic deposit removal (optional) . . . . . .69
Formation-water displacement (optional) . . . . . . . . . . . . . . . . . . . .69
Acetic acid stage (optional). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
Acid preflush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
Main acid stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
Overflush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
Acid treatment volume and rate guidelines . . . . . . . . . . . . . . . . . . .74
Acid injection rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Acid treatment concentration guidelines . . . . . . . . . . . . . . . . . . . . .76
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CONTENTS IX
Step Three. Establish a Proper Treatment Additive Program. . . . . . . .80
Corrosion inhibitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82
Iron control agent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
Water-wetting surfactant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Mutual solvent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Alcohol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Nonemulsifier/demulsifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
Antisludging agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
Clay stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
Fines-stabilizing agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
Foaming agent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
Calcium carbonate/calcium sulfate scale inhibitor. . . . . . . . . . . . . .92
Friction reducer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92
Acetic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93
Step Four. Determine Treatment Placement Method. . . . . . . . . . . . . .94
Mechanical placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98
Chemical diversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
Step Five. Ensure Proper Treatment Execution and
Quality Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
Step Six. Evaluate the Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
Pressure monitoring during injection. . . . . . . . . . . . . . . . . . . . . . .110
Flowback-sample analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111
Production-rate comparison. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111
Poststimulation well testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Payout and cost ROI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
7 Unconventional Sandstone and Geothermal Well Acidizing Procedures . 117
Maximum-Rate/Maximum-Pressure HF Treatment. . . . . . . . . . . . . .117
CO-Enhanced HF Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120
2
High-Concentration HF Treatment . . . . . . . . . . . . . . . . . . . . . . . . . .121
Single-Step Sandstone Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
On-the-Fly Minimum-Volume HF Treatment . . . . . . . . . . . . . . . . . .123
Acidizing of Geothermal Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Candidate selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Acid treatment design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
Acid additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128
Acid placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128
Safety requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
8 Sandstone Acidizing in Horizontal Wells. . . . . . . . . . . . . . . . . . . . . . . . . . . 131
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134
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X PRODUCTION ENHANCMENT WITH ACID STIMULATION
PART III. CARBONATE ACIDIZING
9 Purposes of Carbonate Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Matrix Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
Fracture Acidizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
Practical Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139
Perforating fluid, perforation cleanup, and breakdown . . . . . . . . .139
Damage bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140
Formation stimulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140
10 Comments on the Chemistry and the Physics of Carbonate Acidizing. . . 143
Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144
Acids used in carbonate acidizing. . . . . . . . . . . . . . . . . . . . . . . . . .145
Reactions of acid with limestone and dolomite . . . . . . . . . . . . . . .146
Physics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150
Fracture acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150
Matrix acidizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .152
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155
11 Carbonate Matrix Acidizing: Systems and Procedures . . . . . . . . . . . . . . . 159
Conventional Matrix Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
Pickling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160
Preflush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160
Acid stage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160
Overflush. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161
Retarded Acid Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161
Surfactant-retarded acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Chemical retardation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Physical retardation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Acid-Use Guidelines for Carbonate Matrix Treatments. . . . . . . . . . .164
Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .167
12 Carbonate Fracture Acidizing: Systems and Procedures . . . . . . . . . . . . . 169
Deciding between Acid Fracturing and Propped Fracturing . . . . . . .170
Acid Fracturing Treatment Procedures . . . . . . . . . . . . . . . . . . . . . . . .173
Viscous fingering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173
Viscous acid fracturing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .174
Closed-Fracture Acidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177
Treatment Evaluation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179
13 Carbonate Acidizing in Horizontal Wells. . . . . . . . . . . . . . . . . . . . . . . . . . . 181
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185
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CONTENTS XI
PART IV. SPECIALIZED REMEDIAL TREATMENTS
14 Inorganic Scale Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
15 Organic Deposit Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198
PART V. QUALITY CONTROL PRACTICES
16 Acid Treatment Quality Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Quality Control during Rig-up of Equipment . . . . . . . . . . . . . . . . . .201
Quality Control before Pumping. . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
Quality Control during Pumping. . . . . . . . . . . . . . . . . . . . . . . . . . . . .205
Quality Control after Pumping/during Flowback. . . . . . . . . . . . . . . .206
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209
17 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215
Appendix
A: Conventional Sandstone Acidizing Procedures. . . . . . . . . . . . . . . . . . . . 217
B: Conventional Carbonate Matrix Acidizing Procedures . . . . . . . . . . . . . . 225
C: Conventional Carbonate Fracture Acidizing Procedures . . . . . . . . . . . . 231
Low-Temperature (<200°F) Treatments . . . . . . . . . . . . . . . . . . . . . . .231
High-Temperature (>200°F) Treatments. . . . . . . . . . . . . . . . . . . . . . .235
D: Surfactants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Cationic Surfactants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229
Anionic Surfactants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .220
Nonionic Surfactants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .220
Amphoteric Surfactants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .221
Fluorocarbon Surfactants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .221
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
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