Reservoir engineering

Splitting and lumping schemes of the plus-fraction .................................................
Splitting schemes ......................................... Lumping schemes ........................................

1137
1138 1148

Problems ..................................................... References ..................................................

1155 1159

APPENDIX.................................................. 1165 INDEX ......................................................... 1177

Second Edition

Second Edition

Gulf Professional Publishing
Boston • London • Auckland • Johannesbourg • Melbourne • New Delhi

Gulf Professional Publishing is an imprint of Butterworth-Heinemann. Copyright © 2001 by Butterworth-Heinemann A member of the Reed Elseviergroup Previously copyrighted © 2000 by Gulf Publishing Company, Houston, Texas All rights reserved. No part of this publication may be reproduced, stored in a retrival system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Recognizing the importance of preserving what has beenwritten, Butterworth-Heinemann prints its books on acid-free paper whenever possible. Library of Congress Cataloging-in-Publication Data Ahmed, Tared H., 1946Reservoir engineering handbook / Tarek Ahmed. p.cm. Includes bibliographical references and index. ISBN 0-88415-770-9 (alk. paper) 1. Oil reservoir engineering. 2. Oil fields. 3. Gas reservoirs. I. Title. TN871 .A337 2000 622’.3382--dc21 99-005377British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. The publisher offers special discounts on bulk orders of this book. For information, please contact: Manager of Special Sales Butterworth-Heinemann 225 Wildwood Avenue Woburn, MA 01801–2041 Tel: 781-904-2500 Fax: 781-904-2620 For information on all Butterworth-Heinemannpublications available, contact our World Wide Web home page at: http://www.bh.com 10 9 8 7 6 5 4 3 2 1 Printed in the United States

To my gorgeous wife Shanna, And my beautiful children Jennifer Justin Brittany Carsen

ACKNOWLEDGMENTS ............................. PREFACE TO THE SECOND EDITION ..... PREFACE TO THE FIRST EDITION .......... 1 FUNDAMENTALS OF RESERVOIR FLUID BEHAVIOR......................................
Classification of reservoirs and reservoir fluids ............................................................
Pressure-temperature diagram .................... Oil reservoirs ................................................ Gas reservoirs ............................................. Undefined petroleum fractions .....................

xiii xiv xv 1
1
2 4 10 24Problems ..................................................... References ..................................................

27 28

2 RESERVOIR-FLUID PROPERTIES ........
Properties of natural gases ......................... Behavior of ideal gases ............................... Behavior of real gases ................................. Effect of nonhydrocarbon components of the Z-factor..................................................
Nonhydrocarbon adjustment methods ......... The Wichert-Aziz correction method ............

29
29 30 36 44
45 45

Correction for high-molecular weight gases ........................................................... Direct calculation of compressibility factors .......................................................... Compressibility of naturalgases ................. Gas formation volume factor ....................... Gas viscosity ...............................................

49 54 59 65 67

Methods of calculating the viscosity of natural gases ............................................... Properties of crude oil systems ...................
Crude oil gravity ........................................... Specific gravity of...