Gaswell Testing. Theory, Practice & Regulation. David A. T. Donohue President, IHRDC, Arlington Exploration Company

Transcription

1 Gaswell Testing

2 Gaswell Testing Theory, Practice & Regulation David A. T. Donohue President, IHRDC, Arlington Exploration Company Turgay Ertekin Assistant Professor, The Pennsylvania State University with the assistance of HowardB. Bradley International Human Resources Development Corporation Boston

3 Copyright 1982 by International Human Resources Development Corporation. All rights reserved. No part of this book may be used or reproduced in any manner whatsoever without written permission of the publisher except in the case of brief quotations embodied in critical articles and reviews. For information address: IHRDC, Publishers, 137 Newbury Street, Boston, MA ISBN-13: e-isbn-13: : / Library of Congress Catalog Card Number:

4 Table of Contents

5 Acknowledgments viii Preface ix Introduction 1 1. Conventional & Isochronal Tests Derivation of Fundamental Flow Equation Conventional Test Isochronal Test Modified Isochronal Test Additional Testing Options Pseudopressure (Real Gas Potential) Treatment for Gas Flow The Radial Diffusivity Equation for Gas Flow Analytical Solution of the Diffusivity Equation Flow Regimes Skin Factor Turbulent Flow Factor Drawdown or Falloff Test Buildup Test Determination of S, S' and 0 from Buildup and Drawdown Tests Additional Testing Considerations Surface-Pressure Relationships Stabilization Time and Radius of Investigation Choice of Flow Rates and Duration of Flow Rates Well bore Storage Effects Production of Liquids Single-Point Test The Orifice Meter Testing Equipment Measurement, Sampling, and Safety in Testing Procedures & Regulations Interstate Oil Compact Commission Procedures State of Texas Regulations State of Oklahoma Regulations State of New Mexico Regulations State of Louisiana Regulations Province of Alberta Regulations 124 vi Gaswell Testing

6 5. Field Test & Interpretation 6. Exercises Nomenclature & Units Appendix A Derivation of the Continuity Equation Appendix B Analytical Solution of the Diffusivity Equation Appendix C Skin Due to Restricted Entry Appendix 0 Determination of Gas Supercompressibility Factor and Viscosity Appendix E Orifice Coefficients Appendix F Sample Data Reporting Forms Index Table of Contents vii

7 Acknowledgments The authors of this book wish to thank the following individuals for the active support and encouragement they provided during its several stages of completion: Howard B. Bradley of Mobil Exploration and Producing Services, Inc. in Dallas who reviewed the full manuscript including the tables, figures and equations, offered continued support and criticism, and whose personal interest in both video production and the book led to its satisfactory completion; Aziz S. Odeh and William Prachner of Mobil Oil Corporation, Dallas, for the valuable suggestions they offered during the planning and working stages of the book and video production; Bruce jankura of Mobil Oil Corporation, Lake Charles, Louisiana for advice during planning and for his willingness to appear in the video production; Grant johnson of Mobil Canada Ltd., Edmonton and R. G. justice of Mobil Oil Corporation, Denver for their advice and recommendations during writing; Derek F. Harvey of Mobil Oil Corporation, New York for his careful helmsmanship; and especially to Michael Hays and Gail Smith of IHRDC for editorial assistance, review, and final publication. viii Gaswell Testing

8 Preface This book accompanies a videotape program of the same name. The combined videotape and book, referred to as a module of instruction, was one of three prepared by IHRDC on a joint basis with Mobil Oil Corporation during The three modules, one each in geology, geophysics, and petroleum engineering, were produced to determine whether this medium of instruction would provide an effective way of teaching recent graduates and those individuals changing specialties, "what they need to know, when they need to know it." A great deal was learned during the pilot stages. Properly designed and properly used, video-assisted instruction was found to be effective, efficient, and convenient. With the confidence that this instructional medium provides one way for the international petroleum industry to train young graduates in exploration and production, IHRDC sought financial and advisory support from a limited number of companies to undertake the development of the Basic Technical Video Library for the f&p Specialist. To date the following companies have agreed to serve as Sponsors: Mobil, AGIP, ARAMCO, Cities Services, Dome Petroleum Ltd., Gulf, Phillips, Standard Oil of California/Chevron, and Texaco. Work on the Library began in July With an accelerated production schedule of 24 modules per year and the continued support of the Sponsors, the Library should be completed in about five years. Preface ix