ENVIRONMENTAL CONTROL 1Lt PnroLru/$~ rL\_'GLtLELL;l [((I: This Page Intentionally Left Blank ENVIRONMENTAL CONTROL JOHN C. RElS Gulf Publishing Company Houston, London, Paris, Zurich, Tokyo ENVIRONMENTAL CONTROL IN PETROLEUM ENGINEERING Copyright © 1996 by Gulf Publishing Company, Houston, Texas. All rights reserved. Printed in the United States of America.
This book, or parts thereof, may not be reproduced in any form without permission of the publisher. Gulf Publishing Company Book Division P. Box 2608 • Houston, Texas 77252-2608 10 9 8 7 6 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data Reis, John C. Environmental control in petroleum engineering / John C.
Includes bibliographical references and index. Petroleum engineering—Environmental aspects.6—dc20 95-48462 CIP Printed on Acid-Free Paper (oo) Contents Acknowledgments viii Preface ix CHAPTER 1 Introduction to Environmental Control in the Petroleum Industry 1 Overview of Environmental Issues, 2. CHAPTER 2 Drilling and Production Operations 18 Drilling, 18. CHAPTER 3 The Impact of Drilling and Production Operations 71 Measuring Toxicity, 71.
Effects of Offshore Platforms, 128. CHAPTER 4 Environmental Transport of Petroleum Wastes 139 Surface Paths, 139. CHAPTER 5 Planning for Environmental Protection 144 Environmental Audits, 145. Waste Management Plans, 149.
Waste Management Actions, 151. Certification of Disposal Processes, 162. CHAPTER 6 Waste Treatment Methods 172 Treatment of Water, 172. Treatment of Solids, 185.
Treatment of Air Emissions, 194. CHAPTER 7 Waste Disposal Methods 203 Surface Disposal, 203. CHAPTER 8 Remediation of Contaminated Sites 216 Site Assessment, 216. APPENDIX A Environmental Regulations 230 United States Federal Regulations, 231.
Regulations in Other Countries, 249. Cost of Environmental Compliance, 250. APPENDIX B Sensitive Habitats 256 Rain Forests, 256. Chemical Waste Exchanges 258 APPENDIX D Offshore Releases of Oil 261 Natural Dispersion of Oil, 261.
Enhanced Removal of Oil, 264. Index 271 Acknowledgments I would like to thank the many students who provided feedback on the course notes that eventually lead to this book. I would also like to thank Larry Henry for his thoughtful review of the manuscript. I gratefully acknowledge the donation of the reports by the American Petroleum Institute that are cited in this book.
Preface With the rise of the environmental protection movement, the petroleum industry has placed greater emphasis on minimizing the environmental impact of its operations. Improved environmental protection requires better education and training of industry personnel. There is a tremendous amount of valuable information available on the environmental impact of petroleum operations and on ways to minimize that impact; however, this information is scattered among thousands of books, reports, and papers, making it difficult for industry personnel to obtain specific information on controlling the environ- mental effects of particular operations. This book assembles a sub- stantial portion of this information into a single reference.
The book has been organized and written for a target audience having little or no training in the environmental issues facing the petroleum industry. The first chapter provides a brief overview of these issues. The second chapter focuses on the various aspects of drilling and production operations, while the third chapter discusses the specific impacts associated with them. Chapter 4 discusses ways in which toxic materials can be transported away from their release sites.
(Actual waste transport modeling is a very complex topic and is beyond the scope of this book.) The fifth chapter presents ways to plan and manage activities that minimize or eliminate potential environmental impacts without severely disrupting operations. The sixth chapter discusses the treatment of drilling and production wastes to reduce their toxicity and/or volume before ultimate disposal. Chapter 7 presents disposal methods for various petroleum industry wastes. The final chapter reviews available technologies for remediat- ing sites contaminated with petroleum wastes.
A summary of major United States federal regulations, a list of major U. chemical waste exchanges, and discussions of sensitive habitats and offshore releases of oil are provided in the appendixes. This book has evolved from course notes developed by the author for use in undergraduate and graduate classes. In preparing the book, the author has read thousands of pages of papers, reports, manuals.
and books on the topic of environmental concerns facing the upstream petroleum industry. Although it is believed that this book is technically accurate, some errors and omissions have invariably occurred. There are many excellent papers and studies that are not included because the author did not become aware of them prior to publication of the book. The author welcomes constructive comments that may improve future editions.
CHAPTER 1 Introduction to Environmental Control in the Petroleum Industry The upstream petroleum industry, which conducts all exploration and production activities, provides essential petroleum products that are used for transportation fuels, electrical power generation, space heating, medicine, and petrochemicals. These uses of petroleum are major contributors to our present standard of living. The activities of finding and producing petroleum, however, can impact the environ- ment, and the greatest impact arises from the release of wastes into the environment in concentrations that are not naturally found. These wastes include hydrocarbons, solids contaminated with hydrocarbons, water contaminated with a variety of dissolved and suspended solids, and a wide variety of chemicals.
While some of these wastes can have significant adverse effects on the environment, some have little impact, and others are actually beneficial. In virtually all cases, the adverse impact can be minimized or eliminated through the implementation of proper waste management. The most important steps in minimizing adverse environmental impact are for the industry to take a proactive approach to managing operations and become educated about those activities that can potentially harm the environment. The proactive approach involves adopting an attitude of environmental responsibility—not just to comply with regulations but to actually protect the environment while doing business.
2 Environmental Control in Petroleum Engineering 1.1 OVERVIEW OF ENVIRONMENTAL ISSUES Finding and producing oil and gas while minimizing adverse environ- mental impact requires an understanding of the complex issues facing the upstream petroleum industry. These issues concern operations that generate wastes, their potential influence on the environment, mech- anisms and pathways for waste migration, effective ways to manage wastes, treatment methods to reduce their volume and/or toxicity, disposal methods, remediation methods for contaminated sites, and all applicable regulations.1 Sources of Wastes Wastes are generated from a variety of activities associated with petroleum production. These wastes fall into the general categories of produced water, drilling wastes, and associated wastes. Produced water accounts for about 98% of the total waste stream in the United States, with drilling fluids and cuttings accounting for the remaining 2%.
Other associated wastes combined contribute a few tenths of a percent to the total waste volume (American Petroleum Institute, 1987). The total volume of produced water in the United States is roughly 21 billion barrels per year (Perry and Gigliello, 1990). A typical well can generate several barrels of fluid and cuttings per foot of hole drilled. In 1992, 115,903,000 feet of hole were drilled in the United States (American Petroleum Institute, 1993), yielding on the order of 300 million barrels of drilling waste.
Produced water virtually always contains impurities, and if present in sufficient concentrations, these impurities can adversely impact the environment. These impurities include dissolved solids (primarily salt and heavy metals), suspended and dissolved organic materials, forma- tion solids, hydrogen sulfide, and carbon dioxide, and have a defi- ciency of oxygen (Stephenson, 1992). Produced water may also contain low levels of naturally occurring radioactive materials, or NORM (Gray, 1993). In addition to naturally occurring impurities, chemical additives like coagulants, corrosion inhibitors, emulsion breakers, biocides, dispersants, paraffin control agents, and scale inhibitors are often added to alter the chemistry of produced water.
Water produced from waterflood projects may also contain acids, oxygen scavengers. Introduction to Environmental Control in the Petroleum Industry 3 surfactants, friction reducers, and scale dissolvers that were initially injected into the formation (Hudgins, 1992). Drilling wastes include formation cuttings and drilling fluids. Water- based drilling fluids may contain viscosity control agents (e., clays), density control agents, (e., barium sulfate, or barite), deflocculants, (e., chrome-lignosulfonate or lignite), caustic (sodium hydroxide), corrosion inhibitors, biocides, lubricants, lost circulation materials, and formation compatibility agents.
Oil-based drilling fluids also contain a base hydrocarbon and chemicals to maintain its water-in-oil emul- sion. The most commonly used base hydrocarbon is diesel, followed by less toxic mineral and synthetic oils. Drilling fluids typically contain heavy metals like barium, chromium, cadmium, mercury, and lead. These metals can enter the system from materials added to the fluid or from naturally occurring minerals in the formations being drilled through.
These metals, however, are not typically bioavailable. An extensive discussion of the environmental impacts of drilling wastes has been presented by Bleier et al. Associated wastes are those other than produced water and drilling wastes. Associated wastes include the sludges and solids that collect in surface equipment and tank bottoms, pit wastes, water softener wastes, scrubber wastes, stimulation wastes from fracturing and acidiz- ing, wastes from dehydration and sweetening of natural gas, transporta- tion wastes, and contaminated soil from accidental spills and releases.
Another waste stream associated with the petroleum industry is air emissions. These emissions arise primarily from the operation of internal combustion engines. These engines are used to power drill- ing rigs, pumps, compressors, and other oilfield equipment. Other emissions arise from the operations of boilers, steam generators, natural gas dehydrators, and separators.
Fugitive emissions from leaking valves and fittings can also release unacceptable quantities of volatile pollutants. One common, but incorrect, perception of the petroleum exploration and production industry is that it is responsible for large-scale hydro- carbon contamination of the sea. The total amount of hydrocarbons that enter the sea is estimated to be 3.2 million metric tons per year. The individual contributions from the different sources of hydrocarbons is given in Table 1-1 (National Research Council, 1985).
The primary source of hydrocarbon releases into the ocean is from transportation Environmental Control in Petroleum Engineering Table 1-1 Sources of Hydrocarbon Inputs into the Sea Amount Introduced Source (metric tons/year) Natural Sources 0.02) Bilge and fuel oils (0.3 Municipal and Industrial 1.1) Nonrefining industrial wastes (0.2 Source: from National Research Council, 1985. Copyright © 1985, National Academy of Sciences. Courtesy of National Academy Press, Washington, D. Oil production from offshore platforms contributes less than 2% of the total amount of oil entering the sea.2 Environmental Impact of Wastes The primary measure of the environmental impact of petroleum wastes is their toxicity to exposed organisms.
The toxicity of a sub- stance is most commonly reported as its concentration in water that results in the death of half of the exposed organisms within a given length of time. Exposure times for toxicity tests are typically 96 hours, Introduction to Environmental Control in the Petroleum Industry 5 although other times have been used. Common test organisms include mysid shrimp or sheepshead minnows for marine waters and fathead minnows or rainbow trout for fresh waters. The concentration that is lethal to half of the exposed population during the test is called LC^^.
High values of LC^^ mean that high concentrations of the substance are required for lethal effects to be observed, and this indicates a low toxicity. A related measure of toxicity is the concentration at which half of the exposed organisms exhibit sublethal effects; this concentration is called EC^^. Another measure of toxicity is the no observable effect concentration (NOEC), the concentration below which no effects are observed. The environmental impact of hydrocarbons in water varies consider- ably (National Research Council, 1985).
The toxicity of aromatic hydrocarbons is relatively high, while that of straight-chain paraffins is relatively low. LC^^ values for the most common aromatic hydro- carbons found in the petroleum industry (benzene, toluene, xylene, and ethylbenzene) are on the order of 10 ppm. Hydrocarbon concentrations of less than 1 mg/1 in water have been shown to have a sublethal impacts on some marine organisms. High molecular weight paraffins, on the other hand, are essentially nontoxic.