Unconventional Hydrocarbon Resources E-Book

Reza Barati

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: AGU Advanced Textbooks
• Sprache: Englisch

Seitenzahl: 1079

Veröffentlichungsjahr: 2020

Beschreibung

A comprehensive textbook presenting techniques for the analysis and characterization of shale plays

Significant reserves of hydrocarbons cannot be extracted using conventional methods. Improvements in techniques such as horizontal drilling and hydraulic fracturing have increased access to unconventional hydrocarbon resources, ushering in the “shale boom” and disrupting the energy sector.

Unconventional Hydrocarbon Resources: Techniques for Reservoir Engineering Analysis covers the geochemistry, petrophysics, geomechanics, and economics of unconventional shale oil plays. The text uses a step-by-step approach to demonstrate industry-standard workflows for calculating resource volume and optimizing the extraction process.

Volume highlights include:

• Methods for rock and fluid characterization of unconventional shale plays
• A workflow for analyzing wells with stimulated reservoir volume regions
• An unconventional approach to understanding of fluid flow through porous media
• A comprehensive summary of discoveries of massive shale resources worldwide
• Data from Eagle Ford, Woodford, Wolfcamp, and The Bakken shale plays
• Examples, homework assignments, projects, and access to supplementary online resources
• Hands-on teaching materials for use in petroleum engineering software applications

The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.

Leseprobe

Advanced Textbook Series

Unconventional Hydrocarbon Resources

Techniques for Reservoir Engineering Analysis

Editors

Reza Barati Ghahfarokhi

Mustafa M. Alhubail

This Work is a co‐publication of the American Geophysical Union and John Wiley and Sons, Inc.

This Work is a co-publication between the American Geophysical Union and John Wiley & Sons, Inc.

This edition first published 2021 by John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA and the American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C. 20009

© 2021 American Geophysical Union

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Library of Congress Cataloging‐in‐Publication data

Names: Barati Ghahfarokhi, Reza, author. | Alhubail, Mustafa M., author.Title: Unconventional hydrocarbon resources : techniques for reservoir engineering analysis / Reza Barati Ghahfarokhi, Mustafa M. Alhubail.Description: Hoboken, NJ : Wiley-American Geophysical Union, [2020] | Includes bibliographical references and index.Identifiers: LCCN 2020029620 (print) | LCCN 2020029621 (ebook) | ISBN 9781119420323 (paperback) | ISBN 9781119420491 (adobe pdf) | ISBN 9781119420675 (epub)Subjects: LCSH: Oil shale reserves--Textbooks. | Shale gas reservoirs–Textbooks. | Oil reservoir engineering–Textbooks. | Hydrocarbon reservoirs–Textbooks. | Hydraulic fracturing–Textbooks. | Petroleum–Geology–Textbooks.Classification: LCC TN858 .B37 2020 (print) | LCC TN858 (ebook) | DDC 553.2/83–dc23LC record available at https://lccn.loc.gov/2020029620LC ebook record available at https://lccn.loc.gov/2020029621

Cover Design: WileyCover Images: © Maximov Denis/Shutterstock

Contributors

Hajar Aghababa

PetroEconomic SolutionsLLC, Lawrence, Kansas, USA

Mustafa M. Alhubail

The University of Kansas, Lawrence, Kansas, USA

Reza Barati Ghahfarokhi

The University of Kansas, Lawrence, Kansas, USA

Sherifa E. Cudjoe

The University of Kansas, Lawrence, Kansas, USA

Qinwen Fu

The University of Kansas, Lawrence, Kansas, USA

Mohammad Kazemi

Slippery Rock University of Pennsylvania, Slippery Rock, Pennsylvania, USA

Xiaoli Li

The University of Kansas, Lawrence, Kansas, USA

Anil Misra

The University of Kansas, Lawrence, Kansas, USA

Negar Nazari

Stanford University, Stanford, California, USA

Edward Peltier

The University of Kansas, Lawrence, Kansas, USA

Stephen Randtke

The University of Kansas, Lawrence, Kansas, USA

Mojdeh Rasoulzadeh

The University of Alabama, Tuscaloosa, Alabama, USA

Ali Takbiri‐Borujeni

West Virginia University. Morgantown, West Virginia, USA

Jyun‐Syung Tsau

The University of Kansas, Lawrence, Kansas, USA

Preface

The development of ultra-tight hydrocarbon unconventional resources, which started in the early 21st century and has disturbed the energy sector, is an expensive and risky business. However, if the unconventional resources are properly developed, the business becomes quite lucrative. Consequently, the shale boom, which primarily occurred in the United States, has become a phenomenon that is spreading all over the world. Advanced technology (i.e., horizontal drilling and multistage hydraulic fracturing) has assisted in the development of unconventional resources; however, advanced technology must be supported with technical understanding of the fundamentals by the industry to commercially develop the unconventional resources.

This book offers a comprehensive guide to the methods and available techniques that are utilized in the industry to commercially develop unconventional resources with practical examples and projects using real‐world data sets of major unconventional plays such as the Bakken and Eagle‐Ford.

This book aims to cover the entire scope of hydrocarbon unconventional resources from discovery to commercial development based on the current understanding of the industry. Chapter 1 is an overview of unconventional resources and their importance, and it highlights the differences between the conventional reservoirs and the unconventional reservoirs. It also points out the top unconventional plays in North America and around the world stating the geological age, the estimated recoverable resources, and a summary of the petrophysical properties of each unconventional play in addition to the average cost of drilling and completing the wells with multistage hydraulic fracturing.

Chapter 2 discusses the petrophysical properties of unconventional reservoirs and the methods that are utilized in the industry to evaluate the rock properties, such as lithology, porosity and pore‐size distribution, permeability, relative permeability and capillary pressure, as well as water saturation and wettability. This chapter provides detailed explanation with examples of the techniques that assist in characterizing the unconventional reservoirs.

Chapter 3 presents the fundamentals of geochemical properties of unconventional reservoirs. The evolution steps of organic matter and the classifications of kerogen are also discussed. The methods to determine the source rock potential, such as the rock‐eval pyrolysis method, are explained in detail with examples. The thermal maturity and source rock assessment techniques are also explained in this chapter. Furthermore, Raman spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) are presented as valuable methods to analyze the thermal maturity of kerogen.

Chapter 4 deals with advanced imaging techniques and their applications to characterize organic‐rich shales. The different imaging and visualizing methods as well as the processing procedures are explained in detail with real‐world examples from different unconventional reservoirs, such as the Eagle‐Ford play.

Chapter 5 presents concepts and definitions of rock mechanics such as stress, strain, Young's modulus, and Poisson's ratio. The geomechanical properties of unconventional reservoirs, such as the minimum principal stress and its importance, closure stress, brittleness index, and the mineral‐based brittleness index, are explained in detail with examples. The methods to interpret well logs to obtain the geomechanical properties of unconventional reservoirs and to locate the optimum sweet spots for hydraulic fracturing are also discussed in this chapter.

Chapter 6 presents the fundamentals of hydraulic fracturing treatments, such as fracture geometry, fracture conductivity, multistage hydraulic fracturing, complex fracture networks, stimulated reservoir volume (SRV), and the fracture clean‐up process with case studies from some well‐known unconventional plays in North America. The microseismic and minifrac tests are also described. The purpose of the fracturing fluids, the different types of fracturing fluids, and their properties as well as the fracturing fluid design and selection process are discussed in detail. The purpose of proppant, the essential properties of the proppant, the different types of proppant, and the proppant selection process are also discussed in detail with examples. The modeling process of hydraulic fractures and the governing equations are described here.

Chapter 7 deals with the phase behavior of shale oil and gas. The compositional analysis of hydrocarbon unconventional fluids is explained in detail with PVT experiments. The equations of state (EOS) are also discussed with phase diagram examples. The laboratory experiments used to develop analytical and numerical methods required for EOS regression in addition to the minimum miscibility pressure estimation are explained with examples from different unconventional reservoirs, such as the Bakken, Eagle‐Ford, and Wolfcamp plays.

Chapter 8 discusses fluid flow through nanosized pores. The pore‐size distribution and its effects on fluid flow is explained. The complex flow regimes and the modeling techniques of fluid flow in nanopores are discussed in detail. The lattice Boltzmann model (LBM) as well as the molecular dynamic simulation methods and how they are implemented to conduct simulation in organic nanopores are also explained with examples.

Chapter 9 presents the history and purpose of the decline curve analysis (DCA) and rate transient analysis (RTA). The fundamental concepts of the DCA, such as the decline rate and the estimated ultimate recovery (EUR), are explained in detail with examples. The types of decline curves, such as the conventional Arps's models, as well as the modern decline curves, such as the modified hyperbolic model, the stretched exponential model, Doung’s model, and the multisegment model, are discussed. In addition, methods to determine the models' parameters are explained in detail with examples. The concept of RTA and the type curve methods are also discussed with examples and a chapter project.

Chapter 10 discusses the effects of unconventional resources on economics and energy security. The fundamentals of petroleum economics, such as business expenditure systems, net present value (NVP), and rate of return, are explained in detail with examples. The fiscal regimes, types of contracts, decision‐making processes, and risk analysis are also discussed with examples and a chapter project.

In Chapter 11, the environmental aspects of developing the hydrocarbon unconventional resources are explained. The concerns of water management, water reuse, and the impact on drinking water resources and air pollution are discussed. The types of chemicals that are used in the fracturing fluids, and the effects of induced seismicity are also covered in this chapter.

This book is intended to serve as a textbook for undergraduate and graduate students in petroleum engineering, geology, petrophysics, and for other readers interested in hydrocarbon shale resources. It is also intended to be a handbook for petroleum engineers, geologists, petrophysicists, petroleum economists, and employees with different backgrounds working in the oil and gas industry.

We would like to acknowledge different people and corporates who have helped in the preparation of this book. In particular, we thank all the contributing authors for their involvement in this book and for sharing their experience and knowledge. We would like to thank our publishing editor, Dr. Rituparna Bose, for her immense support. Our special thanks is extended to Slawson Exploration for donation of the Bakken data set, Kansas Geological Survey (KGS) for its open access database and for sharing valuable measurements on the Chattanooga shale, Chesapeake Energy for providing us with core and fluid samples and giving permission for publication to parts of the data.

Specifically, we would like to thank David Mohrbacher of Chesapeake Energy, Dr. Younes Jalali, Dr. Behruz Shakershiran from Uni Research CIPR, and Dr. Belladona Maulianda Hidayat from Universiti Teknologi Petronas for kindly reviewing chapters of this project and giving us feedback that improved the content. We also want to thank Schlumberger, IHS Markit, and NSI Technologies for providing us with data sets and core samples as well as licenses for advanced software packages.

Reza Barati Ghahfarokhi

Mustafa M. Alhubail

Lawrence, Kansas, USA

May 2019

1Introduction to Unconventional Hydrocarbon Resources

Mustafa M. Alhubail and Reza Barati Ghahfarokhi

The University of Kansas, Lawrence, Kansas, USA

1.1 Background

To better define the term unconventional resources, and to understand why they have been called unconventional, the history of oil should be reviewed.

Petroleum seeps are one of the earliest sources of oil, along with wood and coal, used for heating and illumination. Another source of oil for illumination was whales. Whaling, which is the term that describes hunting of whales, became a competitive industry in the eighteenth century. Factories were built to make ships, and well‐equipped fleets were sent for one purpose and one purpose only: hunting whales. Whale oil was mainly used in oil lamps (Jackson, 1998). The amount of oil from the above two sources was not sufficient enough for the high demand. With the industrial revolution, the need for an alternative source of energy, other than wood and coal, to maintain machinery and for transportation, had never been greater. Coal mining was a very dangerous occupation, and it resulted in a high number of casualties (Natgas, 2013). Hence, in the nineteenth century, oil exploration began, and it has changed the way the world operates in all aspects of life.

People started to dig wells using basic percussion tools, and the rubble was carried out by loading it into baskets and pulling it up to the surface. The drilling process improved a bit by using the cable‐tool drilling method, which helped drill wells faster. In the early twentieth century, rotary drilling was employed with the ability of cleaning the wellbore while drilling by using fluids. Rotary drilling has changed the whole petroleum industry and, over time, rotary drilling technology has been improved drastically (Hogg, 2016). With the ability to drill wells more conveniently using rotary drilling technology, there still exists a more challenging mission, which is where to drill. To this day, with the advancement in imaging the Earth's strata by using seismic waves, there is still uncertainty about whether hydrocarbon exists in a new area or not, and drilling is the only way to find out for sure.

The global demand for oil surged, and thousands of wells were drilled both onshore and offshore. Keep in mind that this whole process is an investment, and profit is the main motivation. To recover oil faster and without the need of drilling new wells from the start, horizontal drilling and directional drilling were employed. In addition to that, horizontal drilling also helped decrease the drilling footprint, which greatly helped minimizing the environmental impact from the drilling process. With directional drilling technique and the secondary and enhanced oil recovery methods (conventional methods), more hydrocarbons became accessible. However, even with directional drilling and the well‐established recovery methods, there is way more hydrocarbons that are trapped in certain reservoirs, and those hydrocarbons cannot be recovered by the conventional methods because of complex petrophysical properties of the reservoirs. Hence, the question now is how to extract the hydrocarbons that are trapped in those reservoirs. Those reservoirs are called unconventional reservoirs, and the hydrocarbons that are trapped in them are called unconventional resources. Thus, in general, the unconventional reservoirs can be defined as the reservoirs that contain a huge quantity of hydrocarbons that cannot be extracted by the conventional methods due to their petrophysical properties, which will be discussed in detail in Chapter 2. The unconventional resources are classified into different categories, and they will be discussed later in this chapter.

1.2 Overview of Shale Revolution

The shale boom primarily occurred in the United States. The unconventional resources have changed the energy sector and, in 2012, the number of wells that were brought back online in the United States alone exceeded those that were put online in the rest of the world excluding Canada (Maugeri, 2013). Figure 1.1 shows the number of the issued drilling permits just for the Eagle Ford play. Furthermore, other countries (e.g., Argentina and Colombia) are currently working on attracting talented workers, petroleum engineering experts, and foreign investments in order to replicate the U.S. shale boom to become independent on energy imports from other countries, and to become energy exporters as well (Kuuskraa et al., 2013). Therefore, it is fair to say that the shale boom is a U.S. phenomenon that is spreading all over the world. However, that is easier said than done.

Figure 1.1 Drilling permits issued for Eagle Ford play, 2008 through November 2018 (Railroad Commission of Texas).