In approximately 1983, Al Look* (at that time the President of the Dowell Division of the Dow Chemical Company) noted that each day, hundreds (possibly thousands) of small chemical plants are set up in the world’s oil/gas fields, and hundreds of thousands of pounds of chemicals are pumped into the Earth to enhance and maintain the flow of oil and gas. Frequently at the end of the treatment, these “mini-plants” [see Fig. P.1 in API (2008) for drawing of a hydraulic fracturing set up] are broken down and transported to a new site. The chemistry applied is the same as might happen in a refinery or a chemical plant, but here, most of the reactions take place out of sight and control of the process engineers. Thus, the design of the chemistry is of particular importance because usually it cannot be changed once it is pumped. This book will describe how these underground reactions work to keep the world’s hydrocarbon life lines flowing.
This document has been written to provide an improved understanding of the role of chemical reactions for enhancing and maintaining the production of oil and gas. There are several books that describe the thousands of production chemicals in use and include those by Fink (2003), Fink (2011), and Kelland (2009). These documents are useful references and have been cited frequently by the authors of this book. In addition, the reviews in Economides and Nolte (2000) have several excellent chapters (Constein et al. 2000; Hill and Schechter 2001) on some aspects of production chemistry and their applications in acid and hydraulic prop stimulation. This current book will also review many new aspects of the application of chemistry for enhancement oil and gas production that have reached the market since 2000 and will provide new mechanistic information.
* Al Look. 1983. Private communication.
This publication will provide an overview of the science and technology of the use of many production chemicals to a general technically trained audience, with emphasis placed on the basic chemical and physical principles by which the chemicals can enhance or maintain oil and gas production.
The introductory chapter describes the production environment, problems that require chemical intervention, and thus, the need for the thousands of different chemicals that are in use. This chapter also reviews the important chemical and physical principles that are common to most if not all of the enhancement treatments. This also places the technical aspects of production management in the perspective of the upstream oil and gas business. Subsequent chapters discuss aspects of the use and mechanisms of the complex chemistries that take place with the application of flow assurance chemicals, during stimulation (reactive chemistry and prop fracturing) and chemically improved oil recovery, including the use of chemical tracers. A separate chapter (Chapter 6) emphasizes the importance of health, safety, and environmental compliance in all aspects of oilfield treatments. Most of the chapters of the book end with a section where successful chemical enhancement or control methods have been used to solve specific production problems.
An outline for analysis is
Is there a problem that requires an intervention?
If there is a problem, how bad will it be?
Can the problem be managed through engineering, and/or chemical means?
Evaluate the results of an intervention or control strategy.
Each major section and most subsections will include reviews of current literature as well as summaries of the consensus understandings from the literature cited.
Chapter 1—Introduction
This section describes the reasons producing formations require intervention to enhance or maintain production, and the various types of chemical intervention in use. This chapter also reviews basic chemical and engineering processes that occur in production operations. It emphasizes the commonality of many of the chemical and engineering processes across the various production enhancement processes.
Chapter 2—Chemistry of Production Impairment
This chapter describes processes that impair the production of oil and gas such as formation damage and formation (and then mitigation) of emulsions in the production stream. It also updates techniques for mitigating and inhibiting deposition of inorganic and organic materials using references from earlier sources (Frenier and Ziauddin 2008; Frenier et al. 2010).
Chapter 3—Formation Stimulation With Reactive Chemicals
This chapter reviews the chemicals and mechanisms of reactive fluids (including acids) stimulation of oil and gas formations.
Chapter 4—Propped Fracturing Chemistry and Applications
This chapter discusses techniques and chemicals for formation stimulation using hydraulic fracturing using essentially nonreactive fluids.
Chapter 5—Improved Oil Recovery Chemical Applications
This chapter provides details of the chemicals and formation interactions that allow chemical sweep methods and conformance control processes to enhance hydrocarbon recovery. This chapter also gives a short review of the use of chemical tracers.
Chapter 6—Health, Ecology, and Safe Handling of Treating Chemicals and Produced Fluids
This chapter reviews general guidelines for planning and use of potentially toxic or hazardous chemicals that are frequently part of a treatment. Included is a discussion of the hazards associated with flowing back fluids. This chapter also reviews the use of chemicals to remediate spills of crude oil or production chemicals.
Chapters 1 through 5 each conclude with a “Things to Think About” section that summarizes the major findings revealed by the review of the technologies that were discussed and how this knowledge can be applied to chemical production management projects. Chapters 2 through 5 also have a section titled Histories and Best Practices (based on the technologies in that chapter). Here, the science and engineering principles described in the earlier sections are illustrated through practical demonstrations of chemical intervention and remediation.
Definition of the Upstream Oilfield Environment
The scope of this document is limited to chemical intervention and enhancement in the production (“upstream”) oilfield environment. This includes the entire production field including injection wells, the producing formation, and especially the near wellbore area as well as flowlines and gathering lines. This includes the natural or artificial tubulars, subsurface devices, gathering lines, and wellsite surface equipment. The book will not describe chemicals in use to drill, complete, or cement the well field. See the books by Growcock (2005) and Nelson and Guillot (2005). The discussion will also not include problems in transmission pipelines or refineries. However, many of the techniques and technologies needed are very similar to those described in this book and could be applied with appropriate modifications. See Frenier (2001b) for a review of cleaning of industrial equipment, including the downstream oil and gas equipment.
