Handbook of Pollution Prevention and Cleaner Production Vol. 1: Best Practices in the Petroleum Industry

Nicholas P Cheremisinoff, Paul E. Rosenfeld

• Publisher: William Andrew
• Year: 2009
• eBook ISBN: 9780815520368
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

This new Handbook provides a series of reference guides to cleaner production methods, technologies, and practices for key industry sectors. Each volume covers, for each industry sector:* the manufacturing technologies* waste management* pollution* methods for estimating and reporting emissions* treatment and control technologies* worker and community health risk exposures* cost data for pollution management* cleaner production and prevention alternativesBest Practices in The Petroleum Industry provides an overview of refineries and gas plant operations and identifies the key Environmental Aspects, supported by case studies of major incidents that resulted in catastrophic releases of oil and refined products, and a critical assessment of the methodology and calculation procedures that the industry relies on in preparing emissions inventories.  The authors offer alternative approaches to providing more accurate emissions estimates, and guidelines on cleaner production and pollution prevention practices for improving overall environmental performance. - Overview of the key Environmental Aspects of gas plant operations and refineries - Case studies of major incidents that resulted in catastrophic releases of oil and refined products, including the Santa Barbara oil spill of 1969 and the EXXON Valdez incident - Provides guidelines on cleaner production and pollution prevention practices for improving overall environmental performance

Chapter 1

The petroleum industry

1.1 Introduction

The petroleum industry refines crude petroleum and processes natural gas into a multitude of products. It is also involved in the distribution and marketing of petroleum-derived products. The primary family of pollutants emitted from these activities is volatile organic compounds (VOCs) arising from leakage, venting, and the evaporation of raw materials and finished products. The air emissions comprise point, fugitive, and area sources. Other significant air emissions include sulfur oxides, hydrogen sulfide, particulate matter, and a wide range of toxic chemicals. The operations within a typical refinery also emit a variety of criteria pollutants and toxic chemicals from fuel combustion devices. Oil- and gas-field operations as well as gas processing plants are also significant sources of emissions.

Historically the industry sector has not acted responsibly towards environmental management. Later chapters document poor environmental management practices that have stemmed from both unintentional and intentional actions. These actions have placed the public at risk from both chronic and acute exposures to various toxic chemicals, including significant amounts of carcinogens like benzene.

A problem with the sector is the lack of a systematic and transparent approach to the quantification and reporting of air emissions. The majority of air emissions from refinery operations are fugitive in nature. The literature that the authors have reviewed support that, on the whole, the industry continues to rely on the application of published emission factors that are not statistically significant and calculation procedures that favor low estimations. The under-reporting of air emissions has a significant advantage to companies because pollution fees imposed by regulators can be minimized and regulatory enforcement held in check. The sector thus has no direct financial incentives to improve on the accuracy of its quantification, reporting, and control of emissions.

In a report to Congress (Waxman report, 1999) it has been noted that oil refineries “vastly under-report leaks from valves to federal and state regulators and that these unreported fugitive emissions from oil refineries add millions of pounds of harmful pollutants to the atmosphere each year, including over 80 million pounds of volatile organic chemicals (VOCs) and over 15 million pounds of toxic pollutants.”

Fugitive emissions are the emissions from equipment leaks, such as from valves, storage tanks, and various support equipment. Over 50% of all reported VOC and toxic air emissions from refineries are fugitive emissions according to the US Environmental Protection Agency (EPA). The Waxman report goes on to state that the “refineries fail to report large volumes of fugitive emissions. The average oil refinery reports … that 1.3% of the valves at its facilities have leaks. In fact, the average leak rate from valves in refineries is 5.0% – nearly four times higher than the average reported leak rate.” This under-reporting is alarming because it means that emissions reported under the Toxic Release Inventory (TRI) program in the USA are unreliable and cannot be used as a basis for assessing industry environmental performance and community risk.

As noted in the Preface, it is our intent to provide greater transparency to the identification and quantification of emissions and waste streams from refinery and gas processing operations. It is also the intent of this handbook to document best management practices, cleaner production technologies, and pollution prevention practices that can assist in improving environmental performance.

This first chapter provides an overview of the most widely used technologies employed by the industry. Many of the descriptions of refinery process operations are taken from the US OSHA standards and US EPA’s AP-42 for background purposes. An identification of many of the sources of pollution is given along with these descriptions.

1.2 Oil- and gas-field operations

1.2.1 Field characterizations

Schlumberger World Energy Atlas lists more than 40,000 oil and gas fields of varying sizes throughout the world. Approximately 94% of known oil is concentrated in fewer than 1500 giant and major fields (Ivanhoe and Leckie, 1993). The largest discovered conventional oil field is the Ghawar Field in Saudi Arabia. Approximately 65% of all Saudi oil produced between 1948 and 2000 came from the Ghawar Field. Cumulative production to the end of 2005 was about 60 billion barrels (http://en.wikipedia.org/wiki/Ghawar_Field#cite_note-5). Currently it is estimated to produce over 5 million barrels (800,000 m³) of oil a day, which is roughly equivalent to 6.25% of global production. Ghawar also produces approximately 2 billion cubic feet (57,000,000 m³) of natural gas per day.

There are also massive unconventional oil fields, such as Venezuela’s Orinoco tar sands and Canada’s Athabasca tar sands. These fields reportedly may contain even greater reserves than the Ghawar Field.

Oil and gas fields are characterized by the geological structure of the field, as well as by the quality and composition of the production streams. Depending on the set of conditions, different and sometimes unique recovery processes are employed. Discoveries of new oil and gas reserves generally require drilling of very deep wells. As a consequence, the wellhead equipment must be capable of handling high-temperature/high-pressure hydrocarbons with a high degree of reliability.

Oil and gas reserves are brought to the surface through piping that runs the entire depth of the well, and which is hung within a steel casing. Since the casing diameter is larger than that of the piping, there is a void space or “annulus” between the tubing and the casing.

In many oil reservoirs the naturally occurring pressure is sufficient to force the crude oil to the surface of the well. This production process is referred to as “primary recovery” and most generally does not require the use of a compressor. However, the duration of the primary recovery is limited because at a certain point in time the natural energy to lift the oil is no longer adequate. After this point, a compressor and choke valve combination is used to restore or increase the pressure in the field. This phase of the well’s life is known as gas depletion and is a form of secondary recovery.

In situations where the oil reservoir pressure is not sufficient to ensure the desired level of production, pumping systems may be employed. Enhanced recovery systems are installed to increase production and/or to avoid the decline of production over the years and to increase the recovery ratio.

1.2.2 Drilling rigs

Boreholes are made to recover oil and gas using a machine known as a drilling rig. They can be mobile equipment mounted on trucks, tracks or trailers, or more permanent land- or marine-based structures (such as oil platforms, commonly called “offshore oil rigs”). The term “rig” refers to the complex of equipment that is used to penetrate the surface of the Earth’s crust. Small, portable systems are generally used for mineral exploration and drilling water wells, and in environmental investigations.

Larger, more fixed installations are capable of drilling through thousands of meters of the Earth’s crust. Large “mud pumps” circulate drilling mud (slurry) through the drill bit and the casing, for cooling and removing the “cuttings” while a well is being drilled. Hoists in the rig can lift hundreds of tons of pipe. Other equipment can force acid or sand into reservoirs to facilitate extraction of the oil or mineral sample. Marine rigs may operate many hundreds of miles or kilometers offshore with infrequent crew rotation.

An example of an onshore rig is shown in Figure 1.1. The following list provides definitions of each of the equipment components shown in the diagram. The equipment associated with a rig depends on the type of rig, but typically includes at least some of the following items:

1. Mud tank – often called mud pits; provides a reserve store of drilling fluid until it is required down the wellbore.

2. Shale shakers – separate drill cuttings from the drilling fluid before it is pumped back down the wellbore.

3. Suction line (mud pump) – intake line for the mud pump to draw drilling fluid from the mud tanks.

4. Mud pump – reciprocal type of pump used to circulate drilling fluid through the system.

5. Motor or power source – a hydraulically powered device positioned just above the drill bit used to spin the bit independently from the rest of the drill string.

6. Vibrating hose – a flexible, high-pressure hose (similar to the kelly hose) that connects the mud pump to the standpipe. It is called the vibrating hose because it tends to vibrate and shake (sometimes violently) due to its close proximity to the mud pumps.

7. Draw-works – the mechanical section that contains the spool, whose main function is to reel in/out the drill line to raise/lower the traveling block.

8. Standpipe – a thick metal tubing, situated vertically along the derrick, that facilitates the flow of drilling fluid and has attached to it and supports one end of the kelly hose.

9. Kelly hose – a flexible, high-pressure hose that connects the standpipe to the kelly (or more specifically to the gooseneck on the swivel above the kelly) and allows free vertical movement of the kelly, while facilitating the flow of the drilling fluid through the system and down the drill string.

10. Goose-neck – thick metal elbows connected to the swivel and standpipe that supports the weight of and provides a downward angle for the kelly hose to hang from.

11. Traveling block – moving end of the block and tackle; together they give a significant mechanical advantage for lifting.

12. Drill line – thick, stranded metal cable threaded through the two blocks (traveling and crown) to raise and lower the drill sting.

13. Crown block – stationary end of the block and tackle.

14. Derrick – the support structure for the equipment used to lower and raise the drill string into and out of the wellbore.

15. Monkey board – the structure used to support the top end of the stands of drill pipe vertically situated in the derrick.

16. Stand (of drill pipe) – sections of two or three joints of drill pipe connected together and stood upright in the derrick. When pulling out of the hole, instead of laying down each joint of drill pipe, two or three joints are left connected together and stood in the derrick to save time.

17. Pipe rack (floor) – a part of the drill floor (#21) where the stands of drill pipe are stood upright, typically made of a metal frame structure with large wooden beams situated within it. The wood helps to protect the end of the drill pipe from damage.

18. Swivel (on newer rigs this may be replaced by a top drive).

19. Kelly drive – drive unit.

20. Rotary table – rotates, along with its constituent parts the kelly and kelly bushing, the drill string and the attached tools and bit.

21. Drill floor – the area on the rig where the tools are located to make the connections of the drill pipe, bottom hole assembly, tools and bit. It is considered the main area where work is performed.

22. Bell nipple – a section of large-diameter pipe fitted to the top of the blowout preventers that the flow line attaches to via a side outlet, to allow the drilling fluid to flow back to the mud tanks.

23. Blowout preventer (BOP) annular – annular (often referred to as the Hydril, which is one manufacturer) and pipe rams and blind rams (see #24).

24. Blowout preventers (BOPs) pipe ram and blind ram – devices installed at the wellhead to prevent fluids and gases from unintentionally escaping from the wellbore.

25. Drill string – an assembled collection of drill pipe, heavyweight drill pipe,...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• About the authors
• Preface
• Chapter 1. The petroleum industry
• Chapter 2. The Santa Maria oil sumps
• Chapter 3. The Santa Barbara oil spill of 1969
• Chapter 4. Exxon Valdez oil spill
• Chapter 5. Best practices for developing fugitive emissions inventories
• Chapter 6. Guidelines for cleaner production
• Appendix
• Index