Handbook of Offshore Oil and Gas Operations

James G. Speight

• Publisher: Gulf Professional Publishing
• Year: 2014
• ISBN:
  9780080878195
• Topic: Tecnologia e ingegneria
• Subtopic: Combustibili fossili

Handbook of Offshore Oil and Gas Operations is an authoritative source providing extensive up-to-date coverage of the technology used in the exploration, drilling, production, and operations in an offshore setting. Offshore oil and gas activity is growing at an expansive rate and this must-have training guide covers the full spectrum including geology, types of platforms, exploration methods, production and enhanced recovery methods, pipelines, and envinronmental managment and impact, specifically worldwide advances in study, control, and prevention of the industry's impact on the marine environment and its living resources. In addition, this book provides a go-to glossary for quick reference. Handbook of Offshore Oil and Gas Operations empowers oil and gas engineers and managers to understand and capture on one of the fastest growing markets in the energy sector today.

• Quickly become familiar with the oil and gas offshore industry, including deepwater operations
• Understand the full spectrum of the business, including environmental impacts and future challenges
• Gain knowledge and exposure on critical standards and real-world case studies

Chapter 1

Occurrence and Formation of Crude Oil and Natural Gas

Abstract

Crude oil use and the associated technologies, in one form or another, is viable for (at least) the next 50 years until suitable alternative forms of energy are readily available and developed on a sufficient scale to (at first) complement crude oil use and then (eventually) to replace crude oil as the dominant source of liquid. This chapter focuses on the various types of nomenclature used by the oil and gas industry as well as the types of crude oil that exist and could be recovered from offshore locations in which the reservoirs are under large bodies of water (specifically oceans).

Keywords

offshore

formation

accumulation

composition

gas hydrates

opportunity crudes

high acid crudes

foamy oil

resources

reserves.

Outline

1.1 Introduction 1

1.2 Offshore Oil and Gas 3

1.3 Formation and Accumulation 9

1.3.1 Formation 9

1.3.2 Accumulation 10

1.3.3 Composition 14

1.4 Definition of Oil and Gas 16

1.4.1 Conventional Crude Oil 16

1.4.2 Natural Gas 17

1.4.3 Gas Condensate 19

1.4.4 Gas Hydrates 20

1.4.5 Opportunity Crudes 22

1.4.6 High Acid Crudes 23

1.4.7 Foamy Oil 24

1.4.8 Heavy Oil 25

1.4.9 Extra Heavy Oil 26

1.4.10 Tar Sand Bitumen 26

1.4.11 Resources and Reserves 28

References 39

1.1. Introduction

Crude oil is the most commonly used source of energy and liquid fuels to such an extent that the use of crude oil is projected to continue in the current amounts for several decades (Speight and Ozum, 2002; Parkash, 2003; Hsu and Robinson, 2006; Gary et al., 2007; Speight, 2011a, 2014b). Geologically, crude oil is scattered throughout the earth’s crust, which is divided into chronological strata that are based on the distinctive systems of organic debris (as well as fossils, minerals, and other characteristics) (Table 1.1). Carbonaceous materials natural products such as coal, crude oil, and natural gas (fossil fuels) occur in many of these geological strata—the actual origin of fossil fuels within these formations is a question that has been debated for a century or more and still remains open to conjecture and speculation (Fig. 1.1) (Gold, 2013; Speight, 2013d, 2014a).

Table 1.1

The Geologic Timescale

Era	Period	Epoch	Approximate duration (millions of years)	Approximate number of years ago (millions of years)
Cenozoic	Quaternary	Holocene	10,000 years ago to the present
		Pleistocene	2	0.01
	Tertiary	Pliocene	11	2
		Miocene	12	13
		Oligocene	11	25
		Eocene	22	36
		Paleocene	71	58
Mesozoic	Cretaceous		71	65
	Jurassic		54	136
	Triassic		35	190
Paleozoic	Permian		55	225
	Carboniferous		65	280
	Devonian		60	345
	Silurian		20	405
	Ordovician		75	425
	Cambrian		100	500
Precambrian			3,380	600

Figure 1.1 Relationship of crude oil to other fossil fuels.

However, in recent years, the quality of crude oil shipped to refineries has deteriorated insofar as there are larger quantities of heavy oil and tar sand bitumen (oil sand bitumen) in the crude mix (Speight, 2013a,b,c). This is reflected in a progressive decrease in API gravity (i.e., increase in density or an increase in specific gravity), which is usually accompanied by a rise in sulfur content (Speight, 2014a). Furthermore, the increasing need for crude oil products (such as liquid fuels) has resulted in an increasing need to develop and recover crude oil from other than the conventional land-based operations. Outside the United States, deposits are now being tapped in Siberia, Australia, India, and China, with additional accumulations being developed on a world-wide scale. In fact, the distribution of crude oil occurs in such diverse locations as polar regions, temperate regions, and tropical regions as well as in land-based sedimentary basins to offshore (under-sea) sedimentary basins.

Crude oil use and the associated technologies, in one form or another, is viable for (at least) the next 50 years until suitable alternative forms of energy are readily available and developed on a sufficient scale to (at first) complement crude oil use and then (eventually) to replace crude oil as the dominant source of liquid fuels (Giampietro and Mayumi, 2009; EREC, 2010; Langeveld et al., 2010; Nersesian, 2010; Seifried and Witzel, 2010; Speight, 2011b; Lee and Shah, 2013). Therefore, a thorough understanding of the benefits and limitations of crude oil recovery, especially from offshore locations, is necessary and will be introduced within the pages of this book. For this particular chapter, the focus is on the various types of nomenclature used by the oil and gas industry as well as the types of crude oil that exist and could be recovered from offshore locations in which the reservoirs are under large bodies of water (specifically oceans), which is the subject matter of this book.

1.2. Offshore oil and gas

The reservoir rocks (onshore and offshore) that yield crude oil and natural gas range in age from Precambrian to Recent geolo...