Practical Engineering Management of Offshore Oil and Gas Platforms

Naeim Nouri Samie

• Publisher: Gulf Professional Publishing
• Year: 2016
• ISBN:
  9780128096048
• Topic: Business
• Subtopic: Natural Resource Extraction Industry
• Index: Business

Practical Engineering Management of Offshore Oil and Gas Platforms delivers the first must-have content to the multiple engineering managers and clients devoted to the design, equipment, and operations of offshore oil and gas platforms.

Concepts explaining how to interact with the various task forces, getting through bid proposals, and how to maintain project control are all covered in the necessary training reference. Relevant equipment and rule of thumb techniques to calculate critical features on the design of the platform are also covered, including tank capacities and motor power, along with how to consistently change water, oil, and gas production profiles over the course of a project.

The book helps offshore oil and gas operators and engineers gain practical understanding of the multiple disciplines involved in offshore oil and gas projects using experience-based approaches and lessons learned.

• Delivers the first ever must-have content to the multiple engineering managers and clients devoted to the design, equipment, and operations of offshore oil and gas platforms
• Contains rules of thumb techniques to calculate critical features on the design of the platform
• Includes practical checklists for project estimates and cost evaluation for effective project execution in budgeting and scheduling
• Helps offshore oil and gas operators and engineers gain practical understanding of the multiple disciplines involved in offshore oil and gas projects using experience-based approaches and lessons learned

Part 1

Engineering Design of Offshore Platforms

Outline

Chapter 1. Introduction to Offshore Platforms

Chapter 2. Disciplines Involved in Offshore Platform Design

Chapter 3. Systems and Equipment for Offshore Platform Design

Chapter 1

Introduction to Offshore Platforms

Abstract

A very brief history of offshore oil and gas platforms is given. Functions of different types of platforms present in an offshore oil and gas complex like production, living quarter, wellhead, satellite, intermediate support, and flare platform are discussed. General guidelines in establishing orientation of a complex to follow safety and operational requirements are explained. Some components of a fixed platform like jacket, topside, boat landing, sea deck, riser, helideck, telecommunication towers, bridges, etc. are shown. The importance of engineering in procurement, fabrication, and operation with impacts on cost, time, safety, ease of operation, and producing the intended output is explained. Application of fail-safe concept in valve design is discussed.

Keywords

Fail safe; Flare; Living quarter; Offshore platforms; Production; Satellite; Wellhead

Offshore platforms have been fabricated for a variety of purposes. Army support units, surveillance activities, navigational purposes, etc. are all kinds of offshore platform usage. The study by Dawson [1] provides several examples of usage other than oil and gas sector. Many studies [5–14] have introduced different types of offshore platforms with an emphasis on structural behavior and configuration.

This book concentrates only on offshore platforms that are fabricated for drilling, transferring crude oil and gas to the surface, production enhancing, preliminary processing and transferring to onshore facilities, or exporting. In addition it concentrates on fixed-type jacket platforms. The studies by Patel [6] and Wilson [7] have given sketches showing platform type versus water depth. Above ∼400 m depth the fixed jacket platform becomes uneconomical. In ultra-deep waters, using this concept is not feasible.

Other types of platforms like guyed towers, tension legs, semisubmersibles, floating structures, etc. are out of this book discussion. Several issues have to be pointed out:

• The structural behavior of fixed jacket platforms is different compared with others. This applies to all aspects like analysis, approval, construction, transportation, and installation. Discussions in chapter “Disciplines Involved in Offshore Platforms Design,” Section 2.10 are related to fixed jacket platforms.

• In deep waters, due to higher cost of the supporting structure, it is not economical to dedicate each platform to a specific task, like accommodating operators, production, processing, etc. For these platforms normally all functions are performed on the same unit.

• Process design, power generation/distribution, control systems, piping, and installed equipment more or less follow the same concepts as explained in this book.

• Document handling and procedures applicable to engineering office are also the same.

It is not intended that we give a complete history of developments in this field. For a better description please refer to listed references.

Platforms can be divided based on their material of construction (ie, steel, concrete) and/or structural behavior (ie, fixed, floating, gravity, tension leg, etc.). These divisions serve very well in a structural design book. This book intends to describe the equipment/systems, design process, and design team interactions. The emphasis is on the performance. Therefore platforms are divided based on their function (ie, production, living quarters, etc.).

1.1. Offshore Platforms History

This book does not intend to give a history of offshore platforms. It only lists the main achievements. Probably the first oil wells were drilled on spots where oil had surfaced. Under heavy rock pressures oil had gradually seeped out to surface. People had been using them for a long time. Probably early Zoroastrians in Iran built their temples of worship over these locations, which had nonextinguishable fires. The tar collected from these pots was used for sealing ships.

It is said the first wells were drilled in California over these seeping points. Gradually operators understood that in some locations wells nearer to shore produce more oil. At that time and much later seismological investigations had not been developed. Therefore oil explorers were guided by actual production rates. Perhaps the first offshore platform was driven in 1887 when H. L. Williams proposed the idea of building a wharf and erecting a drilling rig on top of it. This first offshore well extended about 90 m in the ocean.

Oil exploration pioneers progressing into the ocean encountered many problems. If the supports were wooden, living organisms attacked it, and if they were made of steel, sea water would corrode it. Heavy storms hit the platforms. It was very costly to fabricate very huge structures. Therefore, rational evaluation of environmental forces became necessary. Costs were high and some of the failures were catastrophic. It was necessary to develop environmental data acquisition/forecasting techniques. As offshore platforms moved away from the beach to deeper waters, gaining geotechnical data became more important.

Before starting development on a location and fixing drilling point, studies are needed to ensure hydrocarbon exists in this location. This necessity has led to seismological studies.

In 1947 the first steel offshore platform was installed and drilled far away from shoreline. Companies continuously progressed to deeper water. The first offshore platform was installed in 6-m water depth. About 30 years later, in 1978 jackets were installed up to a depth of 311 m [6]. Cognac Platform has been fabricated in 386-m (1265-ft) water depth [7]. Beyond such depth using conventional jacket-supported platforms may not be economical. Other offshore platform types such as guyed tower and tension leg platforms were developed.

Fixed jacket structures were fabricated in different designs like monopods, tripods, four-, six-, or eight-legged jackets, lifted jackets, launched jackets, gravity-based structures, etc. to suit design requirements.

In deep waters fixed jackets may not be economical. Instead, floating structures like semisubmersibles and drill ships have been used.

1.2. Oil and Gas Offshore Platform Types

Oil and gas may be found in large reservoirs either offshore or onshore. In some cases these reservoirs are located several thousand meters below the surface. Long wells must be drilled to access them. Offshore wells can be drilled from a fixed jacket, drillship, or template installed at the seabed. Based on oil and gas composition, reservoir pressure, and temperature, some processing needs be done to enable their safe/economical transfer to onshore or exporting facilities. Necessary equipment shall be installed on a platform. In add...