Natural Gas Engineering and Safety Challenges

At the present time, the gas industry in the UK and many other countries is based on the direct supply of natural gas. However, government and energy agencies are already planning for the major changes in energy supply which will be necessary in the medium-term future.

Once natural gas is first extracted from corresponding well, this is followed by gas treatment plant (downstream process), then via transmission pipeline to distribution network systems, and to the consumers. Through this transmission gas delivery, the concept of pipeline design is established through its location, the type of fluid being carried and its operating pressure and temperature are also of prime importance within this process. Unusual examples of severe location are the trans-Alaska pipeline where long sections are laid above ground to protect the permafrost and the Middle East, where long pipelines are laid both above and below ground and can be subjected to large temperature changes that bring complex design concepts. The operating pressure will determine the grade and wall thickness of the material, and temperature will also affect the requirements for pipe coatings, insulation, expansion joints, anchor blocks, etc. Gas pipelines require special attention over and above the normal design requirements for liquids because of the vast quantity of stored energy in the pipeline steel due to the compressibility of gas. The design should therefore take account of the probable consequences of failure and the parameters that can be adjusted to minimise the possibility of failure in pipeline systems. This chapter therefore attempts to provide the wide guidelines related to issues with the design and integrity of the transmission and distribution pipelines together with safety aspects of the systems.

In the late 1920s, transportation of liquefied gases in bulk started. In the very beginning, it was transportation of propane and butane in fully pressurised tanks. When the steel quality became better and the knowledge about propane and butane was better, they started to carry those liquefied gases under temperature control.

Since natural gas almost always flows through circular pipes, it is thus important to understand how the gas behaves in the pipes. What are the flow parameters and the properties of the flowing fluids and what are the gas flow governing equations in distribution and transmission systems? For gas flow in pipes, the parameters such as velocity, pressure and density, which describe the behaviour and state of a fluid, are not constant. They vary from one point in the pipe to another and from one instant in time to another.

Throughout the years, the gas industry has witnessed numerous different measurement techniques and experimental investigations relating to natural gas engineering, consequently making it extremely difficult to keep up to speed with the evolving technology that is being implemented across the world. In the gas industry, the measurements of temperature, pressure, gas flow and gas quality are some of the key parameters that are considered. However, due to the copious amount of measurement techniques that are available, it is impractical to detail each of these in this chapter. For this reason, the rationale is to capture the key points from the vast array of measurement techniques being used across the gas industry and present them in a clear and concise manner. In this chapter, attempt has been made to provide the knowledge necessary to understand the operational principles of instruments that are available in the gas industry to monitor parameters such as temperature, pressure, gas flow and gas quality. Contained within each of these sections will be a brief overview of the parameter being measured, the various types of instruments that are available to use for each parameter, along with the specific options which exist. At the end of each related section, all the instruments that have been highlighted are then shown in tabulated format which includes a brief operations of feature of the instrument, the range, the accuracy, advantages and disadvantages and application of each of the devices. This will provide the reader with sufficient data on the various instruments that can be used to measure the parameter being discussed. The conclusions drawn from each of the sections will then be presented at the end of the chapter. References are also provided with regard to design features of each instrument for further consultation.

The design and applications of the burners using natural gas have extensively been covered previously by Nasr et al. (Industrial sprays and atomisation. Springer, 2001, [1]) and Pritchard et al. (Industrial gas utilization, Engineering Principles and Practices, Bowker. British Gas Corporation, 1977, [2]). In the following section, however, a brief overview of various burners together with theoretical considerations, where appropriate, will be provided. This can also complement the subsequent sections in this chapter in terms of utilisation of natural gas relating to heat recovery, furnaces and elsewhere in the previous chapters.

Compliance with new UK and EU gas safety legislation for chemical processing plants is today a major factor influencing its design and operation. The activities of exploration and production of natural gas are associated with gas transportation, distribution and storage. In industrial, commercial and domestic markets, there are innumerable combusting flows as gas is burned as an end product by customers. In all these activities, accurate assessment of what would happen in the event of an operational or accidental release of gas, particularly where gas dispersion, fire or explosion might be involved, is an essential part of ensuring safe operations.

No matter where the gas is supplied from and where its destination is, the entire process, within the context of the natural gas business, should be managed in a coherent manner. This chapter thus starts by giving an overview of natural gas and its place as a viable source of future energy as well as providing information on the business elements of it. Moreover, the related legal framework of gas contract intends to give a better insight and knowledge when it comes to contract negotiation. After all we have to sell the gas once it has been produced. The chapter continues to give information on project evaluation, investment appraisal, teamworking, economic efficiency, gas chain and pricing of the gas.

The subject of innovation was firstly realised by the economist Joseph Schumpeter (Schumpeter in The theory of economic development, Harvard university press, Boston, 1934, [1]) in the 1930s.