There are many physical and financial factors that determine the optimum power generation solution on an Offshore installation - space requirements, weight, reliability, and maintenance requirements to name a few. On top of these factors, environmental impacts must be considered, such as emissions of Nitrous Oxides (NOx) and Carbon Dioxide (CO2), and visible pollution like flaring.
Whereas in ‘conventional’ offshore oilfields, there is usually associated gas available to provide the fuel for power generation, Heavy Oilfields provide an additional challenge: they tend to be gas deficient, with insufficient associated gas over field life to fully fuel a power plant. This requires the import of fuel, such as diesel or Heavy Fuel Oil, as these are easily transportable and storable, but importing fuels, and especially premium refined liquid fuels, increases operational costs. Therefore it may be necessary to look at using the produced crude oil itself as the fuel for power generation, and this in itself requires careful consideration by the providers of the different potential power generation technologies.
Liquid fuels also produce more NOx when burned, and are more carbon intensive than most gas fuels, increasing CO2 emissions. Heavy oil facilities usually need more heat for production and processing purposes than lighter crude oils, requiring combustion of more fuel to provide the process heat required and increasing CO2 emissions still further.
This paper looks at the types of liquid fuels, especially crude oil, and alternative power generation technologies that can be considered, and the potential advantages and disadvantages of these technologies in an Offshore application. It also looks at ways of reducing combustion emissions such as NOx and using Cogeneration as a means of reducing CO2 emissions by maximising overall energy efficiency.