This paper is intended to address the subject of local electrical power generation for remote subsea production development. Allied to this the provision of the infrastructure required to provide basic utilities to the development, specifically controls, processing, pumping and injection. Currently, a remote development, (for the purposes, one which is in excess of 10 km from an existing facility) will require an umbilical for the transport of electrical power, data, hydraulic control fluid and chemicals for injection into the well and the export pipeline. Where water or gas re-injection is required, these will have to be piped to the piped to the development. The export pipelines will carry the primary well product, (oil, gas, condensate) plus quantities of water and solid by-products. These utilities can be provided on site by a surface facility, (platform, EPSO) or a combination of surface and subsea equipment. A remote, marginal development will present problems in terms of the cost of providing utilities, in relation to the value of produced fluids. A balance is sought between the cost of the surface, versus that of installed umbilicals and pipelines run from a distant, existing facility. By generating electrical power locally in sufficient quantities, and uitilising packaged, subsea processing and pumping equipment, it is proposed that greater profitability can be achieved from marginal developments.


It is feasible to power a remote subsea development, requiring separation and boosting of produced fluids, with a local power supply generated by a moored, wind turbine.

Table 1(all tables, figures and calculations are printed at the end of this paper) indicates a possible economic breakpoint for capitol equipment cost, at an offset of 15 km distance. That is to say, the cost of providing a high voltage power line, a control umbilical and water injection line will exceed the cost of providing a wind turbine on a flotation structure, with linking catenary umbilical.

Table 2 indicates likely power requirement for two production options, and the load shedding regime to enable continued production, at reduced levels of available power. Option 1 show a lower overall power requirement attributable to complete separation of produced liquid and gas, and could be supported by a 2 MW surface facility. Option 2 shows higher power requirement, commensurate with partial separation and multi-phase pupped export. This could be supported by a 5MW facility.

In general the rated power the turbine will be achieved at a wind speed higher than the mean value found in the North Sea and North Atlantic (see Figure 1- European Wind Atlas) and the mean power output will be equivalent to the facility part load (1 MW for option 1, and 2 MW for option 2) The wind regime at deepwater ocean location is reasonably consistent, and the facility will at most times be operating between low and full load, with only short and occasional periods at standby load. Periods of calm are experienced most frequently during midsummer, when product demand is low, and when planned field shutdown for maintenance is usually carried out.

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