Customer’s problem

BP has been producing oil on the King field in the Gulf of Mexico since 2002. In order to increase recovery and extend the economic life of the field, the company embarked on a project to install two subsea multi-phase booster pumps. As part of this project, there was a requirement to provide communications for monitoring pump speed and lubricant oil pressure. In order to ensure high transmission speed, fibre optics were specified, and Expro was selected as one of the connector vendors.

Expro’s solution

The solution comprised a number of connectors and ancillary equipment from Expro’s FoeTRON product range, including an umbilical termination unit, optical fibre management units, and wet mate hybrid electro-optic connectors, some utilising both electrical and optical elements. All components were interconnected using oil filled pressure balanced hoses.

Results

The system was successfully deployed in October 2007.

These challenges came mainly as a result of a shore-based underwater trials programme devised to replicate the operational interface prior to subsea installation. The objective of the trials was to demonstrate that successful mating and demating of a wet mate plug/receptacle connector pair could be achieved for a specified number of mate/demate cycles against a defined operational interface provided by a ROV.

Consultation with the customer took place to review the impact on the impending deployment and to make proposals for risk mitigation. It was mutually agreed to proceed with deployment but with a revised approach to ROV actuation, thereby eliminating the potential for damage as experienced in the trials.

Technologies used

The FoeTRON connector range has, at its heart, a method which provides accurate and repeatable subsea mating and aligning of two single mode optical fibres, the core of which are only nine microns in diameter. Standard telecommunications style ceramic ferrules and aligning split sleeves are housed within oil filled housings, utilising Expro’s renowned CE (controlled environment) principle – this ensures all critical components are protected at all times from seawater ingress, and are pressure balanced to minimise stress and allow use in deepwater (the water depth on the King field ranges from 1600 to 1800m).

Due to the effects of pressure on optical joints, investment had to be made in high strength fusion splicing and recoating equipment, to ensure the optical performance was not affected during the life of the product. Test and measuring equipment was also required, with optical loss test sets being required for FAT, and OTDRs (Optical Time Domain Reflectometer) for site terminations.