source: finchannel.com | 24 June 2015
The FINANCIAL — Saudi Aramco has achieved a landmark by energizing its largest Tie-in Platform with a 230 kilovolt 46 km submarine composite cable, the longest of its kind.
The Tie-in Platform, named ‘TP-20’ lies in the world’s largest offshore field, Safaniya, and energizing it was the first phase of long-term plans to upgrade the Safaniya offshore field, referred to as the Safaniya Master Plan.
TP-20 will be the main crude oil gathering and power supply hub for North Safaniya offshore field. It is designed to provide 152 megawatts (MW) of electric power via a 46 km, 3-core 230 kV submarine composite cable (power and fiber) from a Saudi Electricity Company, newly-built 380/230 kV onshore substation, according to Saudi Aramco.
This 46 km, 3-core 230 kV submarine composite cable is the longest of its kind in the world and was installed as a single piece without a field splice. Considering the value of equipment at stake, the laying of the submarine cable was an extremely critical and complex operation.
The entire length of the submarine cable was transported from the manufacturer on a single vessel, known as a deep water cable laying vessel. Then, with the help of a shallow water cable laying barge, the cable was installed from onshore to offshore TP-20.
With the complete 230 kV electrical substation, the weight of TP-20 exceeds 6,000 metric tons. This staggering load cannot be handled by an industry standard marine crane. Therefore, the installation of TP-20 was performed using a unique float-over method.
Careful measures and plans were developed to ensure successful construction and installation of the platform.
Subsequent to the energization of TP-20, TP-18 and the nine wellhead platforms in central Safaniya field were also successfully energized under the same project. TP-18 is designed to provide 62 MW of electric power being fed via a 44 km, 3-core 115 kV submarine composite cable from a newly -built 230/115 kV onshore substation.
A complete electrical power system is delivering power to Safaniya’s remote offshore loads and has increased crude oil production more than 70 MBOD from the central Safaniya field – all this after a complex and challenging commissioning operation.