During construction of Sakhalin-2 Phase 2 production facilities, rental units provided a wide range of flexible power systems, according to Aggreko PLC, provider of the units.
Aggreko says the units supplied power during construction, commissioning, tow, and offshore hookup of the LUN-A and the PA-B production platforms off the eastern coast of Russia.
The platforms are four-legged concrete gravity-base substructures (CGBS) with fully integrated decks and living quarters for more than 100 people.
Sakhalin Energy Investment Co. Ltd. (SEIC) is the operator for developing the Sakhalin-2 integrated oil and gas project. Partners in SEIC are Shell Sakhalin Holdings BV, 55%; Mitsui Sakhalin Holdings BV, 25%; and Diamond Gas Sakhalin BV, 20%.
Production from Phase 1 started in July 1999 from the PA-A gravity based Molikpaq platform (OGJ, Oct. 1, 2001, p. 58). Phase 1 produces oil from the Vityaz complex that consists of the Molikpaq production platform, a single anchor-leg mooring buoy, and the Okha floating storage and offloading unit.
LUN-A temporary power
During construction of the 22,000-ton Lunskoye (LUN-A) topsides in South Korea, Samsung Heavy Industries (SHI) contracted the temporary power rental project to Aggreko. The project called for supplying a 7 Mw, 6.6-kv turnkey power generation system including a fire and gas detection and suppression system, winterization packages, and operation and maintenance of the packages.
Aggreko says it delivered temporary power and safety packages for the final phases of the platform’s topsides construction and subsequent commissioning (Fig. 1). The company retained the power plant and fire and gas detection and suppression equipment for supplying security during the tow period and for the offshore power cable hookup that required reliable power supply.
The LUN-A platform is in the Lunskoye gas and condensate field 15 km off the northeastern coast of Sakhalin Island, in 48 m of water. The platform is a drilling and production facility with minimum processing facilities. All oil-condensate and gas separation including gas treatment will be at an onshore processing facility on Sakhalin Island. After the facility separates the gas and condensate, pipelines will transport the fluids more than 800 km to an oil export terminal and Russia’s first LNG plant at Prigorodnoye on the southern end of Sakhalin Island.
LUN-A has a designed capacity for producing 1.8 MMcfd of gas, 34,000 b/d of liquids and condensate, and 16,000 bo/d. The platform has 27 well slots.
SEIC installed the gravity base in 2005 and the topsides in June 2006. It expects production to start in November 2008.
PA-B temporary power
Aggreko says as with the LUN-A platform, the 28,000 ton PA-B drilling, processing, and production topsides for the Pilton-Astokhskoye field required a temporary 7 Mw, 6.6-kv turnkey power rental system for the latter stages of the platform’s topsides construction and commissioning in the SHI yard (Fig. 2) as well as for the tow, power hookup, and commissioning phases offshore.
SEIC installed the 103,000-ton concrete base in July 4, 2005, with topsides installed in July 2007. It completed the hookup and commissioning in November 2007. SEIC expects production to start by yearend 2008.
Pilton-Astokhskoye field will produce from an oil reservoir with associated gas.
The PA-B platform is in 32 m of water, 13 km from the northeastern coast of Sakhalin Island. PA-B has a capacity to produce 70,000 bo/d and 92 MMcfd of gas.
Testing, commissioning
As well as Aggreko supplying the highly flexible temporary power packages, SHI awarded a contract to Aggreko for the testing and commissioning of the PA-B platform’s own turbine generators.
Aggreko says this task required it to deliver a rental 30 Mw, 6.6-kv resistive reactive load-bank testing package to the SHI shipyard in Korea 3 months prior to the sail-away of the PA-B topsides.
It notes that the testing of the platform’s turbine generators proved that the power equipment was in good condition and fully operable and ensured that the onboard power plant would deliver the power as needed.
The company adds that LUN-A topsides did not need the testing package because the platform will rely on a submarine cable for power.
Emergency power
Due to an emergency at the onshore processing facility’s (OPF) power plant on Sakhalin Island, SEIC also contracted Aggreko to supply two 22.5 Mv-amp high-voltage transformers on a rental basis because during the commissioning of the OPF’s permanent power plant’s transformer system, a serious fault developed on both main turbine transformers.
The two transformers came from Aggreko’s facility in Dubai and SEIC shipped the two 40-ton transformers from Dubai to Sakhalin Island onboard an Elusion 76 air cargo plane in two trips.
Aggreko says the emergency power project took a few days with the transformers delivered on a rental basis within 10 days of the emergency call.
