Weatherford Finishes GreenStream Ops for Saipem

Weatherford's remarkable Temporary Air Compression Station (TACS), installed in Sicily, Italy, for wet buckle contingency during pipe-lay of a 32 in.-diameter gas export pipeline, has successfully assisted Saipem by delivering compressed air as required for dewatering and drying operations on the same line. The 520 km trans-Mediterranean pipeline, known as the Libya Gas Transmission System (LGTS) or GreenStream, runs from Mellitah, Libya, to Gela, Sicily, in water depths exceeding 1,100 m. It was laid by Saipem's Castoro Sei vessel and pre-commissioned by Saipem with Weatherford's support.

Weatherford's TACS boasts the largest fleet of purpose-built air compression equipment in the world. The majority of the compressors (58) are built with the unique "combination" design, incorporating a rotary screw and reciprocating "booster" compressor in a single 20-ft skid frame. The fully stand-alone TACS includes 4 feed compressors, 16 air dryers capable of dew points in excess of -60°C, 8 high-pressure boosters, 18 coalescing and carbon bed oil removal filters, flowmeters, centralized remote monitoring system, fuel pumping and distribution system and all support facilities (electrical generation, lighting, etc.).

The TACS retains a staggering 53,000 horsepower and produces more than 1,800 nm3/min (63,600 scfm) of compressed air at pressures up to 250 barg (3,625 psig). It also incorporates the facility for high-pressure nitrogen generation with the addition of Weatherford's membrane units.

The station was mobilized directly to Sicily from Russia, where it was successfully used to provide similar services to Saipem on the Blue Stream development project in the Black Sea. The entire Weatherford-GreenStream project work scope has had a contract value of €26m and a duration of two years. Weatherford's Pipeline & Specialty Services eastern-hemisphere manager commented, "The Temporary Air Compression Station is a truly unique facility and demonstrates Weatherford's commitment in providing pipeline pre-commissioning solutions for the rising number of deepwater developments worldwide." He added, "Installation of the TACS from availability of the site to mechanical completeness took only 16 days, a remarkable achievement."