Gea has delivered two centrifuges for monoethylene glycol (Meg) purification at BP’s West Nile Delta offshore natural gas field in Egypt.
Düsseldorf/Germany — The centrifuge package was delivered to BP’s gas treatment plant near the port of Alexandria. Its two WSD 200 centrifugal separators run in parallel 24 hours a day to deliver excellent separation performance and reliable operation on a single skid measuring 12 x 7 x 6 m.
The German company started work on the project at the end of 2015 and supplied the centrifuges on schedule in around 65 weeks. The complete Meg regeneration project was handled by the Wellstream Processing group, which is part of the Process and Flow Technologies business unit within National Oilwell Varco (Nov). This is Gea’s fourth project with Nov, on this occasion working with the company’s office in Oslo, Norway. Centrifuge manufacturing and project management were done at the supplier’s facility in Oelde, Germany. Gea’s Dubai office assisted with front-line contact. The centrifuge skid was assembled in Hereford, UK, by KGD, a trusted partner of Gea.
A Strategic Project
The West Nile Delta is a strategic project that will eventually supply almost 1.3 billion cubic feet a day (bcf/d) of gas, equivalent to about 30 % of Egypt’s current production. All this gas will feed into the Egyptian grid.
The complete development consists of five gas fields in water depths up to 750 m. BP holds an 83 % stake, with the balance owned by German oil and gas company Dea AG. Production started in March 2017, with the remaining fields expected on stream in 2019.
As well as natural gas, wellhead pipelines typically transport hydrocarbon liquids (condensate), water, corrosive salts, and sand. Within the pipeline there is a constant threat of erosion, corrosion and scale formation. Subsea pipelines operating at temperatures close to freezing also risk plugging with hydrates. These ice-like substances form when natural gas — methane — combines with water at low temperatures.
Recovering and Purifying Meg
Meg is used to protect gas pipelines from corrosion and blockage. It has a long history as an antifreeze in engines. Spraying it into pipelines binds condensate, water, salt, and corrosion particles, and stops ice and hydrates forming.
On the West Nile Delta project, Meg purified by Gea’s equipment protects a 42-km-pipeline carrying gas ashore from nine wells in the Taurus and Libra fields. Once the gas reaches the processing plant the Meg is recovered and purified for re-use. The company's centrifuges are an integral part of the Nov pre-treatment system, where they remove precipitated low-solubility salts and fines from the rich Meg. Subsequent purification steps include reconcentration and salt reclamation.