Central North Sea & CATS Pipeline
Natural Gas from the Central North Sea is transported to the TGPP via the bp operated Central Area Transmission System (CATS) pipeline. The CATS pipeline has a capacity of 1,700 mmscfd and at 36” and 404 km long represents one of the largest offshore gas gathering systems in Europe.
The CATS gas pipeline serves a number of large oil & gas and gas/condensate fields within the Central North Sea with the larger fields serving as hosts for smaller satellite fields.
Gas from the CATS pipeline that arrives on Teesside is called “wet” gas as it still contains Natural Gas Liquids (NGLs) as well as some water. This wet gas is unsuitable for use by consumers and requires processing before it can meet the specifications required for entry to the National Transmission System (NTS) or for sales to local industrial consumers on Teesside. Initially, the wet gas undergoes a dehydration process to remove waterpresent in the gas. Once the water is removed, thegas is chilled and the NGLs are removed leavingpredominantly methane in the gas stream. This isthen metered and exported as “dry” or sales quality gas.
The NGLs undergo further treatment through fractionation where the NGLs are separated into three useful products; Propane, Butane and Condensate. The separate NGL products are then transferred by pipeline either to liquid storage or to other petrochemical businesses based on Teesside for use as feedstock.