A “slug catcher” in a gas pipeline is a section of pipe that has been purposely “oversized” to slow down the gas velocity and allow liquid water to drop out of the gas flow. This arrangement is usually placed after a collection header from a natural gas field, and is used to eliminate large “slugs” of water coming off of the field.
A client had a gas production field, which could produce ~ 500 MMSCFD of gas. When the production was increased to ~1500 MMSCFD of gas, water in the piping system would overwhelm existing water cyclone separators and “trip” the compressors off. A slug catcher had been installed upstream of the cyclones, but was operating unsatisfactorily. Working with our client, the existing slug catcher design was analyzed, and found to be only about 20% efficient in water removal. Through an iterative process, an optimal modification was developed which gave in excess of 90% removal efficiency – at substantial savings compared to design/fabrication/installation of a new slug catcher.