Devon – Leland Sour Gas Dehydration Facility
Gas Liquids Engineering Ltd. (GLE) completed an engineering review of a 60 MMSCF/d very sour (31% H2S) dehydration facility, that was built in 1999. The facility had been recently acquired by the client and they were experiencing numerous leaking valves. GLE observed the following about the facility:
- The facility was found to be designed with a strong adherence to safety
- Design pressures are consistently high with few spec breaks
- Inlet ESD valves are provided, as are proper control valves per industry standard
- The equipment and piping were all designed in accordance with generally accepted engineering practices and sufficient design margins are present to allow for the very sour (>30% H2S) production gas.
- The facility was generally strongly designed
GLE provided the following recommendations:
- Review the use of the DADS chemical injection system. Investigate using a condensate solvent in lieu of DADS to prevent elastomer attack.
- Operate and cycle all plant valves periodically to ensure operation. This may not help the situation if it is due to seal failure or elastomer attack with DADS. Replace seized valves as necessary with gate or globe valves.
- Mechanically clean, prime and paint exterior piping
- Investigate the need for heat loop piping within the regeneration gas piping to assist in sulphur melting.
- Monitor corrosion of salt bath heater outlet piping, and review salt bath heater coil design criteria and replace heater and coil for severe corrosion protection.
- Add heat tracing to select equipment around the facility
- Review synchronization of generators
- Insure inlet filters are properly installed in the inlet filter separator