Perform a debottlenecking study of an aging Gas Dehydration Unit (GDU) treating natural gas from a declining gas field.
Process Engineering International, LLC (PROCESS) was contracted by a columns internals manufacturing company in the Middle East to perform a debottlenecking study of an aging Gas Dehydration Unit (GDU) that was designed to remove moisture from well-head gas streams. Over time, the gas field that feeds the existing GDU system had deteriorated so that the inlet pressures to the GDU were lower than the original design for the system and the compositions of the incoming gas had changed significantly. This resulted in reduced throughput and the need for a new or modified unit to continue operation for the coming years.
The owner/operator of the GDU was contemplating purchasing a new skid mounted unit or revamping the existing unit. PROCESS evaluated the existing system at both current and projected future conditions and determined that revamping the current system would be more economically favorable than purchasing a new unit.
To properly evaluate the revamp of the GDU, PROCESS prepared a simulation model of the GDU using commercial process simulation software. The following operations were a part of the debottlenecking study:
- Glycol Contactor
- Cross Exchangers and Coolers on Inlet and Outlet Streams of the Contactor
- Glycol Pumps
- Skimmer Tank
- Glycol Storage Tank Glycol Recovery Inlet/Outlet Heat Exchangers
- Glycol Recovery System
- Still Column
- Reflux Column.
Both the material & energy balance and system hydraulics were evaluated at current and projected future gas field conditions. Two options for upgrading were evaluated: Low Cost/Low Risk upgrades and Medium Cost/Minimal Risk Upgrades. Recommendations consisted of items such as:
- Specific revamp/upgrade recommendations for the existing equipment
- Addition of a new trim cooler
- Adding a bypass to select exchangers to improve pressure drop
- Removal of some pressure control devices
- Upgrading the meter station flow meter
- Replacing instrumentation as needed for new inlet pressure service
- Updating all process engineering data to reflect an upgraded system
- Performing annual checks and validating the simulation model material & energy balance information, along with the system hydraulics using up-to-date operating data as the field continues to deteriorate.
Oil & Gas Production
- Unit debottlenecking
- Process simulation and hydraulic modeling.