Case Studies – Highlights | Consultancy Services

High CO2 Gas Dehydration – Troubleshooting & Upgrading

Description

Dehydration of gas stream with high CO2 concentration

  • Several non-identified issues hindered the process stabilization and resulted in:
    • Difficulties to achieve water content spec on treated gas
    • Crystals formed in downstream JT unit
    • High TEG consumption

Challenge

  • After operator and several service companies were unable to identify the underlying factors causing the process upsets, it became critical to provide a definitive solution
  • Multicausal problem required a holistic approach to identify a proper solution.
  • Technical and operational experience required to fully address the matter

Project Development

  • Field diagnostic identified the multiple variables with impact on the process performance including operational conditions such as high gas temperature & high pressure, high CO2 concentration, compressor’s lube-oil carryover to contacting tower, foaming, and equipment bottlenecks among others.
  • Team was able to present several short-term and long-term solutions to address the issues

Outcome

  • Roughly two weeks after the customer contacted us, the short-term solutions were implemented and reductions in TEG consumption and replenish frequency were achieved reducing operating costs
  • After plant turnaround, the long-term solution was implemented, and the expected results in terms of product quality were achieved

Field Troubleshooting and facilities Upgrading

Description

Unconventional Field Troubleshooting

  • Multiphasic gathering network produced high slugging regime at CPF inlet
  • Pressure reduction from 80 to 15 barg in downstream flash separator. This caused self-refrigeration effect resulting in cryogenic temperatures of the liquid hydrocarbons
  • The non-stabilized hydrocarbon liquids stored in the atmospheric tank produced a boil-off stream of the lighter fractions of high MW gases into the atmosphere. This incident resulted in unsafe truck loading operation due to vented HCs at ground level resulting in VOCs concentration above LEL and permitted air quality levels

Challenge

  • The operator required a quick turn-around to resume operation under safe conditions
  • Prevent integrity problems due to continuous exposure to cryo-temperatures in the flash separator and atmospheric tank
  • Stabilize liquid hydrocarbons before storage to
    • Minimize atmospheric emissions of high MW hydrocarbon gases
    • Guarantee safer operation of liquid hydrocarbons truck-loading station
  • Prevent hydrates and wax deposition

Project Development

  • On the fly field assessment to gather information
  • Process reconfiguration with minimum intervention to prevent cryo-temperatures in process equipment and volatile liquids boil-off in the storage tank
  • Rapid identification and validation of readily available equipment (choke valve + glycol bath line-heater) in the area to revamp the process

Outcome

  • Through simple field analysis, our team was able to rapidly reconfigure the process using readily available equipment and granting safer operations while minimizing emissions of VOCs to the atmosphere