Existing VRT Assessment and Standardization

Table of Contents

Type / Description

  • Market standard VRT designs, based only on 30-minute residence time criteria resulted in:
  • Larger vessels to cope with increased processing capacity requirements leading to higher total installation costs
  • Poor hydraulic and thermodynamic performance leading to frequent operational issues such as flooding, liquid carry-over into the gas stream, poor liquid degassing, and high RVP crude oil


  • Simplify the VRT model to reduce total installation costs
  • Address hydraulic and physical issues observed in market standard equipment
  • The vessel should consist of pipes instead of heads and shells
  • The new design should consistently achieve the stringent RVP specs

Project Development

  • The main physical phenomena involved in the degassing process of crude oil were figured out and analyzed
  • A vertical design was developed based on equipment familiar to operators and an optimized horizontal model was developed as well
  • A spreadsheet was provided with sizing calcs for two alternative vessel configurations
  • Mechanical drawings were provided for vessel fabrication


  • The new minimalistic VRT standard addressed the hydraulic and physical issues and reduced the total installation costs
  • The provided design maximized the liquid film area exposed to the lowest pressure to facilitate degassing
  • The enhanced gravity separation inlet favored the liquid degassing minimizing foaming

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