A confidential client wanted to evaluate methanol-injection system equipment at a meter and pressure control facility to determine its ability to operate in the installed conditions and according to the operating strategy, the desired control scheme alignment, and its characteristic operational effectiveness. The energy producer also wanted an evaluation of line heater installations and piping modifications for storage withdrawal at an additional meter and regulation site for ways to increase the reliability of the gas withdrawal cycle.
Barr was retained to perform a two-phased engineering study. First, Barr performed a site assessment of the methanol injection system as installed to document the existing piping, equipment, and control system and to predict potential site construction and operational constraints. We also examined the system for its ability to operate by reviewing equipment documentation for chemical compatibility, modeling for system flow anomalies, and documenting historical operating conditions.
We then analyzed the two sites for the potential value of adding equipment or systems to remove, condition, or chemically alter the flow stream to reduce hydrate formation from entrained liquids at pipeline-pressure-reduction control valves. Barr worked through the multiple gas conditioning options including centrifugal and two-phase separation, Joules-Thompson effect thermal heaters, chemical injection at wellhead locations, gas dehydration by TEG or molecular-sieve/desiccant, and piping modification to reduce turbulent flow conditions within the gas stream. All options were evaluated on a scale for initial capital investment by the client.
In a final report, Barr detailed recommendations for improving the gas withdrawal system for safer and more reliable pipeline operation. We also offered a “further analysis recommendation” to aid in building a technically complete package for proposals to conditioning equipment vendors.