What is carryover in oil and gas?

What is carryover in oil and gas?

What Is Liquid Carryover?

  • Liquid carryover refers to the unintentional entrainment of liquid droplets in a gas or vapor stream. In the oil and gas industry, this phenomenon occurs during the separation process when liquid components (such as crude oil) are not completely separated from the gas phase.
  • When liquid carryover happens, small oil droplets exit with the gas stream, leading to various operational challenges and safety concerns.

Implications of Liquid Carryover:

Safety Concerns:

  • Liquid carryover can cause erosion, corrosion, and mechanical damage to downstream equipment.
  • For example, in gas compressors, excessive liquid carryover can lead to dry gas seal wear, containment loss, and potential explosions.

Financial Impact:

  • Unexpected wet gas affects fiscal measurements of flow and calorific value, impacting revenue.

Reduced Efficiency:

  • Liquid carryover interferes with efficient gas processing, affecting heat exchange and fluid dynamics.
  • It leads to decreased process efficiency and suboptimal product quality.

Environmental Impact:

  • Minimizing venting of natural gas is crucial due to methane’s high CO2 equivalent.
  • Liquid carryover contributes to environmental emissions.

Preventive Measures:

  • Proper design and maintenance of oil/gas separators are essential.
  • Regular inspection and cleaning of separators to prevent liquid carryover.
  • Monitoring liquid levels and implementing alarms for early detection.
  • Ensuring proper gas-liquid separation in scrubbers and filters.
  • Avoiding excessive flow rates that exceed design limits.

Separator Components:

An oil/gas separator typically consists of the following components:

  • Inlet device for preliminary phase separation.
  • Baffles downstream to improve flow distribution.
  • Separation enhancement device for major phase separation (gravity settling).
  • Mist extraction device to reduce liquid content in the gas stream.
  • Various weirs to control liquid levels.
  • Vortex breaker to prevent gas carryunder at the liquid phase outlet.
  • Pressure relief devices.

Separator Orientation:

  • Oil/gas separators can be either horizontal, vertical, or spherical based on vessel configurations.
  • They are the first vessels the well stream flows through after leaving the producing well.

Remember that addressing liquid carryover is crucial for safe and efficient oil and gas operations. Proper separator design and maintenance play a significant role in minimizing its impact.