CGL® Marine Gas Monetization System



The CGL® System is provided as a “package Gas to Gas solution” for monetizing gas reserves by transporting wellhead gas, including gas liquids, from field to market.  The CGL® System cost-effectively loads, transports, and delivers the full produced gas stream to markets at distances from 50nm to more than 3000+ nm (93 km to more than 5556+ km).

The transportation portion of the System is made up of ocean-going vessels. The CGL Prodcut is loaded into a proprietary CGL® pipeline containment system that is integrated into specially designed and constructed ships or shuttle barges.

Currently the CGL® System technology designs provide the ability to transport and deliver CGL cargo volumes with a gas equivalence from 0.50 to 2.2 BCF (17.0 to 62.3 MMcm) per CGLC, or with a gas equivilence from 0.15 to 0.8 BCF (4.25 to 22.66 MMcm) per CGL® Shuttle Barge. The transport vessels will be sized to meet scheduled production and market delivery requirements.

The CGL® System can accept a wide variety of gas compositions directly from the field, minimizing costly field infrastructure and is a complete system and solution for conditioning, loading, transporting, storing, and offloading gas production.

Gas Loading Vessel
  • (FP(S)O). The GLV may be designed as a standard deep water steel hull or barge or may incorporate a bravity based design.
  • The full well stream (including gas liquids) is handled through modular design processes and equipment. The production conditioning and refrigeration systems, and the CGL® process systems operating pressure of 1,400 psig (100 bar) and temperature of -40°F (-40°C) are moderate.
  • A light hydrocarbon solvent is added to create the CGL   Product that is then loaded into the CGL® containment system.
  • H2S, sour gas or high CO2 can be handled by adding treating modules.
  • The Gas Loading Vessel and its processing facilities renders the traditional production platform approach (and costs) unnecessary.
  • The Gas Loading Vessel can be moved away before extreme weather conditions occur and is designed to operate in sea-state 6 conditions.
  • The Gas Loading Vessel is normally designed to operate through 10 year weather events.
  • The Mooring Systems are normally designed to operate through 100 year weather events.
  • Swing volumes can be handled by reducing production levels and/or having on board integrated storage.

Deep Water Steel Hull

Barge Hull

CGL Carriers

CGL® Shuttle Carrier (CGLC) Features

  • Hull design is that of an independent hull platform, similar to a container and heavy-lift ship design.  ABS Class Notation in accordance with IGC
  • Loading and offloading of CGL Product is done through flexible hoses or loading arms connected from the respective GLV or GOV.
  • The pipeline containment system is a continuous carbon steel pipe design that is housed inside a covered insulated cargo containment area where the temperature is maintained at -40°F/C.
  • The cargo containment system is fully liquid filled, with  no sloshing.
  • Carriers can be sized from 0.6 BCF to 2.2 BCF or (17.0 to 62.3 MMcm) with larger ships more cost efficient.
  • ABS and Lloyd’s Register have given Approval in Principle. ABS has been retained to provide Classification and Certification of the CGL® System Project Assets.


  • By adapting current, proven vessel designs, a CGL cargo can be efficiently transported over a wide range of cargo volumes and distances
  • Vessel designs can be optimized for best combination of cargo volume and speed to suit specific project requirements.
  • Vessels can be designed to operate over a wide range of sea conditions.
  • The final hull designs will be based on project specific criteria including environmental, and a comprehensive model test program.

Articulated Tug and Barge (AT/B)

AT/B – Articulated Tug and CGL® Shuttle Barge Features

  • Vessels employ an articulated connection system with the tug mating into a specially designed notch in the stem of the CGL® Shuttle Barge.  The design allows for the tug screws to remain in the water under changing sea conditions.
  • The articulated tug-barge design (AT/B) has been employed on numerous ocean-going units and provides significant improvements in maneuvering, speed and operating limits.
  • The AT/B concept provides the operator with the ability to shuttle multiple barges with a single tug unit, greatly reducing crew requirements and operating costs.
  • CGL® Shuttle Barges are equipped with bow thrusters controlled from the tug which provide for unassisted maneuvering to the loading and offloading vessels/terminal.
  • CGL® Shuttle Barges are designed to be double hulled and the tugs are double sided for maximum protection and safety. Barges are designed to be built, documented and maintained to the requirement of American Bureau of Shipping (ABS).
  • Tugs are designed to meet all SOLAS (Safety of Life At Sea) and ABS criteria, and will have foam and water deluge fire monitors. Tugs are equipped with twin fuel efficient, low emission electronic diesel engines. Vessels can also be powered by dual fuel engines.
  • AT/B units can be sized from 0.15 BCF to 0.8 BCF (4.25 to 22.66 MMcm) cargos.

AT/B Operational Advantages

  • Reduced crew size
  • Schedule flexibility (one tug can service multiple CGL® Shuttle Barges)
  • Lower maintenance
  • Tugs can perform lighter operations
  • Wide range of sea conditions
  • Fuel savings enhanced by wheel and rudder efficiencies
  • Tug engagement allowed regardless of draft or trim
  • Good maneuverability at sea and in port

Gas Offloading Vessel

  • SeaOne’s proprietary designs for the Gas Offloading Vessel permit it to be classified as a floating production, storage, and offloading vessel (FP(S)O). The GOV may be designed as a standard deep water steel hull or barge or may incorporate a gravity base design.
  • Modular topsides are designed to meet market conditions. Compression, liquids handling and swing volumes are sized for production and processing needs.
  • The CGL cargo is unloaded from a CGLC or CGL shuttle Barge onto the GOV.
  • The purpose of the Gas Offloading Vessel is to provide the market with either client specified gas quality and/or fractionated products.
  • Deliveries can be made at an offshore Deep Water Port or, into an existing gas plant or storage for later processing.
  • Onshore storage capacity and processing can be provided as an option.
  • No land based regas facility is needed, greatly decreasing permitting requirements.
  • The vessel can be moved in response to severe weather conditions.
  • The Gas Offloading Vessel is normally designed to operate through 10 year weather events.
  • The Mooring Systems are normally designed to operate through 100 year weather events.
  • Swing Volumes can be handled by having on board integrated storage.
  • Offloading hubs could eventually handle multiple projects (hub and spoke).

Deepwater Steel Hull

Barge Hull


  • The CGL System provides for at least two thirds less emissions and energy consumption due to moderate liquefaction pressures and temperatures.  This provides a small carbon footprint.
  • All operating assets in the CGL system can operate on natural gas.
  • If a release occurs of the CGL cargo, it vaporizes immediately with minimal negative environmental impacts.
  • Further benefits exist through monetization of existing flare gas projects.