Ship loading in the oil & gas industry

Custody transfer measurement of up and offloading processes

In the oil industry, the major product transported by sea has previously been crude oil. However, more and more refined products are also being transported by sea. Oil tankers deliver around 2.5 billion cubic meters of crude oil and refined products each year, and provide the next most efficient transport system after oil pipelines. Tanker sizes range from inland or coastal tankers that hold a few thousand cubic meters, up to ‘Ultra Large Crude Carriers’ (ULCC) that can hold up to 650,000 cubic meters. Tankers have different compartments and are often equipped with a marine tank monitoring and alarming system, such as the KROHNE CARGOMASTER, which uses radar-based level measurement sensors. Most tankers also have inert gas blanketing systems, using mainly nitrogen, that avoid the possibility of any explosive gas mixtures being present in the ullage space above the product.

Requirements
  • Continuous measurement to adjust level in the degasser
Requirements
  • Avoid damage to bearings of the pump
  • Indication of the flow
Requirements
  • High accuracy measurement of valuable products
  • Need for diagnostics to ensure measurement accuracy
Requirements
  • Control of the tank farm
  • Inventory measurement
Requirements
  • Maintenance of the non-explosive atmosphere
  • Low flows with mostly low pressures
  • Monitoring of minimum throughput
Requirements
  • Risk of overfill or dry run
  • Ensure continuous supply of crude oil or refined product
Requirements
  • Visualisation and monitoring of critical processes
  • Control of reporting, trends and alarm handling
  • Statistical evaluation of measurement data
Requirements
  • Integration of flow computers, PLCs, supervisory computers and printers
  • Installation of single flow computers up to fully redundant cabinet
  • Complying with custody transfer requirements
Requirements
  • Measurement of oil and refined product quality
  • Fully automated sampling during loading and unloading
  • Measurement of water content in oil
Requirements
  • Fully certified according to local and international metrology requirements
  • Lowest possible measurement uncertainty
  • High reliability and low maintenance
Requirements
  • High-accuracy measurement of volume and quality of oil and refined products
  • Traceable to international standards
  • Complying with custody transfer requirements
  • Master/duty configuration with flowmeter diagnostics

Applications

Custody transfer LNG ship loading and unloading
Application Report | Oil & Gas
  • High accuracy Coriolis mass flow measurement of LNG with a large flowrate
  • Complete custody transfer (CT) measuring system for cryogenic liquids
  • Continuous and consistent measurement results from start to finish even in the event of entrained BOG (Boil-off Gas)
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