Fuel Oil Custody Transfer - avoiding claims and disputes
Custody Transfer in the oil and gas industry refers to the transactions of a physical substance from one operator to another. This includes the transferring between tanks and tankers; tankers and ships and other transactions.
Custody transfer generally involves:
• Industry standards
• National metrology standards
• Contractual agreements between parties
• Government regulation and taxation
Custody transfer requires an entire metering system that is designed and engineered for the application, not just flowmeters.
Typical System Components include:
• Multiple meters
• Flow computers
• Quality systems
• Calibration units e.g. master-meter
The Custody Transfer System is customized to match the requirements of the application.
Depending on volume, site requirements and layout we will design a system to fit the task.
Custody Transfer - System Description
The Go4 Custody Transfer System follow the guidelines set by ISO.
By industrial consensus, liquid flow measurement is defined as having an overall uncertainty of ±0.25% or better. Go4 PD meters are ± 0,1% or better.
Sampling
An automatic flow-proportional sampling system should be used to determine the average water content and average density for analysis purposes. The sampling system is a critical section during flow measurement. Any errors introduced through sampling error will generally have a direct, linear effect on the overall measurement.
Temperature
Temperature measurement points are situated close to the meters and because measurements affect the accuracy of the metering system they have a loop accuracy of 0.5°C or better, and the corresponding readout has a resolution of 0.2°C or better.
Temperature checks are performed by certified thermometers.
Pressure
Pressure measurements affect the accuracy of the metering system and has an overall loop accuracy of 0.5 bar or better and the corresponding readout has a resolution of 0.1 bar or better.
Go4 PD Flow Meters
PD Meters
During custody transfer, accuracy of the quantity is of great importance to both the company delivering the material and the actual recipient.
For this purpose Positive displacement (PD) flowmeters, which are highly accurate meters are widely used for custody transfer of many liquids and have been approved by a number of regulatory bodies for this purpose as PD meters excel at measuring low flows, as well as measuring highly viscous flows.
Because PD meters captures the flow in a container of known volume, flow speed does not matter when using a PD meter.
