What is a Metering Skid? Its Working Principle and Importance in the Energy Industry
In the energy industry, such as oil, natural gas, and petrochemicals, the accurate measurement of liquid and gas flow is crucial for safety, quality, and economic value. Billions of dollars in energy transactions require reliable instruments. The device specifically designed for this task is the Metering Skid.
What is a Metering Skid?
A Metering Skid is a system for measuring the volume of liquids or gases, installed together on a single skid frame. It is designed for easy lifting, moving, and installation at the actual worksite. The skid contains measurement instruments, control devices, valves, and a piping system arranged according to standards to achieve accurate measurements compliant with international standards.
It is generally used for custody transfer (transfers related to commercial sales) and fiscal measurement (measurement for tax or financial purposes), which demand very high accuracy.
Main Components of a Metering Skid
The structure of a Metering Skid may vary depending on the type of fluid (liquid/gas), but it primarily consists of the following key components:
- Flow Meter: Such as Turbine Meter, Coriolis Meter, Ultrasonic Meter, used to measure flow rate.
- Control Valve and Isolation Valve: To safely control flow and shut off the system.
- Strainer / Filter: To trap dirt or solid particles from interfering with the measurement.
- Temperature & Pressure Transmitter: Used to measure temperature and pressure to correct the measurement results.
- Prover System (on some skids): Used to calibrate the accuracy of the meter.
- Flow Computer: The brain that collects data from all devices and calculates the measurement results according to API/ISO standards.
Working Principle of a Metering Skid
The operation begins with the fluid flowing through the piping system on the skid, passing through a flow meter selected for the fluid type. The data is then sent to transmitters and the flow computer to compensate for temperature, pressure, and density. The final result is highly accurate and can be used for legal or commercial contract verification.
Benefits of a Metering Skid
Having a Metering Skid increases confidence and transparency in the energy industry's operations, as every volume measurement is directly linked to economic value.
Main benefits:
- High accuracy, reducing financial discrepancies.
- Convenient to move and install as it is a pre-fabricated skid.
- Compliant with international standards (API, ISO, OIML).
- Enhances safety in measurement and flow control.
- Easy to maintain and calibrate.
Maintenance and Related Standards
To maintain accuracy, the Metering Skid must be calibrated periodically, referencing standards such as API MPMS (Manual of Petroleum Measurement Standards) or ISO 17025, to ensure the measurement results are correct and internationally acceptable.
Important maintenance includes:
- Regularly checking the operation of the Flow Meter and Prover.
- Cleaning the Strainer/Filter to prevent blockages.
- Verifying signals from the Pressure and Temperature Transmitters.
- Testing the Flow Computer system and data connections.
Conclusion
As mentioned, a Metering Skid is not just a set of pipes and meters, but a system that connects engineering, safety, and economic dimensions. Without the accuracy of this skid, massive oil or gas transactions could be flawed. Therefore, every energy industry places great importance on the meticulous design, installation, and maintenance of metering skids.
