After natural gas is produced from a well and initial separation has taken place, it
will travel through a gas meter to measure the production.
These meters may be on a separation vessel monitoring production volumes, or they are
used for custody transfer, where the gas is measured, and a midstream company takes ownership
of it.
In this video, I’m going to show you four types of gas meters.
Hi, I’m Kyle with Kimray, where we help energy producers solve their biggest control
challenges.
Producers use several types of flow meters depending on their gas volume and fluid properties.
Each meter measures the flow rate, but the operation and methods of measuring are different.
Each one of these meters can be used in both upstream production and midstream transportation.
In upstream production, they can be used to monitor individual well production, custody
transfer at a sales meter or to meter the amount of chemicals being injected.
In the midstream, they can be used for inventory measurement, process control, fuel management
and regulatory reporting.
The first one we’ll talk about is a mass flow meter.
The mass flow rate is the amount of liquid that passes through a meter over a given unit
of time.
A mass flow meter measures this rate and is dependent on the density and velocity of the
liquid and the size of the meter.
The Coriolis meter is the most common mass flow meter used in the oil and gas industry.
Using motion mechanics, it splits the process fluid into two tubes oscillating in opposite
directions.
Voltage is generated by vibrations, sine waves are created, and the time delay in motion
A thermal mass flow meter measures the fluid volume based on the heat transfer or temperature
change, from a heated element positioned in the flow stream.
The more fluid that passes around it, the faster it cools, indicating greater flow volumes.
Thermal mass flow meters provide excellent accuracy and repeatability.
The next type of flow meter we’ll talk about is a velocity meter.
With this type of meter, the velocity of the fluid passing through it determines the measurement.
The most common velocity meter is a Turbine flow meter, which calculates flow based on
fluid flowing through a free-spinning rotor.
Each revolution of the rotor is read by a magnetic pickup and corresponds to a specific
volume of gas or liquid.
Because of the moving parts and operation, turbine meters are limited to single-phase
fluids, such as dry gas or liquid.
To compensate for varying applications, pressure and temperature, those variables must be imputed
into the flow monitor to calculate accurate measurement.
Vortex flow meters operate under the vortex shedding principle, where an oscillating vortex
occurs when a fluid flowing past a bar positioned in the flow path generates a frequency that
can be read by the meter.
Because there are no moving parts, it is ideal for applications where low maintenance costs
are important.
Ultrasonic flow meters measure the difference in pulses transit time that travels from the
upstream transducer to the downstream sensor and vice versa.
Ultrasonic meters are highly accurate but very expensive and require extra input for
pressure and temperature.
The third type of flow meter we’ll talk about is a pressure differential meter.
A pressure differential meter operates by measuring a pressure drop across a fixed obstruction
inserted into the fluid flow path.
Orifice plates and venturi tubes both operate off pressure differentials.
Both orifice plates and venturi tubes operate by restricting flow, which causes the pressure
to drop.
The pressure on the upstream and downstream sides of the meter is measured using pressure
transducers.
The pressure differential that’s created allows flow monitor to determine the flow
rate using Bernoulli’s Equation.
Temperature and pressure must be considered for accurate measurements.
The final type of flow meter used in oil and gas is the Positive displacement meter.
Positive displacement meters use fluid to displace mechanical components to measure
volumetric flow.
Compensations for the operating temperatures and pressures are needed for accurate measurements.
The most common type of positive displacement meter is a diaphragm meter, which can be found
outside of most houses to meter the natural gas usage for utility companies.
Thanks for watching.
We hope this helps you better identify and understand the types of meters found in oil
and natural gas production.
To speak with an expert about metering or any other upstream oil and gas application,
contact our Kimray Product Applications team.