Most compact and cost efficient instrument for each wellThe Abbon 3PM multiphase meter is entering its final stage of development. The patented technology will be a very robust and compact instrument to be placed on each oil well for continuous measurement of the produced oil, water and gas. The 3PM combines electrical impedance measurement with velocity determination and pressure drop measurement over a restriction designed within the meter unit.
Reliable measurement technology with new innovative system design
The differential pressure generating restriction is a centrally placed body serving several purposes. It gives the well-known pressure drop proportional to the product of the volume- and mass flow rate, also known as the Venturi effect. In addition it contains electrodes used for measuring the impedance resulting from the composition of the fluid passing it. In the opening between the body and the inner pipe wall of the pipe, there is a zone where a high degree of turbulence is created.
The effects of this turbulence are twofold; first that the three phases are well mixed, which is good for the fraction measurement (the percentage of oil, water and gas, respectively); secondly that any velocity difference between gas and liquid is reduced to a minimum, which is good for the estimation of the total flow velocity.
The electrodes placed on the central body have counter electrodes implemented into the inner wall of the meter housing so that the impedance between them can be measured. With the patented design of the Abbon 3PM, the distance between these electrode pairs is very short, which is beneficial for the sensitivity and the accuracy of the impedance measurements. There are two pairs of the mentioned electrodes. For the purpose of fraction measurements, one pair of electrodes would be sufficient, and in this case it is the absolute value of the impedance that is used. However, the velocity measurement requires two signals, and in this case it is the time varying nature of the impedance that is of interest. Two such time varying signals from ideally identical impedance sensors are subject to cross-correlation in order to determine the velocity of the flow.
All the measurement principles involved are described by well-defined mathematical relationships and they are combined into one system in order to determine the individual flow rates of the three phases.
Patented designIn December 2010, the Norwegian patent authority officially announced the patent for the ABBON 3PM concept.
No radioactive source
The meter is totally non-radioactive, which increase acceptance for multiphase meters at offshore and onshore facilities.
