Detection of Impulse Line Blockage with Multi-sensing Differential Pressure Transmitter at Oil Line

Abstract

Differential pressure transmitter with an orifice is widely used as a major field flowmeter. Most of the trouble of this flowmeter on the operation site is blockage of impulse line, which connects an orifice tap with a differential pressure transmitter. In this paper, firstly, the relation between the pressure fluctuation in the impulse line to oil flow and kinetic viscosity (1.0x10-5 to 3.0 x 10-5 [m2/s]) is investigated as well as the relation between the pressure fluctuation and operating condition. Then, our method of the impulse line blockage developed through experiments in a water line is applied to an oil line. The effectiveness of our detection method with multi-sensing differential pressure transmitter to the oil line is shown. As a result, following facts are clarified : 1) High viscous fluid contained in impulse line does not reduce each pressure fluctuation at the differential pressure transmitter. 2) High viscous flow has small pressure fluctuation, however, this fluctuation has the same characteristics of impulse line blockage as that in a water line. Therefore, our method can detect impulse line blockage at any operating points in high viscous fluid line as well as in a water line.