TECHNOLOGIES FOR THE DEPOSITS VOLUME ASSESSING USING REFERENCE LIQUIDS IN PIPELINES

Abstract

The gas-liquid mixture flow along an oil and gas field pipeline is a complex process, the parameters of which, as a rule, are not determined along its length. Pressure and temperature of water-oil emulsion decrease along the pipeline length, pressure and temperature conditions of separation from oil both light components in the form of associated petroleum gas and heavy components – in the form of asphaltenes, resins, paraffins and mechanical impurities – change. Two techniques for deposit quantitative diagnostics  in the pipeline are discussed in the article. Viscosity and velocity of injected reference fluid in the pipeline section  complicated by deposits are considered as informative parameters when using pressure sensors and ultrasonic flowmeter. Technologies for the quantitative assessment of deposits in oilfield pipelines based on the control of the movement of a fluid with a reference property different from the property of the pipeline fluid are proposed. According to the first technology, the viscosity of the liquid is changed and the pressure difference at the beginning and at the end of the pipeline with deposits is fixed in time. According to the second technology, the value of the increased velocity of fluid movement in places where the pipeline is narrowed due to the presence of deposits is measured. The theoretical basis of the processes occurring with liquids in pipeline transport is substantiated. With an increase in the viscosity of the reference liquid, the degree of compression of the liquid increases and, as a result, the frequency of vibrations of the liquid molecules increases. With a decrease in the viscosity of the reference liquid, the reverse picture is observed.