Sonic measurement of flow rate and water content of oil-water streams
AssigneeContinental Oil Company
InventorsJohn D. Alexander, Philip W. Reed
Life of this patent
Estimating the term…
Abstract
A method and apparatus for metering water content in an oil-water system by measuring sonic velocity in a flowing oil-water mixture, thereafter to determine flow rate to provide individual oil and water rates which may then be integrated to provide oil and water volume of flow. The apparatus functions to provide continual readout of oil and water data by deriving bi-directional speed of sound through the moving medium with subsequent frequency difference processing to derive sonic velocity, flow rate measurement and subsequent integral data output.
Claims9
A method of determining quantitative and volumetric data of an oil-water mixture flowing through a conduit of predetermined cross-sectional size, comprising the steps of:
- providing in said conduit a metering section of the same cross-sectional size and deriving therein by use of a sonic flow meter with the speed of sound of sonic energy transmitted through the flowing oil-water mixture by determining both an upstream frequency and a downstream frequency of ultrasonic energy transmitted through the flowing oil-water mixture, deriving from said upstream and downstream frequencies and average frequency which varies in direct proportion to the percent water cut from 0 to 100 percent, and deriving from said upstream and downstream frequencies the difference frequency which varies in direct proportion to the rate of flow of flowing oil-water mixture;
- and
- placing upstream of the metering section mixing and turbulence-reducing elements within the flowing oil-water mixture;
- and
- comparing the derived sonic frequency relative to a proportional empirically derived range of sonic frequencies to determine the percentage of water and oil which is present in the flowing oil-water mixture;
- and
- further characterized to include the steps of:
- sensing proximate the metering conduit section, the temperature of the oil-water mixture for indication of temperature correction factor;
- and
- applying all derived parameters of the flowing oil-water mixture, which includes temperature, velocity of sound energy through the flowing oil-water mixture, and the upstream and downstream frequency difference, for data input to a digital computer and subsequent processing to derive water content of the flowing oil-water mixture over the range from 0 to 100 percent water, as well as flow rate for individual oil and water rates and time-integrated data indicating oil and water volumes.
Apparatus for determining the oil and water content in an oil-water mixture flowing through a closed conduit system, comprising:
- a metering conduit section of known cross-sectional size inserted in said conduit system;
- a fluid mixer conduit section inserted in said conduit system upstream from said metering conduit section;
- means attached to said metering conduit section for determining upstream and downstream frequency of sonic energy transmitted at predetermined frequency through said flowing oil-water mixture;
- means for converting the upstream and downstream frequency signals to an analog voltage indicative of average frequency which analog voltage varies in proportion to the speed of sound in the mixture;
- and
- means for indicating said analog voltage relative to the calibrated limits of the speed of sound within an oil-water mixture which may vary from zero to one hundred percent water cut.
Dependencies are inferred from the claim text.