Method and apparatus for sonic velocity type water cut measurement
AssigneeConoco Inc.
InventorsPhilip W. Reed, John D. Alexander
Life of this patent
Estimating the term…
Abstract
In a method and apparatus for metering water content in an oil-water system by determining sonic velocities in the flowing oil-water mixture, and thereafter determining flow rate to provide individual oil and water rates which may then be integrated to provide oil and water volume of flow, the improvement comprising self-calibrating for salt content of the system water by measuring the speed of sound in the water phase only and utilizing the measured value in determinations of the system water cut.
Claims14
A method for self-calibrating a system for determining quantitative and volumetric data of an oil-water mixture flowing in a conduit, comprising the steps of:
- providing in said conduit a metering section for controlled entrapment of water only;
- offsetting said metering section below said conduit so that stoppage of the oil-water mixture flow causes liquid separation thereby to enhance water only presence in said metering section;
- deriving by sonic flowmeter the speed of sonic energy transmitted through said metering section when containing water only;
- deriving by sonic flowmeter the speed of sonic energy transmitted through said metering section when containing said oil-water mixture;
- and
- determining said quantitative and volumetric data of said oil-water mixture, said determination being based upon said speed of sonic energy through said metering section when containing said oil-water mixture and upon a calibration adjustment dependent upon said speed of sonic energy through said metering section when containing water only.
A method for self-calibrating a system for determining quantitative and volumetric data of an oil-water mixture flowing from a three phase separator tank having a water dump conduit and an oil dump conduit, said method comprising the steps of:
- placing a water metering section in the water dump conduit of said tank;
- placing a second metering section in the oil dump conduit of said tank;
- deriving by sonic flowmeter the speed of sonic energy transmitted through said water metering section during water dumps;
- deriving by sonic flowmeter the speed of sonic energy transmitted through said second metering section during oil dumps;
- determining volumetric data of said water flowing through said water metering section during said water dumps;
- determining quantitative and volumetric data of an oil-water mixture flowing through said second metering section during said oil dumps, said determination being based upon said speed of sonic energy transmitted through said second metering section during said oil dumps and upon a calibration adjustment dependent upon said speed of sonic energy transmitted through said water metering section during said water dumps;
- and
- totalizing the data determined for said water metering section and said second metering section to determine the watercut of the total oil/water system.
In apparatus for determining quantitative and volumetric data of an oil-water mixture flowing in a conduit, the improvement comprising:
- a metering section disposed in said conduit laterally offset from the main axis of said conduit;
- sonic flowmeter means, disposed generally axially in said metering section, for measuring the speed of sound in a liquid flowing therethrough;
- and
- means for periodically stopping flow of liquid through said metering section for a duration sufficient to allow oil and water separation.
In combination with a two-phase separator tank having a dump conduit for outputting an oil-water mixture, apparatus comprising:
- a metering section disposed in said dump conduit;
- sonic flowmeter means, disposed generally axially in said metering section, for deriving the speed of sound in a liquid flowing therethrough;
- means for periodically stopping flow of liquid through said metering section for a duration sufficient to allow derivation of the speed of sound in water only;
- and
- computation means receiving input data representing the speed of sound in water only and the speed of sound in the oil-water mixture to generate output data for volume of oil and water in the flowing mixture per unit time.
In combination with a three-phase separator tank having a water dump first conduit and an oil-water dump second conduit for outputting collected oil-water mixture, apparatus comprising:
- a first metering section disposed in said first conduit;
- sonic flowmeter means, disposed generally axially in said first metering section, for generating first speed of sound data output representing the speed of sound in water flowing therethrough;
- a second metering section disposed in said second conduit;
- second sonic flowmeter means, disposed generally axially in said second metering section, for generating second speed of sound data representing the speed of sound in the oil-water mixture flowing therethrough;
- and
- computation means receiving said first and second speed of sound data and generating output indication of the total volume of oil and water flowing through said three-phase separator tank.
Dependencies are inferred from the claim text.