Method and apparatus for flow measurement
AssigneeSensor Highway Limited
InventorGeorge A Brown
Life of this patent
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Abstract
A method and apparatus is disclosed for measuring the flow of fluid in the conduit, giving the example of oil in a well bore (12). A heat exchanger such as a cooling station (66) is placed in the well bore (12) and caused to create a slug of cooled oil whose passage, through the well (12) can be monitored by a temperature sensor in the form of a continuous fiber optic loop (62). Knowledge of the movement of the cooled slug of oil and of the free cross-section of the conduit (54) wherein the oil is flowing permits the volume flow-rate of oil to be calculated. Cooling stations (66) are cooled by Joule-Thompson cooling employing high pressure nitrogen gas. Cooling stations (66) may be placed at plural locations within the well bore (12) to monitor individual flows (68) from multiple flow sources.
Claims36
An apparatus for measuring fluid flow in a conduit, said apparatus comprising:
- a temperature sensor for measuring and providing indication of the temperature of the fluid at at least first and second temperature measuring points spaced by a known distance along the conduit;
- a heat exchanger selectably operable to alter the temperature of the fluid upstream from said temperature measuring points;
- and a timer, responsive to said output of said temperature sensor to measure the time difference of arrival of the temperature altered fluid at said first and second temperature measuring points.
An apparatus, according to any of the preceding claims wherein said fluid is water.
An apparatus, according to any of the preceding claims, for use where the conduit has a plurality of flow sources, said apparatus comprising:
- a plurality of heat exchangers, each heat exchanger being downstream from a respective flow source;
- said temperature sensor being operative to measure and indicate the temperature at respective first and second points downstream from each heat exchanger;
- and said timer being operative to measure the time difference of arrival of temperature altered fluid at each respective pair of said first and second temperature measuring points.
An apparatus, according to any of the preceding claims, for use where the cross-sectional area of the conduit is known, said apparatus comprising computation means to calculate the volume rate of flow past said heat exchanger or heat exchangers.
A method for measuring fluid flow in a conduit, said method comprising the steps of:
- measuring the temperature of the fluid at at least first and second temperature measuring points spaced by a known distance along the conduit;
- altering the temperature of the fluid upstream from said temperature measuring points;
- and measuring the time difference of arrival of the temperature altered fluid at said first and second temperature measuring points.
An apparatus, substantially as described, with reference to the appended drawings.
A method, substantially as described, with reference to the appended drawings.
Dependencies are inferred from the claim text.