Radiant energy – Invisible radiant energy responsive electric signalling – Flow metering
Patent
1995-01-06
1997-08-05
Fields, Carolyn E.
Radiant energy
Invisible radiant energy responsive electric signalling
Flow metering
7386104, 378 51, G01F 100
Patent
active
056545517
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to measurement of fluid mass flowrates in a multiphase slug flow containing at least two liquid phases.
BACKGROUND ART
As used herein the term "phase" is intended to refer to separate immiscible liquid phases such as oil and water as well as liquid and gas phases. As used herein the term "multiphase" is intended to refer to a mixture including at least two such phases. The term "slug flow" refers to the slug or plug flow regime of the kind that occurs in pipelines from oil wells carrying the three-phase mixture of oil, water and gas. These flows are characterised by intermittent but well defined slugs of water, oil and gas mixtures which essentially fill the cross section of the pipeline. These slugs are separated by what are termed films, which are portions of the flow in which the pipeline is substantially filled with gas accompanied by a small amount of mixed water and oil.
The mass flow rate measurement of the oil, water and gas from individual oil wells is important for better reservoir management, better production allocation, and optimisation of total oil production over the field life. Normally, the required accuracy of determination of mass flow of each phase is 5%.
Additionally, there is often a need to measure the relative concentrations of oil and water in a flow after separation of the gas and some of the water. This measurement can present considerable practical difficulty particularly where the densities of the oil and water are the same or similar.
Current practice for the measurement of mass flowrate of the phases of oil well flows is to periodically physically divert the well output to a test separator. After separation the flow rate of each component is measured with conventional devices such as orifice or turbine flow meters. There are several inherent disadvantages associated with this technique. Firstly, accurate measurement requires stabilised well flow which can take some time to establish. Often, testing the output of a single well may take a whole day. In addition, the physical size of the separator and associated equipment occupies significant space which can lead to increased costs on off-shore platforms. Finally, in practice it is not feasible to provide each well with its own test separator system and often many wells share a common facility. Continuous monitoring of the output of each well is therefore not possible.
Various techniques have been suggested for on-line mass flow measurement of multiphase mixtures. Most depend on determination of the concentration of one or more of the phases coupled with a determination of either the mean velocity of one or more of the phases or the total mass flow of the mixture. Concentration measurement by capacitance is described in a paper entitled "On-line measurement of oil/water/gas mixtures using a capacitance sensor" by Beck M. S. Green R. G., Hammer E. A. and Thorn R., Measurement 3 (1) 7-14 (1985). Measurement of component concentration using a dual energy gamma-ray transmission technique has also been described by the following: parameters by gamma-ray transmission analysis, pp. 539-550 in Nuclear Techniques and Mineral Resources 1977, IAEA, Vienna, 1977. volume of a multiple-component mixture, U.K. Patent Application GB2083908 A, 1982. ratios in multiphase systems using gamma-ray attenuation, J. Phys. E.: Sci. Instrum, 131 341-345 (1980). Patent Application GB 2088050 A, 1982. gamma-ray oil/water/gas fraction meter for crude oil production systems, Paper presented at the International Conference on Industrial Flow Measurement On-shore and Off-shore, 22-23/9/87, London.
Microwave measurement of phase concentration is also known from U.S. Pat. No. 4,301,400. Neutron inelastic scatter techniques have also been used.
Energy transmission techniques for measurement of phase concentration, in which the radiation source is on the opposite side of the pipe from the radiation detector, have the advantage over reflection or scatter techniques of being sensitive to fluid volumes right across the pipe
REFERENCES:
patent: 4205230 (1980-05-01), Stubbs
patent: 4210809 (1980-07-01), Pelavin et al.
patent: 4228353 (1980-10-01), Johnson
patent: 4520677 (1985-06-01), Macko et al.
patent: 4539649 (1985-09-01), Michaelis et al.
patent: 4683759 (1987-08-01), Skarsvaag et al.
patent: 4835390 (1989-05-01), Blatchley et al.
patent: 5025160 (1991-06-01), Watt
patent: 5121639 (1992-06-01), McShane
patent: 5287752 (1994-02-01), Den Boer
J.S. Watt et al., "Progress Towards a Mass Flow Meter for Oil, Water and Gas", pp. 1-6 (1991), Offshore Australia Conference, Melbourne.
J.S. Watt et al., Nucl. Geophys., 5, No. 4, pp. 469-477 (1991), "Determination of Flow Velocity . . . Gamma-Ray Transmission".
M.D. Rebgetz et al., Nucl. Geophys., 5, No. 4, pp. 479-490 (1991), "Determination of the . . . Energy Gamma-ray Transmission".
Division G1 No. 1595973, "Flow Sensor", 21 Mar. 1978.
Division G1 No. 1340654, "Photoelectric fluid flowmeters", 30 May 1972.
Divisions 113 115, No. 1398381, "Correlation of noise-modulated signals", 2 Jun. 1972.
Watt John Stanley
Zastawny Henryk Wojciech
Commonwealth Scientific and Industrial Research Organisation
Fields Carolyn E.
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