Apparatus and method for measuring the flow-rate of different fluids present in multiphase streams

Patent metadata

Field	Value
Publication number	US-9377336-B2
Application number	US-201214112002-A
Country	US
Kind code	B2
Filing date	Apr 18, 2012
Priority date	Apr 19, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

The present invention relates to an apparatus and method for measuring the flow-rate of different fluids present in a plurality of distinct multiphase streams (C), in transit, each through a respective main flow pipe ( 2 ). The apparatus ( 1 ) comprises a measuring unit ( 3 ) for each pipe ( 2 ). Each measuring unit ( 3 ) comprises a sampling device ( 4 ). Each measuring unit ( 3 ) comprises first and second measuring means ( 5 ) of the differential pressure type situated downstream of the respective sampling device ( 4 ). The apparatus ( 1 ) comprises a phase separator ( 8 ) associated with the measuring unit ( 3 ). The apparatus ( 1 ) comprises selection means ( 18 ) interposed between the measuring unit ( 3 ) and the separator ( 8 ) for putting the latter in communication with one of the sampling devices ( 4 ) envisaged. The apparatus ( 1 ) comprises third measuring means ( 12 ) associated with the separator ( 8 ) for measuring the outgoing flow-rates of the different fluids separated and data processing means suitable for receiving and processing the data revealed by the measuring devices ( 5, 7, 12 ).

First claim

The invention claimed is:

1. An apparatus for measuring the flow-rate of different fluids present in a plurality of distinct multiphase streams, in transit, each through a respective main flow pipe which does not form part of said apparatus, said apparatus comprising:
at least one measuring unit operatively associated with each main flow pipe, each measuring unit coaxially intercepting a first portion and a second portion, consecutive, of the respective main flow pipe and comprising: a sampling device, in particular isokinetic, for the sampling of a predetermined quantity of a respective multiphase stream, suitable for separating said multiphase stream into a sampled fraction and a non-sampled fraction; first measuring means of the differential pressure between the sampled fraction and non-sampled fraction situated downstream of the respective sampling device; a flow restriction having a reduced passage section with respect to the passage section of the respective flow pipe, situated downstream of the respective sampling device; second measuring means of the differential pressure operatively associated with the respective restriction;
a separator device operatively associated with said measuring unit for separating the phases of the respective fractions sampled and collected from the corresponding sampling devices;
selection means operatively interposed between said measuring units and said separator device for putting the latter in fluid communication with a sampling device of at least one of said measuring units, said selection means being commutable at least between an exclusion condition, in which the sampling device of each of the measuring units envisaged is not in fluid communication with said separator device, and a selection condition, in which at least one of the measuring units envisaged, is in fluid communication with said separator device, whereas the sampling device of the other remaining measuring units is not in fluid communication with said separator device;
third measuring means operatively associated with said separator device for measuring the outgoing flow-rates of the different fluids present in the respective sampled fraction, said third measuring means being operatively arranged between said separator device and a joining connection of the fluids separated;
regulation means, operatively positioned downstream of said joining connection, to control the flow-rate sampled by the respective sampling device of the respective measuring unit in fluid communication with said separator device;
data processing means suitable for receiving and processing the data collected from said first and second measuring means of each measuring unit, from said third measuring means of said separator device and from said regulation means situated downstream of said joining connection, said data processing means being suitable for sending operative signals to said regulation means for varying the flow-rate of the sampled fraction in each sampling device of each measuring unit, said data processing means commanding the selection means between the exclusion condition and the selection condition.

2. The apparatus according to claim 1 , comprising: at least one feeding duct of said fractions sampled by the sampling device of each measuring unit, interposed between said separator device and said measuring unit; a tapping pipe for each measuring unit extending from the sampling device of the respective measuring unit and in fluid communication with said separator device through said feeding duct, said selection means comprising, for each measuring unit, at least one flow valve operatively situated along the respective tapping pipe upstream of said feeding duct of said separator device.

3. The apparatus according to claim 1 , comprising, for each main flow pipe envisaged, a respective conveying duct in fluid communication with said joining connection, each conveying duct being equipped with at least one valve commutable between a closed condition, in which it blocks the respective conveying duct, and an open condition, in which it allows the passage of the fluids coming from said joining connection towards the respective main flow pipe.

4. The apparatus according to claim 1 , wherein the sampling device of each measuring unit is suitable for collecting from each multiphase stream an aliquot, variable from ⅕ to 1/10 of a predetermined ideal maximum flow-rate, whereby the aliquot collected varies in relation to the flow-rate of each multiphase stream.

5. A method for measuring the flow-rates of each phase in a plurality of distinct multiphase streams which are flowing in respective and different main flow pipes, said method comprising:
collecting a predetermined quantity of flow-rate of a respective multiphase stream from a section of an area of one of said main flow pipes, in which substantially isokinetic conditions are verified, the collection of said quantity of flow-rate being effected by means of a respective isokinetic sampling device;
putting the respective sampling device in fluid communication, by means of a hydraulic connection, with a separator device for separating the phases of the quantity of flow-rate collected, the connection between the sampling device selected and the separator device, being effected excluding the hydraulic connection between the sampling device applied to the other main flow pipes and the separator device;
measuring the flow-rate of each phase separated in the separator device;
joining the phases separated after measuring the flow-rate of the same;
introducing the joined phases into the respective main flow pipe;
the connection between the sampling device selected and the separator device being effected by commuting a respective valve, hydraulically interposed between said separator device and the sampling device associated with the respective main flow line.

6. The method according to claim 5 , wherein the sampling phase of a predetermined quantity of flow-rate of a respective multiphase stream comprises a phase for collecting from each multiphase stream an aliquot, variable from ⅕ to 1/10 of a predetermined ideal maximum flow-rate, whereby the aliquot collected varies in relation to the flow-rate of each multiphase stream.

Assignees

• Boschi Stefano
• Andreussi Paolo
• Eni Spa

Inventors

• Boschi Stefano
• Andreussi Paolo

Classifications

• E21B47/10

  Locating fluid leaks, intrusions or movements · CPC title

• G01F1/74 Primary

  Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid · CPC title

• G01F1/36 Primary

  the pressure or differential pressure being created by the use of flow constriction · CPC title

• G01N33/2823

  Raw oil, drilling fluid or polyphasic mixtures · CPC title

• G01F15/08

  Air or gas separators in combination with liquid meters; Liquid separators in combination with gas-meters · CPC title