Separation of two fluid immiscible phases for downhole applications

Patent metadata

Field	Value
Publication number	US-11180396-B2
Application number	US-201113976322-A
Country	US
Kind code	B2
Filing date	Dec 28, 2011
Priority date	Dec 29, 2010
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

The present invention relates to a group and method for the separation of a mixture comprising two fluid phases mutually at least partially immiscible and with different specific density characterized in that it comprises a closed chamber ( 11 ) which extends between an upper outlet mouth ( 12 a ) of a fluid phase with lower specific density separated from the mixture, positioned at a first upper height, and a lower outlet mouth ( 12 b ) of a fluid phase with greater specific density separated from the mixture, positioned at a second lower height with respect to the first upper height, an inlet ( 15,33 ) for said mixture inside said closed chamber ( 11 ) also being present at a height interposed between said upper and lower heights, a first upper gross separation device ( 13 ) of said mixture and a second lower fine separation device ( 14,14 ′) of said mixture, hydraulically connected to each other ( 13 ) ( 14 ), being situated in succession, inside said closed chamber ( 11 ), between said upper outlet mouth ( 12 a ) and said lower outlet mouth ( 12 b ), the first upper gross separation device ( 13 ) comprising a gravitational separation chamber and the at least second lower fine separation device ( 14,14 ′) comprising at least one coalescence separator ( 14 ) and/or at least one hydrocyclone separator ( 14 ′).

First claim

The invention claimed is:

1. A downhole separation group for a mixture of two fluid phases consisting of an oily phase with lower density and an aqueous fluid phase with greater density, the downhole separation group comprising:
a closed chamber which extends between an upper outlet mouth for the oily phase with lower density separated from said mixture, positioned at an upper height, and a lower outlet mouth for the aqueous fluid phase with greater density separated from said mixture, positioned at a lower height with respect to said upper height;
an inlet for said mixture inside said closed chamber also being present at an interposed height between said upper and lower heights;
an upper gross separation device comprising a gravitational separation chamber which separates said mixture into a first portion of an oil-enriched phase and a grossly deoiled aqueous phase still containing small quantities of oil;
a lower fine separation device of said grossly deoiled aqueous phase, the lower fine separation device comprising at least one coalescence separator to further separate the grossly deoiled aqueous phase into a finely deoiled aqueous phase with greater density and a second portion of an oil-enriched phase of lower density, wherein the upper gross separation device and the lower fine separation device are hydraulically connected to each other in succession inside said closed chamber between said upper outlet mouth and said lower outlet mouth;
wherein said coalescence separator comprises a hollow tubular body equipped with a plurality of introduction holes distributed on the side surface of said hollow tubular body, said plurality of introduction holes being in fluid connection with said gravitational separation chamber for the introduction into said hollow tubular body of said grossly deoiled aqueous phase, at least one set of coalescence plates arranged mutually parallel one upon the other being housed inside said hollow tubular body and coaxially to the same, each of said coalescence plates with truncated-conical form, internally hollow and being open in correspondence with the larger base and smaller base, each of said coalescence plates being positioned with said larger base and said smaller base respectively facing an end of said hollow tubular body at a lower height and an end of said hollow tubular body at an upper height so as to define a lower edge and an upper edge with a circular profile, said at least one set of coalescence plates being housed in said tubular body so as to define a distribution channel of said grossly deoiled aqueous phase to be separated configured with an annular interspace between said lower edge of said coalescence plates and the internal side surface of said hollow tubular body, said at least one set of coalescence plates also defining, centrally with respect to said coalescence plates, an outflow channel of said finely deoiled aqueous fluid phase with greater density and at least a fraction of said second portion of an oil-enriched fluid phase with lower density in fluid communication with an outflow duct inside and coaxial to said outflow channel, said outflow duct terminating in an upper emission mouth and a lower emission mouth respectively, for the discharge of said phases with lower and greater density finely separated, said lower emission mouth being in fluid communication with said lower outlet mouth and said upper emission mouth being in fluid communication with said gravitational separation chamber,
wherein the upper edge of each of said coalescence plates extends into a lip folded towards the inside of said truncated cone so as to define a groove with the surface of the truncated cone, in correspondence with which the separated phase with lower density accumulates and contemporaneously favoring the outflow of the finely deoiled aqueous phase with greater density, and wherein the lip defines a curvature along which there is a crown of detaching pass-through holes of said second portion of an oil-enriched fluid phase with lower density; and

a conveyance tube of the oil-enriched fluid phase with lower density extending from said upper outlet mouth through said gravitational separation chamber and connecting below with said lower fine separation device, said conveyance tube of the fluid phase with lower density having at least one hole to convey said first and second portions of an oil-enriched phase towards said upper outlet mouth.

2. The separation group according to claim 1 , wherein said inlet is situated in correspondence with said gravitational separation chamber.

3. The separation group according to claim 1 , wherein said closed chamber is laterally delimited by a tubular casing, inside said tubular casing is said conveyance tube of the fluid phase with lower density, and said gravitational separation chamber defined by said tubular casing and said conveyance tube of the fluid phase with lower density, has an annular section.

4. The separation group according to claim 1 , wherein said upper emission mouth is in fluid communication with said gravitational separation chamber through said conveyance tube of the fluid phase with lower density.

5. The separation group according to claim 1 , wherein said upper emission mouth is in fluid communication with said gravitational separation chamber through a side duct outside said coalescence separator.

6. The separation group according to claim 1 , further comprising pumping means suitable for collecting said fluid phase with greater density finely separated, from said lower emission mouth and sending it through said lower outlet mouth.

7. The separation group according to claim 1 , wherein said pumping means are enclosed inside a containment chamber of the pumping means situated downstream of said coalescence separator with respect to the flow of said fluid phase with greater density, and in fluid connection with said lower emission mouth.

8. The separation group according to claim 1 , further comprising pumping means interposed between said gravitational separation chamber and said coalescence separator suitable for collecting said grossly deoiled aqueous phase from said gravitational separation chamber and sending it inside a containment chamber of said coalescence separator.

9. The separation group according to claim 1 , wherein said lower fine separation device further comprises a hydrocyclone separator.

10. The separation group according to claim 9 , wherein said hydrocyclone separator comprises a hollow tubular body which has a first cylindrical portion with larger diameter situated at an upper height and a second cylindrical portion with smaller diameter situated at a lower height connected by a third portion with tapered conformation, at least one introduction mouth tangential to the inner wall of said tubular body being provided in said hollow tubular body, in fluid connection with said gravitational separation chamber for the introduction into said hollow tubular body of a mixture previously grossly separated, said hollow tubular body comprising an upper emission mouth and a lower emission mouth respectively for the discharge of said phases with lower and greater density finely separated, said upper emission mouth being in fluid connection with said gravitational separation chamber, said lower emission mouth being in fluid connection with said lower outlet mouth.

11. The separation group according to claim 10 , wherein said upper emission mouth is in fluid connection with said gravitational separation chamber through said conveyance tube, and that said lower emission mouth is in fluid connection with said lower outlet mouth through the interpositioning of pumping means.

12. A method for the sepa

Assignees

• Andreussi Paolo
• Direnzo Domenico Antonio
• Eni Spa

Inventors

• Andreussi Paolo
• Direnzo Domenico Antonio

Classifications

• B01D17/0211 Primary

  with baffles · CPC title

• E21B43/385

  by reinjecting the separated materials into an earth formation in the same well · CPC title

• B01D17/045

  with coalescers · CPC title

• C10G33/06

  with mechanical means, e.g. by filtration · CPC title

• C02F9/00 Primary

  Multistage treatment of water, waste water or sewage · CPC title