CA2978307A1

CA2978307A1 - Fluids injection flow control device for use in oil wells

Info

Publication number: CA2978307A1
Application number: CA2978307A
Authority: CA
Inventors: Leoncio Del Pozo; Walter D. Daparo; Julio Carbonetti; Gabriel Fernandez
Original assignee: COMPANIAS ASOCIADAS PETROLERAS SA
Current assignee: COMPANIAS ASOCIADAS PETROLERAS SA
Priority date: 2016-12-23
Filing date: 2017-09-07
Publication date: 2018-06-23
Also published as: BR102017014404A2; EP3348784A1; AR107189A1; US20190136675A1; US20180179874A1

Abstract

A fluids injection flow control device for use in oil wells, aimed at maintaining, within an established range, the injection rate within a determined layer between two packers, corresponding to the puncture zone of an injection well, for causing a controlled pressure drop of the flow delivered to the determined layer while minimizing damage to the molecule of the viscous fluid. The device is axially coupled to a tubing string and consists of a plurality of modules each including a coil helically wound on a coil carrier.
The coil, which is connected to the pipe through which the fluid flows, causes a certain load drop in an initial control component (referred to as a side-pocket mandrel) comprising a tubing string that allows for axial tubing continuity and a pocket in which a short or long flow direction vane is selectively installed that determines the outflow towards the puncture zone by way of a transverse opening or to the next module's corresponding coil through transition tubing.

Description

Y:\CM001\5666 CA\CIPO\Spec Clms & Abstrct 170905.wpd FLUIDS INJECTION FLOW CONTROL DEVICE FOR USE IN OIL WELLS
Field of the Invention [0001] The present invention relates to the field of fluid injection in oil wells.
Background of the Invention

[0002] An injection well is a well used to force fluids underground, typically into porous rock formations such as sandstone or limestone, or into or below the shallow soil layer. The fluid may be water, wastewater, brine (salt water), or water mixed with chemicals.

[0003] Injection wells are at times used in natural gas and oil production.
Steam, carbon dioxide, water, and other substances may be injected into an oil-producing region in order to maintain reservoir pressure, heat the oil or lower its viscosity, allowing it to flow to a producing well in the vicinity.

[0004] It has been found that different layers within an oil-producing region may differ in the pressure required to force fluids into each layer. As a fluid tends to follow the path of least resistance, the difference in required pressure between layers may result in most or all of an injected fluid flowing into a layer or layers with a low required pressure and little or no fluid flowing into a layer or layers with a high required pressure.
Summary of the Invention

[0005] In one aspect, the present invention provides a means to control the flow from surface devices aimed at establishing selective control automatically in each layer while reducing the degradation of the polymer molecules which provide optimum viscosity.

[0006] In another aspect, the present invention provides a device capable of maintaining the injection flow rate within a predetermined range in a given layer of an injection well, by producing a controlled pressure drop by virtue of the fact that the different coil length combinations developed as well as their inner diameter enable different flow ratios vs. pressure differentials.

[0007] In another aspect, the present invention provides a fluids injection flow control device for use in oil wells aimed at maintaining an established range in the injection rate within a given layer between two packers, corresponding to the puncture zone of an injection well, causing a controlled pressure drop of the derived flow to said sector without damaging the molecule of the viscous fluid; said device, which is axially coupled to a tubing string, including a plurality of modules formed by an upper coil support onto which a primary coil is helically wound, initially connected to the pipe through which the fluid runs, causing a certain load drop in an initial control component known as a side-pocket mandrel, which consists of two main parts namely the tubing string that allows for axial tubing continuity and the pocket in which a short or long flow direction vane is selectively installed that determines the outflow towards the unit by way of a transverse opening or its passage to the next module's corresponding coil through transition tubing. The implementation of the device for each layer involves an upper module provided with a pipeline fluid intake port, as many intermediate modules as are deemed necessary interconnected via said transition tubing and an end module in which said outlet passage may or may not be blind.

[0008] Device embodiments of the present invention, which enable Q
injection flow rate control, reflect the concept that there are no fluid sources or basins within the control volume and that, pursuant to the Law of Conservation of Matter, the inflow of the bypass tube from the tubing is equal to the outflow, where the p1 pressure of said tube is in direct relation to the unit's p2 pressure.

[0009] Thus, as there is a relation between the Q flow that can be injected into the layer, the p1 tubing pressure and the pressure of layer p2, any increase or differential between both pressures would tend to increase or diminish the Q flow injected.

[0010] Accordingly, in orderto mitigate flow variations resulting from variances in the p1 - p2 pressure equilibrium, certain geometrical parameters can be acted on, being: the tube's inner diameter D (technically complex), or the length L of said tube, which is achieved through the modeling of the coils and their coupling and decoupling to successive modules, with the consequent respective increase or decline in load loss.

[0011] In this way, discrete changes can be achieved in length L, thereby maintaining the injection flow rate within the range set against changes in the pressure differential.

[0012] Embodiments of the present invention may be used for controlling the injection flow of viscous fluids, generally polymer chain based, in a specific layer of an oil injection well, causing a controlled load loss without affecting its rheological properties.
Summary of the Drawings

[0013] The drawings are not to scale.

[0014] Figure 1 is a schematic quasi-sectional side elevation view of an embodiment of the present invention having an upper module, intermediate module and lower module.

[0015] Figure 2 is a schematic quasi-sectional side elevation view of the embodiment shown in Figure 1 indicating flow from the upper module.

[0016] Figure 3 is a schematic quasi-sectional side elevation view of the embodiment shown in Figure 1 indicating flow from the intermediate module.

[0017] Figure 4 is a schematic quasi-sectional side elevation view of the embodiment shown in Figure 1 indicating flow from the lower module.

[0018] Figure 5 is an isolation perspective view featuring a coil and coil carrier section of the embodiment shown in Figure 1.

[0019] Figure 6 features an upper side pocket mandrel of the embodiment shown in Figure 1 with cross-section markings VII-VII, VIII-VIII and X-X.

[0020] Figure 7 is the cross-section view VII-VII indicated in Figure 6.

[0021] Figure 8 is the cross-section view VIII-VIII indicated in Figure 6.

[0022] Figure 9 is a version of the cross-section view X-X indicated in Figure 6, shown with a long flow direction vane.

[0023] Figure 10 is a version of the cross-section view X-X indicated in Figure 6, shown with a short flow direction vane.

[0024] Figure 11 features a lower side pocket mandrel of the embodiment shown in Figure 1 with cross-section markings XII-X11.

[0025] Figure 12 is a version of the cross-section view XII-XII indicated in Figure 11 shown with a long flow direction vane.

[0026] Figure 13 is a version of the cross-section view XII-XII indicated in Figure 11 shown with a short flow direction vane.

Detailed Description of Exemplary Embodiment with Reference to the Drawings

[0027] The constructive and functional characteristics of the present flow control device for fluid injection in oil wells invention, are shown by way of a preferred example of said device, as described in what follows and shown in the drawings.

[0028] Figure 1 shows a device (1) installed in a casing area between an upper packer (2) and a lower packer (3), which in this particular case consists of three modules, one upper module (4), an intermediate module (5), and a lower module (6); in which the first is connected to the tubing (7) from which it draws the fluid through an intake port (8) connected to the first coil (9), helically wound onto the coil carrier section (10) axially fixed to the body of the upper side pocket mandrel (11) whose side pocket (11B), which is specifically the first control component that establishes the continuity of the fluid to the next module or delivers it to the casing, receives said fluid from the coil (9), by means of a transition tube (12) and is connected below by means of another transition tube (12) to the coil (9) that is wound around the coil carrier of the intermediate module (5), which is fixed to the intermediate side pocket mandrel (11) provided with its respective side pocket, similar to the previous one (11B), which is connected below by the transition tube (12) with the coil (9) that is wound around the coil carrier of the lower module (6) which is fixed to the lower side pocket mandrel (13) provided with a side pocket with an outlet which may or may not be blind (13B).

[0029] Figure 2 shows how the side pocket (11B) of the upper module (4), has determined the flow of the fluid towards the unit, as indicated by the arrow, by means of a short flow direction vane as seen in Figure. 10.

[0030] In Figure 3 the side pocket (11B) of the upper module (4), by means of a long flow direction vane (14), as can be seen in Figure. 9, has determined the continuity of the circuit while the side pocket (11B) of the intermediate module (5), by means of the short flow direction vane (15), shown in Figure 10, has determined the fluid flow towards the unit as indicated by the arrow.

[0031] In Figure 4 the side pocket (11B) of the upper module (4), by means of the long flow direction vane (14) shown in Figure 9, has determined the continuity of the circuit; the side pocket (11B) of the intermediate module (5), by means of the long flow direction vane (14) shown in Figure 9, has determined the continuity of the circuit; and the lower side pocket (13B) of the lower module (6), by means of the short flow direction vane (15) shown in Figure 13, has determined the flow of the fluid towards the unit as indicated by the arrow.

[0032] Figure 5 illustrates how the upper module (4) is connected to the tubing (7) from which the fluid is drawn by a tapping or intake port (8) connected to a first coil (9) wound helically around a coil carrier section (10).

[0033] Figure 6 shows a side pocket mandrel (11), used in the upper or intermediate modules (4 or 5), consisting of a body (11A) that is aligned with the tubing and provided with an insulated housing into which the side pocket (11B) is welded that establishes the flow control.

[0034] Figure 7 is the cross-section marked VII-VII in the previous figure, showing the tubing conduit (7) and the side pocket (11B), in which cylindrical housing (110) the corresponding direction vane (14 or 15) is placed, providing a passage (11D) which integrates it with the circuit.

[0035] Figure 8 is the cross-section marked VIII-V111 in the previous figure, showing an outlet opening (11E) for the flow circulation to the unit.

[0036] A side pocket (11) provided with a long flow direction vane (14) isolating the passage (11D) from the outflow opening towards the unit (11E), determining the absolute continuity of the circuit towards the next module through said passage is illustrated in detail in Figure 9 (cross section X-X in Figure 6).

[0037] In Figure.10, on the other hand, a short flow direction vane (15) has been installed so that, although flow through the passage (11D) is enabled, a second flow stream is released into the opening (11E) in the direction of the unit.

[0038] Figure 11 shows a lower side pocket mandrel (13), used in the lower module, formed by a lower body (13 A) aligned with the tubing and provided with an insulated housing into which the lower side pocket (13B) is welded, that establishes flow control.

[0039] Figures 12 and 13 correspond to the section marked XII-XII in the previous figure.

[0040] As can be seen in Figure 12, the lower side pocket (13) is provided with a long flow direction vane (14) that isolates the blind output passage (13D) from the outflow opening towards the unit (13 E), determining absolute circuit completion.

[0041] In Figure 13, however, a short flow direction vane (15) has been installed so that, although the circulation is closed off by the passage (13 D) since it is blind, an end flow stream is released towards the opening (13 E) directed towards unit.

[0042] The fluids injection flow control device for use in oil wells described and exemplified herein falls within the scope of this application's protection, which is basically established by the text of the following claim sheets.

[0043] In this specification and the drawings, the following component descriptors and reference numbers are used:
device (1) upper packer (2) lower packer (3) upper module (4) intermediate module (5) lower module (6) tubing (7) intake port (8) coil (9) coil carrier section (10) upper side pocket mandrel (11) body (11A) side pocket (11B) cylindrical housing (110) passage (11D) outlet opening (11E) transition tube (12) lower side pocket mandrel (13) lower body (13 A) lower side pocket with an outlet (13B) blind lower output passage (13D) lower outflow opening towards the unit (13E) long flow direction vane (14) short flow direction vane (15)

[0044] The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

WHAT IS CLAIMED IS:

1. A fluids injection control device for use in oil wells for maintaining, within a desired range, a fluid injection rate of a determined layer between two packers, corresponding to the puncture zone of an injection well, characterized in that:
the device (1), which is axially coupled to a tubing string, consists of a plurality of successive modules comprising:
an upper module (4) formed by an upper coil carrier (10) onto which a primary coil (9) is helically wound, the primary coil (9) is connected to piping (7) through which the fluid flows, and the primary coil (9) leads to a side-pocket mandrel (11), comprising a tubing string (11A) that allows for axial tubing continuity and a pocket (11B) in which a short (15) or long (14) direction vane is selectively installed to direct flow towards:
the puncture zone by way of a transverse opening (11E); or a second coil (9) of a lower module (6) through transition tubing (12) wherein the lower module (6) conforms in design to the upper module (4), except that in the lower module (6) a pocket outflow passage (13D) may or may not be blind.

2. The device of claim 1, further comprising one or more intermediate modules (5) conforming in design to the upper module (4), interconnected between the upper module (4) and the Lower Module (6).

3. The device of claim 2, characterized in that a pocket (11B) of the upper and intermediate modules is a cylindrical tubular body fixed to the body of the mandrel (11) which defines tubing continuity but is isolated therefrom, the lower end of which is blind and the top end of which permits the insertion or removal of a long (14) or short (15) direction vane, said tubular cavity in fluid communication, in a middle section of the tubular cavity, with a parallel passage (11D) which connects its upper and lower ends to the transition tubes (12) of the adjacent modules, whereas, near its lower end, which may or may not be blind, the cylindrical housing has a transverse outlet opening (11E) directed at the puncture zone.

4. The device of claim 1 or 2, characterized in that a pocket (13B) of the lower module is a cylindrical tubular body fixed to the body of the mandrel (13) which defines tubing continuity but is isolated therefrom, the lower end of which is blind and the top end of which permits the insertion or removal of a long (14) or short (15) direction vane;
said tubular cavity in fluid communication, in a middle section of the tubular cavity, with a parallel passage (13D) which connects its upper end to the transition tubes (12) of the adjacent module and which lower end is blind, whereas, near its lower end, which may or may not be blind, the cylindrical housing has a transverse outlet opening (13E) directed at the puncture zone.

5. The device of any one of claims 1 to 4, characterized in that the long direction vane (14) is a cylindrical stem provided with couplings for its installation at its upper end, which is positioned in a cylindrical pocket housings (11B) or (13B), with two hydraulic seal gaskets, one of which gaskets is placed prior to the connection of said cylindrical housing with passages (11D) or (13D) and the other gasket placed following said connection and before the transverse outlet openings (11E) or (13E), where the fluid communication between said passages and said outlet openings is interrupted.

6. The device of any one of claims 1 to 4, characterized in that the short direction vane (15) is a cylindrical stem provided with couplings for its installation at its upper end, which is positioned in the cylindrical pocket housings (11B) or (13B), prior to the connection of said cylindrical housing with the passages (11D) or (13D) without interrupting the fluid communication between said passages and said outlet opening.