Intelligent Well Control System for Three or More Zones

Abstract

An intelligent well system can service three or more zones that have gravel packed screens. A modular system features a screen and a surface controlled production valve on an internal blank pipe that internally straddles the screen. A gravel exit valve is disposed above the blank pipe and the blank pipe can optionally have a fluid loss control valve. A gravel pack/fracturing assembly can engage each module and close the fluid loss valve and gravel outlet valve on the way out of a module. Optionally the fluid loss valve can be eliminated if the gravel packing and fracturing string has the ability to power the production valve. The modules can be connected by wet connects as can the production string to make the intelligent well system functional from the surface.

Description

FIELD OF THE INVENTION

The field of this invention is intelligent well control from the surface without intervention and more specifically in the context of sand control completions in multiple zones and more specifically targeting three or more zones.

BACKGROUND OF THE INVENTION

Intelligent well control generally involves a way to control and monitor well conditions from the surface without having to intervene in the wellbore. Many applications of such systems have been employed and one is illustrated in FIG. 1. FIG. 1 shows an open hole 10 with packers 12, 14 and 16 isolating zones 18, 20 and 22 respectively with a valve 24, 26 and 28 respectively in each zone. A production packer 30 is disposed in liner 32 with production tubing 34 extending to the surface. Liner 32 is hung to well casing (not shown) at hanger 36. A valve 38 gives access to a fourth zone 40 between packers 30 and 16. Lines 42 which can be hydraulic or electric or fiber optic extend from the surface through the hanger 36 and the packers 12, 14, 16 and 30 to reach the valves 24, 26, 28 and 38 as well as sensors, shown as PDHMS (Permanent Downhole Monitoring System), to determine well conditions such as pressure or temperature. One or more of the zones 18, 20, 22 or 40 can be surface selected for production and the flowing conditions monitored from the surface. If a zone produces water for example it can be cut off from the surface. Other well parameters can be monitored and communication of information can take place in either direction from the producing zones to the surface.

The intelligent well concept has been adapted to gravel pack screen completions as shown in FIG. 2. There a completion assembly 44 includes packers 46, 48 and 50 which define two zones 52 and 54. Screens 56 and 58 align respectively with zones 52 and 54 and are part of the completion assembly 44. The objective of this two zone arrangement is to be able to independently produce the discrete zones. In order to do this a production string 60 is run in and its production packer 62 is set. Valves 64 and 66 are in the string 60 below the packer 62. Valve 66 is encased in a shroud 68 which has a tail section that engages seals 70 and 72 so that flow to valve 66 can only come through screen 56 while the tailpipe in effect seals off an annular space 74 inside screen 58. As indicated by arrow 76, the annular space 74 is in fluid communication with valve 64 to allow discrete access from zone 54 into the string 60. Arrow 78 shows the flow access to valve 66 from zone 52. As part of this intelligent completion, control lines such as those that carry pressurized fluid are run in pairs to opposing sides of an operating piston that in turn moves the valves 64 and 66 to the desired position from the surface without any well intervention. FIG. 3 shows piston cylinders 80 and 82 each respectively having a piston 84 and 86 inside and each responsive to pressure in one of two control lines connected to the respective cylinder. Some of the valves are omitted for clarity but it is clear to those skilled in the art that pressure can be applied to line 88 and if no pressure is applied to lines 90 and 92 at the same time that both pistons 84 and 86 and the respective valves 64 and 66 will be moved to the same position. By applying pressure to both line 88 and one of lines 90 or 92 the valves 64 and 66 will assume opposite positions. A range of positions between open and closed for each valve 64 and 66 is possible at any given time.

While the above layout has worked in the past for two zones, the problem occurs if more than two zones are involved and it is made that much more difficult to have the available space if the completion assembly 44 has a smaller diameter. The problem is a lack of space for nesting enough shrouds that are concentrically disposed. For example, a three zone variation of FIG. 2 would require a second shroud within shroud 68 to isolate another valve (not shown) that would be located below valve 66 and service another zone further downhole past zone 52. There is simply no room in such wells with the FIG. 2 configuration to add additional zones to a completion with gravel packed screens. Another problem is the space-out of multiple seal assemblies with multiple concentric strings while landing the completion.

The method and associated apparatus of the present invention solves this problem. It provides a modular design that allows modules to be stacked in different zones. The modules carry a screen and an internal blank pipe that has the surface operated valve and a gravel exit port. A fluid loss valve can also be provided. A known gravel packing assembly using a crossover and a wash pipe with a sleeve shifter can be employed to gravel pack or fracture in the known manner. The wash pipe when raised to the next zone will close a fluid loss valve in a module and the gravel exit port. Lines can extend between modules and wet connects which are quick couplers connected to each other can be used to operably connect the valves to be operated from the surface from the modules and up to the surface on the outside of the production string. Wet connects are illustrated in U.S. Pat. Nos. 7,228,898; 7,165,892; 6,776,636; 6,755,253; 6,439,932; and 5,294,923. Optionally the gravel packing and fracturing running tool can be equipped with various control lines that tag into a module so that real time conditions during the gravel packing and fracturing can be monitored at the surface. With the use of such a device the production valves that will later be controlled from the surface can also be used for double duty as fluid loss control valves. The screen can have fiber optic inside of it that the running tool can tag into so that strain on the screen can be measured during gravel deposition to gauge the effectiveness of gravel distribution outside the screen. The modules would not need a nesting feature, to eliminate the space problem. Control of a given module can shift from a running tool that engages the module to a surface control from a production string from the surface after the running tool is removed such as when the various zones are fractured and the associated strings are gravel packed.

These and other features of the present invention will be more apparent to those skilled in the art from a review of the detailed description of the preferred embodiment below and the associated drawings, while recognizing that the full scope of the invention is given by the claims that are attached below.

SUMMARY OF THE INVENTION

An intelligent well system can service three or more zones that have gravel packed screens. A modular system features a screen and a surface controlled production valve on an internal blank pipe that internally straddles the screen. A gravel exit valve is disposed above the blank pipe and the blank pipe can optionally have a fluid loss control valve. A gravel pack/fracturing assembly can engage each module and close the fluid loss valve and gravel outlet valve on the way out of a module. Optionally the fluid loss valve can be eliminated if the gravel packing and fracturing string has the ability to power the production valve. The modules can be connected by wet connects as can the production string to make the intelligent well system functional from the surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a prior art 4 zone open hole intelligent well completion system with no screens;

FIG. 2 is a prior art two zone intelligent well completion system with drop in production valves and a shroud to isolate the two zones;

FIG. 3 is a detailed view of the hydraulic system that is surface operated to move the two valves shown in FIG. 2;

FIG. 4 is an illustration of a single stackable module that can be the lower module of an assembly that can do multiple zones in an intelligent well system;

FIG. 5 is a detailed sectional elevation view of the module shown in FIG. 4 that can be elsewhere in a stack of modules and showing the routing of lines through the module.

FIG. 6 is an alternative embodiment to FIG. 5 showing the connections with an axial orientation for connection in the wet connection located near at least one end.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

One module 100 in a screened completion string is illustrated in FIG. 4. The modules 100 can be connected directly to each other across a long producing interval or they can have blank pipe for proper spacing in multiple zones downhole. Each module 100 has at least one screen section 102 and an internal blank pipe 104 that spans the screen 102 and is sealed on opposed ends 106 and 108. There is a gravel exit port with a sliding sleeve to selectively open and close the port 110. The port 110 is offset from the blank pipe 104. A production valve 112 is in blank pipe 104 and the module is pre-piped with control lines 114 better seen in FIG. 5. The hydraulic control lines 114 extend from an upper end 116 to a lower end 118. In one alternative, the radial exit at lower end 118 is between seals 120 and 122. Similarly at opposite end 116 there is a radial exit for the hydraulic lines between seals 124 and 126 of an adjacent blank pipe or other module 128 whose lower end is only shown at the top of FIG. 5. Alternatively, the line pairs such as 119 and 121 can line up axially when mated together as shown in FIG. 6. Other lines for power or signal or information such as fiber optic are schematically represented as 130 and extend from an upper end 132 to a lower end 134. A seal 136 is on the other side of the end of such lines from seal 120 at end 134. At the opposite end 132 the next module or blank pipe 128 has seals 124 and 138 which straddle end 132 to make a sealing connection. Not shown at either end for clarity of the drawing but present is a rotational orientation device so that the connection at opposed ends is properly aligned to provide continuity of pressurized lines, electrical lines or fiber optic lines. Devices that align and connect in a sealing manner a variety of lines in a wet downhole environment are known in the art as wet connects with one 140 being schematically illustrated at the top of FIG. 4 in conjunction with a packer 142 having a seal 144 and slips 146.

Finally, there is an optional fluid loss valve 148 which is typically a sliding sleeve type that can be operated by a wash pipe of a known gravel packing assembly which on the way out of a zone after gravel packing it through the open valve 110 and taking fluid returns through the screen 102 through valve 148 during the gravel pack, will close both valves on the way out of the zone. This closes the screen 102 until that zone is ready to be produced and closes the gravel exit port 110 to return pressure integrity to the assembly which includes multiple modules 100. In sequence and working uphole the zones can be fractured and gravel packed before selective production can begin from one or more zones at a time, as desired. Optionally, the fluid loss valve 148 can be eliminated if the gravel packing assembly shown schematically as 150 has lines 114 and 130 running with it so that a connection C preferably a wet connect can be used to connect to the extension of lines 114 and 130 in the module 100 to operate the production valve 112 from its open position during gravel packing to a closed position before the quick connect is disconnected for fracturing or gravel packing the next zone uphole. This is shown schematically as dashed line 152.

Another option with a gravel packing assembly as shown in FIG. 4 is to place a fiber optic cable 154 against the inside of the screen 102 and have it connected to the surface during gravel packing to give real time screen stress data as an indication of the effectiveness of the gravel distribution around the screen 102. Schematically lines 156 and 158 show the fiber optic cable continuing from opposed ends of the cable 154 against the screen 102 and heading back into connection C of the gravel packing assembly 150.

Those skilled in the art will appreciate that the illustrated equipment and associated method allow for installation of the production valves with the screen with the hydraulic lines in place and disposed for quick connection to the next module or to blank pipe via self aligning quick connections. Ultimately the production string with the associated lines or cables routed into a wet connection can be run downhole and made up with setting down weight to mate two parts of a wet connect to each other and in that way activating the entire completion assembly to operate production valves as needed and to sense well conditions in real time. The lines can be used for other purposes such as chemical injection adjacent any screen. Optionally the fluid loss valves 148 can be eliminated if the fracturing and gravel pack assembly has the lines and cables and the ability to connect to the production valve which can be opened to take returns during the gravel packing and shut if doing a frac job or shut after the particular zone is gravel packed and fractured and the running string assembly 150 is moved to the next zone or out of the wellbore for the production string that wet connects to a topmost packer.

There is now an ability to go beyond the two zones that were the previous limit because the drop in valves with shrouds as illustrated in FIG. 2 had a limit because of space requirement for the shroud. The shrouds are no longer needed using the location of the valve 112 on the blank pipe 104 and preferably offset from the screen to make room for the hydraulic operator for the valve 112. The number of zones is not an issue as compared to the drop in valve design of FIG. 2. The assembly can be further simplified by the elimination of the valve 148 and still have a fluid loss feature by enabling the gravel pack and fracturing assembly to have lines to engage to operate the production valve 112 for double duty. Once for taking returns during gravel packing while being operated from the gravel pack assembly and later in production while being operated by the lines associated with the production string that is wet connected to a topmost packer with all the lines below pre-connected among the modules and any spacers among them. The gravel packing assembly can interact with instrumentation on the screen such as a wound fiber optic cable to measure stress on the screen 102 during a gravel pack and feed that information during the gravel pack to the surface through the gravel packing assembly that has with it the continuation of the fiber optic line down and back from the screen being gravel packed. Other parameters can be measured or chemicals injected through the gravel pack assembly when the auxiliary lines are connected during the frac or the gravel pack.

The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.

Claims

1. An intelligent well completion system for downhole use, comprising:

a tubular string with at least two screens and at least one packer to separate the screens into different zones and a gravel port for each zone;

at least a first and a second axially spaced apart valve assemblies respectively associated with said screens, said valve assemblies operable from the surface of the well to selectively allow flow through said screens without intervention in said string.

2. The system of claim 1, wherein:

a plurality of internal pipes each spanning a respective screen internally of said string and further supporting one of said valve assemblies.

3. The system of claim 2, wherein:

said valve assemblies are actuated from the surface through a control system extending outside said string.

4. The system of claim 3, wherein:

said control system further comprises at least one discrete line to each valve assembly further comprising at least one quick connection.

5. The system of claim 4, wherein:

at least one said line is a hydraulic line that extends through said packer.

6. The system of claim 2, wherein:

said string comprises a gravel port valve and a fluid loss valve associated with each said screen with said fluid loss valve mounted to the internal pipe associated with a respective screen.

7. The system of claim 6, further comprising:

a frac pack assembly further comprising a crossover and a sleeve shifter to selectively operate said gravel port valve and said fluid loss valve to selectively deliver gravel or fluid through said gravel port and to thereafter close off an associated screen with said fluid loss valve.

8. The system of claim 3, further comprising:

at least one sensor adjacent said screen connected to the surface through said control system for transmission of data between said screen and said surface in real time.

9. The system of claim 8, further comprising:

said sensor comprises a fiber optic cable mounted to said screen to detect strain on said screen.

10. The system of claim 3, further comprising:

said string comprises a gravel port valve associated with each said screen;

a frac pack assembly further comprising a crossover and a sleeve shifter to selectively operate said gravel port valve;

said valve assemblies are actuated from the surface through a first control system associated with said frac pack assembly.

11. The system of claim 3, further comprising:

said valve assemblies are additionally controlled through a second control system that runs outside said string, thereby allowing a given valve assembly to be used as a fluid loss valve in conjunction with said frac pack assembly and as a production valve after removal of said frac pack assembly.

12. The system of claim 11, further comprising:

a sensor associated with at least one said screen to transmit to the surface through at least one said control system.

13. The system of claim 12, further comprising:

at least one said control system further comprises a fiber optic cable extending to said screen or a conduit extending to said screen for chemical injection.

14. The system of claim 3, further comprising:

at least three interconnected modules in said string, each featuring a gravel port, one of said screen spanned by an internal pipe, one of said valve assemblies on said internal pipe and a portion of said control system.

15. The system of claim 14, wherein:

at least two modules have end connections on said control system adapted for quick connection of said control system when said modules are assembled.

16. The system of claim 14, wherein:

at least one module has a control system component comprising at least one of a fiber optic cable, a sensor for well conditions, at least one hydraulic line or an open line for chemical injection.

17. The system of claim 14, wherein:

at least two modules have a seal bore at one end and seal at an opposite end for quick connection of adjacent modules.

18. The system of claim 17, wherein:

connecting seals on one module into a seal bore of an adjacent module also connects portions of said control system at the same time.

19. The system of claim 18, wherein:

the components of said control system that connect when modules are pushed together are aligned radially or axially.

20. The system of claim 14, wherein:

said valve assemblies further comprise hydraulically operated sliding sleeves that can be selectively positioned fully open or closed or at least one position in between.