Abstract:
A method for controlling commingling of flows from multiple zones. The method includes physically containing flows from different zones to individual concentric flow channels in a nested tubular arrangement and selectively commingling two or more of the flows by setting at least one valve associated with each flow channel to a closed position or one of an infinite number of flow capable positions.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a continuation patent application of U.S. patent application Ser. No. 10/420,303, filed Apr. 22, 2003, which claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/378,208 filed May 6, 2002, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND  
       [0002]     In the beginnings of drilling for oil and other hydrocarbon resources, a relatively vertical well was drilled into the earth&#39;s surface and whatever pockets of fluid were encountered would be produced at the surface. This includes different phases of desired hydrocarbons, water, etc. Many times only a single component of the formation reserve is desired to be produced and it is costly and time consuming to separate the produced fluids into the constituent components thereof once they have been intermingled. In order to alleviate the need for separation, the art has learned to separate zones of production into smaller sections. This can be done in a number of ways including by gravel packing and packing off different sections. After a gravel packing operation, fluids can only enter the wellbore through a holed base pipe in a particular section where those fluids were produced from the formation. One of the problems associated with controlling these individual zones is that the gravel pack (or other downhole arrangement) tends to restrict the I.D. of the tubing string making it difficult to install a valve at that location. Installation of valves uphole of the gravel pack has been limited to two for a significant period of time as there has been no way to control more zones through valves located uphole of the gravel pack.  
       SUMMARY  
       [0003]     Disclosed here is a production control system having a series of nested tubular members including at least one axial flow channel and at least two annular flow channels.  
         [0004]     At least one valve configured and positioned to control flow from each flow channel is provided.  
         [0005]     Further disclosed herein is a production apparatus having a series of nested tubulars connected to one another such that at least an axial flow channel and at least two annular flow channels are formed.  
         [0006]     A valve is associated with each of the flow channels and is configured and positioned to independently control flow from each of the flow channels.  
         [0007]     Further disclosed herein is a method for controlling commingling of flows from multiple zones. The method includes physically containing flows from different zones to individual concentric flow channels in a nested tubular arrangement and selectively commingling one or more of the flows by setting at least one valve associated with each flow channel to a closed position one of an infinite number of flow capable positions. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     Referring now to the drawings wherein like elements are numbered alike in the several Figures  
         [0009]      FIG. 1  is a schematic cross sectional view of a multiple zone downhole intelligent flow control valve system. 
     
    
     DETAILED DESCRIPTION  
       [0010]     A multiple zone downhole intelligent flow control valve system is illustrated generally at  10  in  FIG. 1 . One of ordinary skill in the art will recognize the appearance of a well system wherein a section of the casing is illustrated at  12 . Illustrated downhole of the casing section are three distinct production zones  14 ,  16  and  18 , respectively. Each zone is schematically illustrated. The individual zones are delineated with packers  20 ,  22  and  24  as well as discrete screen sections  26 ,  28  and  30 , although it should be understood that a single extended screen section could replace the individual screen sections without changing the function of the device. Extending downhole through the screen sections as identified are two pipes  32  and  34  of different lengths. It will be noted that pipe  32  is smaller than pipe  34  in diameter and is the pipe that extends farther downhole than pipe  34 . Pipe  32  includes an annular packer  36  (or seal) which is nested with packer  20 . Pipe  34  ends with a packer  38  (or seal) nested with packer  22 . This, as is illustrated in the drawing, creates three individual flow channels for produced fluid. The fluid from zone  14  flows up the I.D. of pipe  32 . The fluid produced from zone  16  flows through the annular space between pipe  32  and pipe  34  and the fluid produced from zone  18  flows in the annular space defined by pipe  34  and screen section  30 . By so segregating the fluids, each zone of produced fluid enters the cased section  12  of the wellbore separated from each other fluid. Each of these fluids may then be controlled before commingling.  
         [0011]     In order to provide control over all three fluid streams, three separate valves are supplied within the casing segment area  12 . Extending radially outwardly from a seal  40  at pipe  34  is shroud  42 . Shroud  42  is employed to maintain the fluid produced from zone  18  distinct from the fluids produced from zones  16  and  14 . It will be understood that fluids from zones  14  and  16  are separate until and unless mixed in a space defined by shroud  42  by virtue of valves  44  (pipe  34 ) and  46  (pipe  32 ) being open. Within shroud  42 , valve  44  is connected to pipe  34  to regulate fluid therefrom. Pipe  32  extends through the I.D. of valve  44  and up to a valve  46  which controls fluid production from zone  14  and pipe  32 . Each valve  44  and  46 , when open, dumps fluid into shroud  42  and through a holed pipe section (or a valve as desired)  48  (illustrated as holed pipe section). It will be appreciated by those skilled in the art that a plug  49  is installed in pipe  32  immediately uphole of valve  46  to prevent flow of fluid therepast in the lumen of pipe  32 . Were it not for plug  49 , pipe  32  would be contiguous with tubing  50 .  
         [0012]     Fluid flowing through holed pipe section  48  enters production tubing  50  to continue movement uphole. Fluid produced from zone  18  and moving through an annular space defined by shroud  42  at the inside dimension and by casing segment  12  at the outside dimension, moves through valve  52 , if open, to join the fluid produced through holed pipe section  48 . One of ordinary skill in the art will appreciate that valve  44  allows or prevents fluid production from zone  16 , valve  46  allows or prevents production from zone  14  and valve  52  allows or prevents fluid production from zone  18 . This is multizonal control where valve structures are maintained in a casing segment of larger diameter uphole of a gravel pack section. A well operator can therefore selectively close any or all of, and in each permutation thereof, valves  44 ,  46  and  52  to produce any combination of the flow streams including a single stream, a combination of streams or all or none of the streams emanating from the formation. Each of the valves as described above may be actuated hydraulically, pneumatically, electrically, mechanically, by combinations of the foregoing and by combinations including at least one of the foregoing etc. either by surface intervention or by intelligent systems in a downhole environment or uphole. Where intelligent completion systems are employed, at least one sensor would be installed (schematically illustrated as  60 ,  62  and  64 ) in each of the producing zones and in each of the valve sections such that parameters such as pressure, temperature, chemical constitution, water cut, pH, solid content, scale buildup, resistivity, and other parameters can be monitored by surface personnel or at least one controller whether surface or downhole controllers or both, (surface or downhole controller schematically illustrated in operable communication with sensors and valves) in order to appropriately modify the condition of the valves to produce the desired fluid. With appropriately programmed controllers, automatic adjustment of valves is possible and contemplated. It should also be noted that it is intended that each of the valves be variably actuatable such that pressure biases between the zones can be effectuated whereby water breakthrough can be avoided while maintaining production at an optimized level.  
         [0013]     It should now be understood by one of ordinary skill in the relevant art, that the discussion of the apparatus/system above also presents a method for controlling the commingling of well fluids which was heretofore difficult if not impossible in certain well configurations such as multiple zone gravel packs. The method associated with the device described comprises physically containing the flows from different zones in concentrically arranged flow channels as discussed above. The flows are maintained separate until reaching a location where it is possible to valve them such that control is maintained. The method further comprises sensing the fluid parameters somewhere in the flow channel prior to reaching the valve structure in order to allow an operator or a controller to determine that a specific valve should stay closed or should be opened based upon a determination that the fluid being produced is not desired or desired, respectively. The process may be made automatic with appropriate programming for at least one controller.  
         [0014]     While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.