Abstract:
A modular screen system allows connection of screens using couplings that connect the annular space in each module between the screen material and the base pipe. A series of connected screens and couplings feed into a single valve to control the flow through many screens. The valve is preferably located in a coupling and the passages through the coupling or the screen can also accommodate instrumentation to detect, store or transmit well data or flows through the various screen modules.

Description:
FIELD OF THE INVENTION 
     The field of the invention is screen assemblies that span multiple zones and more particularly modular screen components that can be assembled with couplings where the couplings can control flow through screens in a given zone. 
     BACKGROUND OF THE INVENTION 
     In completions that span multiple zones, an array of screens is frequently positioned in each of the zones. The zones are typically isolated with packers and are individually fractured and gravel packed generally in a downhole to uphole direction. In the past a given zone could be long enough to warrant using multiple screen sections. Typically, each of these screen sections had a base pipe under the screen material and a valve, typically a sliding sleeve, associated with each screen section. The annular space between the screen material and the base pipe for each screen section was sealed at opposed ends on a given screen section and the only access into the base pipe for flow of production to the surface was the sliding sleeve valve in each of the sections. 
     This configuration required multiple sliding sleeve valves that had to be operated and created issues of flow distribution within a given zone. This lead to the concept of connecting the annular spaces between adjacent screens through the use of ported couplings. This, in essence, made the various standalone screens function more akin to a single screen. Several US Patents illustrate the jumper path between the annular flow areas between the screen and its respective base pipe, and they are U.S. Pat. Nos. 6,405,800 and 7,048,061. U.S. Pat. No. 6,752,207 shows a way to hook together shunt tubes outside of screen sections through couplings. U.S. Pat. Nos. 6,464,006 and 5,865,251 show gravel packing systems that use screens with sliding sleeves that can close them off, such as when a wash pipe with a shifting tool is pulled out of the screen assembly. U.S. Pat. No. 7,451,816 uses base pipe openings in screens that can be covered as an aide to gravel deposition in a surrounding annulus. 
     Despite the various designs that connected annular spaces in screens through jumper lines and couplings between the screen sections, the base pipes continued to hold the sliding sleeves so that there was still as many sliding sleeves to operate as before to fully open a zone. The other lingering issue of the prior designs with the location of the sliding sleeves inside the base pipe flow bore and directly under the screen assembly that covered the base pipe was that the resulting flow area or drift dimension of the screen section was diminished which limited the size of tools that could get through a given screen as well as created flow constrictions that could limit production or require the use of artificial lift techniques that consume additional power and create other costs for procurement and installation. 
     The present invention addresses these issues and others by placing the access valves in the couplings where there is generally more room to locate the valve structure because the outside dimension of the coupling does not have the overlying screen structure on it. Additionally a single valve can connect some to all of the screens in a given zone so as to make access to entire zone for flow or for isolation go that much faster. The equipment cost is reduced as well as the risk of a malfunction. The flow is not constricted with the valve assembly located in a coupling. The passages among the screen sections that encompass the couplings can also be the location for a variety of instruments that can sense well conditions and flow through the screen sections to name a few examples. These and other aspects of the present invention will become more apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while understanding that the full scope of the invention is determined by the appended claims. 
     SUMMARY OF THE INVENTION 
     A modular screen system allows connection of screens using couplings that connect the annular space in each module between the screen material and the base pipe. A series of connected screens and couplings feed into a single valve to control the flow through many screens. The valve is preferably located in a coupling and the passages through the coupling or the screen can also accommodate instrumentation to detect, store or transmit well data or flows through the various screen modules. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a section view of a screen module; 
         FIG. 2  is the section view through line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a perspective view of the screen module of  FIG. 1 ; 
         FIG. 4  is a section view of a coupling without a valve in it; 
         FIG. 5  is a section view along lines  5 - 5  of  FIG. 4 ; 
         FIG. 6  is a section view of a coupling with a sliding sleeve valve in it shown in the open position; 
         FIG. 7  is a section through line  7 - 7  of  FIG. 6 ; 
         FIGS. 8   a - 8   b  are a section through an assembly of screens showing both kinds of couplings with one sliding sleeve in the closed position and another in the open position; 
         FIG. 9  is a section through a coupling showing schematically an instrument in the flow passage of the coupling that connects the annular space in adjacent screens. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A screen module  10  is shown in  FIGS. 1-3 . It has a solid base pipe  12  that defines a through passage  14 . A series of parallel ribs  16  retain a wire wrap screen  18  that overlays the ribs  16  creating parallel passages  20  that go under the screen  18 . While one style of screen  18  is illustrated, those skilled in the art will appreciate that other types of screens can be used depending on the requirements of the specific application. For clarity, only one end ring  22  is illustrated that is welded at  24  to the right of the screen  18 .  FIGS. 8   a - 8   b  show a complete screen module  10  illustrating the symmetry of the structure by using end ring  26  welded at  28  to screen  18 .  FIG. 2  illustrates a section view through the end ring  22  showing passages  30  which preferably are in alignment with passages  20  between the rib wires  16 . Passages  30  in the aggregate can have different cross sectional flow areas in different modules to serve as inflow control devices for flow balancing among modules  10 . Alternatively, all modules can be identical and inflow control for flow balancing can be accomplished in other ways. 
     The end ring  22  has an end  32  against which abuts housing  34  of a coupling  36 . The same occurs at end ring  26  but with a different coupling  36 . Referring now to  FIGS. 4 and 5 , the coupling  36  has a body  38  that has threads  40  and  42  at opposed ends. The housing  34  has a series of passages  44  that are in flow communication with passages  30  through an annular space  46  formed when housing  34  is butted to end  32  as thread  40  is made up to thread  48  of screen module  10  shown in  FIG. 1 . The flow area in the aggregate between passages  30  and  44  can be in different proportions at screen modules  10  so that the flow area differences can serve as a form of inflow control device to balance flow among modules  10  in a given zone. 
     Another coupling type  50  is shown in  FIGS. 6 and 7 . It has a housing  52  and threads  54  and  56  at opposed ends. An outer housing  60  has a series of passages  62  that extend from end  64  to end  66 . Passages  62  can also serve as inflow control devices for flow balancing among screen modules  10  in a given zone. A sliding sleeve  68  is positioned between shoulders  70  and  72  to define opposed travel limits. A series of openings  74  on the sliding sleeve  68  are shown aligned with openings  76  in housing  52 . In this position there is flow possible between passage  62  and the main bore  78  in housing  52 . Seals  80  and  82  are spaced far enough apart so that the ports  76  can be closed when the sliding sleeve  68  shifts so that seals  80  and  82  straddle the ports  76 . The closed position is shown in  FIG. 8   a . Note that, as shown in  FIG. 6 , the drift diameter  84  is the minimum diameter through the housing  52  and that such diameter is not reduced by the inside diameter  86  of the sleeve  68 . 
     While the valve  68  is illustrated as a sliding sleeve other variations are envisioned. The sleeve  68  can rotate to open and close ports  76 . Alternatively, pressure or temperature or other types of plugs in openings  76  can be used that, for example, can be responsive to cycles of applied and removed pressure to go between open and closed positions such as in conjunction with a j-slot mechanism. Alternatively, the valve member can be responsive to production of certain fluids like water or gas to go to the closed position. 
       FIGS. 8   a - 8   b  show an overall system with the couplings  50  that incorporate sliding sleeves  68  at opposed ends of  FIG. 8 . In  FIG. 8   a  the ports  76  are closed as seals  80  and  82  mounted to sliding sleeve  68  straddle opening  76 . In  FIG. 8   b  openings  74  and  76  are aligned so that flow represented by arrows  88  can enter the main bore  78  to get to the surface (not shown). Note that in  FIGS. 8   a - 8   b  there are three screen modules  10  of the type shown in  FIGS. 1-3  and they are labeled in  FIGS. 8   a - 8   b  as  90 ,  92  and  94 . Flow from the formation, represented by arrows  96  bypasses closed port  76  and can first enter screen  90 . Arrows  96  and  98  illustrate the flow that started in from the annular space  100  and passed through screen  90 . Annular space  100  at this time is preferably full of gravel. Note the flow indicated by arrow  98  is toward the open coupling  50  that has a sliding sleeve valve  68  in  FIG. 8   b . Inflow from screens  92  and  94  mixes with the incoming flow through screen  90  and all the flow winds up at ports  76  in  FIG. 8   b  as there is a dead end  102  just beyond openings  76  in  FIG. 8   b . In the illustrated example, a single coupling  50  in  FIG. 8   b  controls incoming flow from three screens  90 ,  92  and  94 . Those skilled in the art will appreciate that any number of screens in a given isolated zone can be tied together depending on the formation pressure, the size of the flow passages between the screens, the length of a zone and the distance to the surface as well as the tubing size for the production string to the surface to mention a few of the variables. However, the illustrated system in  FIGS. 8   a - 8   b  allow economy of valves as a single valve can control an entire zone of inflow that may have many modules of screen sections in it. Further, the drift  84  is not reduced or reduced less than it would have been had the sliding sleeves been aligned with a screen module  10 . Because the sliding sleeves  68  are in a coupling  50  rather than in a screen module  10  the negative impact on drift is less severe or non-existent. Note also that the couplings  36  or  50  do not have any welds. This is noteworthy because such couplings are made up in the field where welding equipment and personnel who can weld may not be present. While the screen modules have welds  24  and  28  to secure the end rings  22  and  26  to the screen material  18  such welds are made in the shop where the screen modules  10  are fabricated under controlled conditions. In the field, tongs are used by rig personnel to thread the screen modules  10  together using couplings  36  or  50 . Note that the outer housings  34  or  60  preferably abut at their ends to end rings on the screen modules  10 . A leak tight connection is not critical as long as any gravel in the annular space  100  cannot infiltrate and bypass screening at screens such as  90 ,  92  and  94 . 
     A single zone can have as few as one screen section  10  connected by a valved coupling  50  or many screen sections  10  connected by un-valved coupling  36  with one or more valved couplings  50  anywhere in the zone or either at one of the ends or anywhere in between. The objective is to link the screens  10  and produce them all from a given zone through at least one valved coupling such as  50 . The zones can be isolated with a variety of packers either on opposed end or on one end if the zone goes to the hole bottom. 
       FIG. 9  shows a screen such as  90  with an associated end ring  22  that defines internal passages  30 . Schematically illustrated as  104  is one of many instruments that can be associated with the passage  30  for a variety of purposes such as measuring or controlling flow, pH, temperature, properties of the produced fluids such as density, viscosity or pressure to name a few. It can also be a flow control device that can be varied in conjunction with sliding sleeve position or independently of it and based on well fluid properties. This data can be logged or transmitted to the surface in real time through cables, conduits or even acoustically through the well fluids or the production sting itself. Instruments can be combined with inflow control devices for flow balancing among screen sections or combined with control devices for chemical injection stimulation. Power can be supplied to such sensors or instruments or they can be powered with locally mounted batteries. Power could be generated with some property of the flowing fluid. Other passage mounted devices can be oil and water or oil and gas separators or such passages can be incorporated into the gravel packing or fracturing operations for taking returns when depositing gravel outside screens or for delivering fracture fluids through the screens. Item  104  could be part of the base pipe or a separate module that connects the screen via a threaded connection. A centralizer  105  could be included as part or the screen module, the coupling, or as a module between them. 
     The sliding sleeves  68  can be operated with shifting tools on work strings, hydraulic control lines or electric motors to name a few variations. Flow in the passages that lead to openings  76  can be in one direction or two directions. Such passages can be used as return passages during gravel deposition or for fracturing. 
     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.