Abstract:
The present invention relates to an inflow control device for controlling the flow of fluid into a tubular deployed in a wellbore comprising coupling between joints of tubulars. The inflow control device is mounted transversely through the coupling in any inflow can control devices the initial condition fluid flow between the exterior and interior of the tubular is prevented. As sufficient pressure is exerted upon the inflow control device from the interior of the tubular the inflow control device is actuated to allow fluid flow between the interior and exterior the tubular. A nozzle in the inflow control device allows fluid to pass at a preset rate. The present invention furthermore relates to a method of assembling an inflow control device according to the invention and to a completion system comprising an inflow control device according to the invention

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/803,600 that was filed on Mar. 20, 2013. 
    
    
     FIELD OF INVENTION 
     Embodiments of the present invention generally relate to methods and apparatuses for a downhole operation. More particularly, the invention relates to methods and apparatuses for controlling the flow of fluids from a hydrocarbon formation into the interior of the tubular. 
     BACKGROUND 
     When producing an oil or gas well is desirable to control the fluid flow into or out of the production tubular, for example, to balance inflow or outflow of fluids along the length of the well. For instance, some horizontal wells have issues with a heel and toe effect, where differences in pressure or the amount of the various fluids that are present at a particular location can lead to premature gas or water breakthrough significantly reducing the production from the reservoir. Inflow control devices have been positioned in the completion string at the heel of the well to stimulate inflow at the toe and balance fluid inflow along the length of the well. In another example, different zones of the formation accessed by the well can produce at different rates. Inflow control devices may be placed in the completion string to reduce production from high producing zones, and thus stimulate production from low or non-producing zones. 
     SUMMARY 
     The concepts described herein encompass various types of inflow control devices. In one embodiment a first hole is bored transversely, or across the sidewall, in a coupling. A second hole is bored from or otherwise formed in the interior of the coupling to intersect the first hole in the sidewall of the coupling. The two holes cooperate to permit fluid communication between the interior of the tubing and annulus. A housing having a throughbore and a piston that is pinned, with the shear pin, in the housing throughbore is inserted into the first hole and locked in place typically by threads on the exterior of the housing that match threads on the interior of the first hole. Typically the piston is sized so that one end may fit into the housing throughbore while the other end is sized to fit into the first hole. Additionally, the end of the piston sized to fit in the first hole has a circumferential groove cut into the periphery so that a seal may be placed in the circumferential groove thereby sealing the piston against fluid leaking past the piston towards the exterior of the tubular. Finally a biasing device, such as a spring, is added to bias the piston away from the housing. 
     In order to actuate the inflow control device described above, fluid pressure inside the tubular is increased in order to apply force to the end of the piston thereby forcing the piston further into the housing throughbore. The fluid pressure inside the tubular may be increased as many times as is required as long as the pressure necessary to shear the shear pin and to overcome the spring bias is not surpassed. However when sufficient pressure is applied to the interior of the tubular and the piston is forced to move further into the housing throughbore the shear pin is sheared releasing the piston toe move relatively freely in the housing throughbore. When the pressure inside of the tubular is released the bias device pulls the piston out of the housing throughbore allowing fluid access between the interior of the tubular and the exterior the tubular although the nozzle in the housing limits the amount of fluid that may pass. 
     In another embodiment of an inflow control device a first hole is formed transversely, or across the sidewall, in a coupling. A second hole is formed from the interior of the coupling to intersect the first hole in the sidewall of the coupling so that the two holes together permit fluid communication between the interior of the tubing and annulus. A housing having a throughbore is inserted into the first hole and locked in place typically by threads on the exterior of the housing that match threads on the interior of the first hole. In many instances a circumferential groove is cut in the housing allowing a seal to be inserted into the housing to seal the potential fluid pathway between the exterior of the housing and the first hole although in some instances the groove may be cut into the sidewall of the first hole. Typically the housing includes a rupture disc on the end of the housing towards the interior of the tubular. The rupture disc may be incorporated into the housing or may be a separate assembly as long as the rupture disc prevents fluid flow into the interior of the housing from the interior of the tubular when the fluid pressure in the interior of the tubular is below a specified pressure. The throughbore of the housing also incorporates a series of shoulders where the shoulders are arranged to support parts of the inflow control device placed on the shoulder from the exterior of the tubular, in other words the shoulders provide support for parts of the inflow control device to resist pressure applied from the exterior or annular region of the tubular. The first shoulder or the shoulder furthest away from the exterior of the tubing retains and supports an erodible or frangible support disc. The erodible support disc may have holes, aligned with the throughbore, that pass through the erodible support disk to allow fluid to pass through after the rupture disc ruptures. The second shoulder, slightly closer to the exterior of the tubing than the first shoulder supports a sealing disk. The sealing disk is supported by both the erodible support disc and the second shoulder. The sealing disk prevents fluid, including high-pressure fluid, from moving through the inflow control device from the exterior of the tubing towards the interior of the tubing. A nozzle is inserted into the through bore usually slightly closer to the exterior of the tubing the sealing disk to allow the nozzle to be easily replaced. In some instances the nozzle may be part of the through bore. 
     In order to actuate the inflow control device described above, fluid pressure inside the tubular is increased in order to rupture the rupture disc. The fluid from inside the tubular then flows past the rupture disc and to the erodible support disc. The fluid then flows through the holes in the erodible support disc allowing the fluid to apply force to the sealing disk. Typically the sealing disk is not supported, or maybe lightly supported, towards the exterior of the tubular allowing the fluid from the interior of the tubular to push the sealing disk out of the inflow control device. After the rupture disk and the sealing disk have been removed by fluid under pressure from the interior of the tubular fluid communication is established between the exterior to the interior of the tubular. Over time, as fluid passes through the holes in the erodible support disc, the erodible support disc dissolves or is eroded away allowing fluid to flow between the interior of the tubular and the exterior of the tubular at a flow rate determined by the nozzle in the throughbore. 
     In another embodiment of an inflow control device a first hole is formed transversely, or across the sidewall, in a coupling. A second hole is formed from the interior of the coupling to intersect the first hole in the sidewall of the coupling so that the two holes together permit fluid communication between the interior of the tubing and annulus. A housing having a throughbore is inserted into the first hole and locked in place, typically by threads, on the exterior of the housing that match threads on the interior of the first hole. In many instances a circumferential groove is cut in the housing or first hole sidewall to allow a seal to be inserted into the groove to seal the fluid pathway between the exterior of the housing and the first hole. A piston that is typically pinned with a shear pin in the housing throughbore is inserted into the first hole. Typically the piston is sized so that one end may fit into the housing throughbore while the other end is sized to fit into the first hole. Additionally the end of the piston sized to fit in the first hole may have a circumferential groove cut into the periphery so that a seal may be added sealing the piston into the first hole. An explosive charge including a primer is located in the housing throughbore on the side of the piston towards the annulus of the tubular. A charge seal is then placed in the housing throughbore on the side of the explosive charge towards the annulus of the tubular. The charge seal prevents fluid, including high-pressure fluid, from moving through the inflow control device from the exterior of the tubing towards the interior of the tubing. A nozzle may be included in the housing throughbore. In some instances the nozzle may be part of the through bore. 
     In order to actuate the inflow control device described above, fluid pressure inside the tubular is increased to a level that causes the piston to shear the shear pin thereby allowing the piston to move further into the housing throughbore. As the piston moves further into the housing throughbore the piston strikes or otherwise causes the primer to the fire causing the explosive charge to detonate. The force of the explosive charge detonating removes the charge seal and forces the piston out of the through bore. Fluid communication is thereby established between the exterior to the interior of the tubular. Overtime, as fluid passes through the holes in the erodible support disc, the erodible support disc dissolves or is eroded away allowing fluid to flow between the interior of the tubular and the exterior of the tubular at a flow rate determined by the nozzle in the through bore. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  depicts a tubing string having multiple couplings were each coupling incorporates an inflow control device. 
         FIG. 2  depicts a coupling having a tubular threaded into each end thereof where the coupling includes an inflow control device. 
         FIG. 3  depicts an end view of the coupling including an inflow control device. 
         FIG. 4  depicts a portion of a coupling with a closeup view of an inflow control device prior to actuation. 
         FIG. 5  depicts a portion of a coupling with a closeup view of an inflow control device where pressure is being exerted upon the piston from the interior of the tubular thereby shearing the shear pin. 
         FIG. 6  depicts a portion of a coupling with a closeup view of an inflow control device after pressure from the interior of the tubular has been relieved allowing the bias device to remove the piston from the housing throughbore. 
         FIG. 7  depicts a portion of a coupling with a closeup view of an alternative inflow control device prior to actuation. 
         FIG. 8  depicts a portion of a coupling with a closeup view of an alternative inflow control device after pressure has been exerted upon the rupture disk from the interior of the tubular and the same fluid has passed through the holes in the support disc to remove the sealing disk from the through bore of the housing. 
         FIG. 9  depicts a portion of a coupling with a closeup view of another alternative inflow control device prior to actuation. 
         FIG. 10  depicts a portion of a coupling with a closeup view of another alternative inflow control device after sufficient pressure has been applied from the interior of the tubing to shear the shear pin and allow the piston to contact the primer. 
         FIG. 11  depicts a portion of a coupling with a closeup view of another alternative inflow control device after the explosive charges detonated thereby removing the charge seal and the piston from the housing through bore. 
     
    
    
     DETAILED DESCRIPTION 
     As depicted in  FIG. 1  an inflow control device  118  has been designed for use with a liner string completion in a deviated or horizontal application. Individual tubular joints of liner are joined using a threaded coupling  112 . A first hole  116  has been drilled into the wall of the coupling  112  which houses the inflow control device  118 . 
     As depicted in  FIGS. 2 and 3  a second hole  120  is drilled through the wall of the coupling  112  which intersects the first hole  116  such that it permits communication of fluids between the tubing and annulus of the liner string. In certain instances the first hole may be drilled in to the coupling such that the first hole allows for fluid communication between the exterior of the coupling to the interior of the coupling through the first hole. In one embodiment an inflow control device is placed into the hole to moderate the fluid flow through the hole between the interior of the coupling and the exterior of the coupling. 
     The inflow control device  118  is placed inside the first hole  116 , and once installed, creates a pressure barrier between the tubing  110  and coupling  112  assembly and the annular area  113  exterior of the tubing  110  and coupling  112  assembly while still sensing pressure from both the tubing interior  115  and the annular area  113 . The inflow control device  118  typically is capable of withstanding cyclical, hydrostatic annular area pressure or the application of high pressure in the tubing interior  115 . Typically such pressure cycles may be 3000 psi hydrostatic annular area  113  pressure or 3000 psi tubing interior  115  pressure for five cycles. The application of pressure in excess of the normally expected pressure should cause the inflow control device  118  to actuate, allowing at least some fluid communication between the tubing interior  115  and the annular area  113 . Typically such excess pressure may be about 3,700 psi-5,000 psi before the tubing pressure causes the device to actuate, allowing fluid communication between tubing and annulus. Once actuated the inflow control device  118  creates a user-selectable orifice for flow restriction, which can be changed at any time prior to run-in. Typically the user selectable orifice may be between 4-6 millimeters. 
     Typically the coupling  112  is a standard casing coupling. The first hole is typically formed by drilling, milling, casting or any other means known in the art. The typical coupling  112  shown in  FIG. 2  has a first box end  122 , a second box end  124 , and a center  121 . A first tubing  110  has a first pin end  126  that is threadedly attached to the first box end  122  of the coupling  112 . A second tubing  130  has a second pin end  132  that is threadedly attached to the second box end  124  of the coupling  112 . Between the first box end  122  and the second box end  124  the coupling  112  typically has a region  134  that has about the same wall thickness D 1  as the wall thickness D 2  as the tubings  110  and  130 . The first hole  112  is typically formed in the coupling  112  in the region  134 . 
       FIGS. 4-6  depict an embodiment of an inflow control device  118  in coupling  112 . A first hole  116  is formed in the region  134  of the coupling  112 . In certain instances the first hole  116  may be cut full bore or partial bore through the coupling  112  with a plug inserted from the opposing end to plug at least a portion of the bore and in many instances may provide an anchor for the spring  314 , such as a second female thread  218  or a ferrule. The first hole  116  typically consists of a first female thread  210 , an angled shoulder  212 , a hone bore  214 , a hone relief bore  216 , and a second female thread  218 . A second hole  120  has been cut through the wall of the coupling  112  such that it intersects the first hole  116  to permit fluid communication between the tubing interior  115  and annular area  113 . 
     A piston  310  with a seal  312  is placed in the hone bore  214  of the first hole  116  such that it creates a pressure barrier between tubing interior  115  and annular area  113 . The front face  330  of piston  310  has a bore  332  having a female thread. A spring  314  may be threadedly attached to the bore  332  of the piston  310 . In the first state, depicted in  FIG. 4 , the spring  314  is extended and exerts an axial force on the piston  310  as depicted by arrow  334 . There is a radial hole  316  through the piston  310 . Towards the annular area  113  adjacent to piston  310 , a shear sleeve  318  is mated against the angled shoulder  212 . The shear sleeve  318  has a radial hole  320  through its wall which aligns with the radial hole  316  in the piston  310 . A shear pin  322  is placed through the mating holes  316  and  320 . Towards the annular area  113  adjacent to shear sleeve  318 , a flow nozzle  324  with a male thread is threaded into the female thread  210 . The flow nozzle  324  may have an internal diameter sized to restrict fluid flow between the tubing interior  115  and annular area  113  of the well to a desired rate. This internal diameter can be adjusted based on the requirements of a specific well environment. An erodible and/or dissolvable metering disk  326  may reside in the internal diameter of the flow nozzle  324 . The metering disk  326  may have one or more holes through it to permit fluid communication between the tubing interior  115  and annular area  113 . The flow nozzle  324  is threaded into the first hole  116  such that it is adjacent to shear sleeve  316 . The flow nozzle  324  locks all internal parts in place within the coupling  112 . Various sizes of flow nozzles  324  can be used, and can be interchanged at any time without affecting operation of the device  118 , without requiring disassembly of the device  118 , and without the need for specialized tooling. 
     Pressure applied to the annular area  113  of the well acts on the piston  310  creating an axial force in the direction of arrow  334  on piston  310  which tends to shear the shear pin  320 . The shear pin  320  is sized such that it can withstand constant applied pressure from the annular area  113  without actuating the inflow control device  118 . Typically the shear pin is sized such that it can withstand about 3,000 psi constant applied pressure from the annular area  113  without actuating the inflow control device  118 . 
       FIG. 5  depicts an intermediate position of the inflow control device  118  where pressure applied to the tubing interior  115  acts on the front face  330  of piston  310 . This pressure creates an axial force on the piston  310  in the direction of arrow  336  which tends to shear the shear pin  320 . The shear pin  320  is sized such that it can withstand about 3,000 psi applied pressure from the tubing interior  115  five times without being sheared. However, when higher pressure, typically between 3,700 and 5,000 psi, is applied to the tubing, the shear pin  320  shears, allowing the piston  310  to travel outward while maintaining a seal in its hone bore  214 . The piston  310  travels outward until it shoulders against the shear sleeve  316 . In this condition, the inflow control device  118  continues to maintain the seal between the tubing interior  115  and the annular area  113  as long as tubing pressure is maintained. Decreasing pressure in the tubing interior  115  causes a decreasing outward force in the direction of arrow  336  on the piston  310 , allowing the spring  314  to pull, as indicated by arrow  337 , the piston  310  away from the annular area  115  until the seal  312  is past the end of the hone bore  214  and is inside the hone relief bore  216 . At this point, fluid communication is achieved between the tubing interior  115  and annular area  113 . 
     As depicted in  FIG. 5  the spring  314  continues to pull the piston  310  inward until the spring reaches its relaxed state. At this point, the piston  310  is far enough away from the annular area  113  that full flow capacity is achieved between the tubing interior  115  and annular area  113 , with the flow nozzle  324  acting as the primary restriction in the system. Once fluid begins to flow across the metering disk  326 , the metering disk  326  may begin to erode and/or dissolve. Because of the flow restriction created by the small holes  338  in the metering disk  326 , prior to the metering disk  326  eroding or dissolving away, it may be possible to build pressure inside the tubing even if a number of devices  118  in the completion string have opened and are communicating fluid between the tubing interior  115  and the and annular area  113 . Thereby allowing the operator to develop sufficient pressure in the tubing interior  115  to ensure that all inflow control devices  118  in the well are actuated prior to full flow being established between the tubing interior  115  and annular area  113 . Typically the metering disks  326  each erode and/or dissolve over a short period of time as a result of production through the completion string, leaving the flow nozzles  324  as the primary flow restrictions in the completion string. 
       FIGS. 7 and 8  depict an alternate embodiment of an inflow control device  417 . A port  410  placed in the wall of the coupling  112  consists of a hone bore  412 , a female thread  444 , an angled sealing shoulder  416 , and a hole for fluid communication  418 . A slot  420  has been cut through the wall of the coupling  112  such that it intersects the port  410  to permit fluid communication between the tubing interior  440  and annular area  442 . 
     A housing  422  with a seal  424  and a male thread  446  is inserted into the port  410  in the coupling  112  such that it threads into a female thread  444  in the coupling  112 , and its seal  420  resides in the hone bore  412 . The housing  422  is threaded in and tightened until a metal-to-metal pressure seal is achieved between an angled nose of the housing  426  and the angled sealing shoulder  416 . The housing  422  has an integral rupture device  428 . A small erodible and/or dissolvable metering disk  430  has been press-fit into the end of the housing  422  nearest to the annular area  442 . The metering disk  430  may have one or more holes such as holes  450 ,  452 , and  454  through its thickness to permit fluid communication between the tubing interior  440  and annular area  442 . A sealing disk  432  is placed inside the housing  410  adjacent to the metering disk  430 . The sealing disk  432 , housing  422 , and seal  424 , isolate pressure in the annular area  442  from the rupture device  428  and metering disk  430 . Behind the sealing disk  432 , a flow nozzle  434  with a male thread is threaded into the female thread  414  inside the housing  422 . The flow nozzle  434  is tightened into the housing  422  such that the flow nozzle  434  creates a seal between itself and the sealing disk  432 , as well as between the sealing disk  432  and a shoulder  436  inside the housing  422 . The flow nozzle  434  has a specific internal diameter sized to restrict fluid flow between the tubing interior  440  and annular area  442  of the well to a desired rate. This internal diameter can be adjusted based on the requirements of a specific well environment. Various sizes of flow nozzles  434  can be used, and can be interchanged at any time without affecting operation of the device  118  and typically without the need for specialized tooling. 
     Pressure in the annular area  442  typically does not affect the inflow control device  118 , as the rupture device  428  does not sense pressure from the annular area  442 . The sealing disk  432  is supported by the metering disk  430 , which allows the sealing disk  432  to seal pressure in the annular area  442  without yielding. Therefore, pressure can be applied to the annular area  442  as needed without actuating the inflow control device  118 . 
     Pressure applied to the tubing interior  440  acts on the side of the rupture device  428  that is exposed to the tubing interior  440 . The rupture device  428  is typically sized such that a designated pressure may be applied to the tubing over many cycles without affecting the rupture disk  428 . However, when a pressure in excess of the designated pressure is applied, the rupture disk  428  ruptures in a controlled and predictable manner. 
     As depicted in  FIG. 8 , once the pressure limit of the rupture disk  428  is reached, the rupture disk  428  ruptures, allowing fluid to flow through the metering disk  430 . The fluid communication holes  450 ,  452 , and  454  in the metering disk  430  permit fluid from the tubing interior  440  to apply pressure to the sealing disk  432 , which is not supported towards the annular area  442 . Therefore the sealing disk  432  breaks or otherwise be removed as pressure is applied from the tubing interior  442  establishing fluid communication between the tubing interior  440  and annular area  442 . 
     Typically the metering disk  430  is made of an erodible and/or dissolvable material such as polyglycolic acid. Fluid flow in either direction across the metering disk  430  tends to erode and/or dissolve the metering disk  430  at a predictable rate. Prior to the metering disk  430  eroding and/or dissolving, pressure can still be built up in the tubing interior  440  because of the temporary flow restriction created by the small holes  450 ,  452 , and  454  in the metering disk  430 , allowing the operator to develop sufficient pressure in the tubing interior  440  to ensure that all inflow control devices  118  in the completion string may be actuated prior to full flow being established between the tubing and annulus. The metering disks  430  then erode over a time as a result of production through the completion string, leaving the flow nozzle  434  as the primary flow restriction in the completion string. 
     Typically the rupture disk  428  is sized such that 3,000 psi may be applied to the tubing interior  440  about five times. The rupture disk  428  ruptures in a controlled and predictable manner when between 3,700 and 5,000 psi is applied to the tubing interior  440 . 
     An alternate embodiment is depicted in  FIGS. 9-11 . A port  510  formed in the wall of the coupling  112  consists of a female thread  512 , a bore  514  with a seal groove  516 , an angled shoulder  518 , and a hone bore  520 . A slot  522  has been cut through the wall of the coupling  112  such that it intersects the port  510  to permit fluid communication between the tubing interior  550  and annular area  552 . 
     A housing  524  with a male thread  513  is threaded into the female thread  512  in the port  510  until the angled shoulder  526  on the housing  524  mates against the angled shoulder  518 . A seal is created between the outer diameter of the housing  524  and a housing seal  528  that resides in the seal groove  516 . A first radial hole  530  has been drilled through the housing  524 . A piston  532  with a piston seal  534  is located inside the hone bore  520 . A second radial hole  536  has been drilled through the end of the piston  532 . The piston  532  is located such that the second radial hole  536  is aligned with the first radial hole  530 . A shear pin  538  is inserted through first radial hole  530  and second radial hole  536 , locking the piston  532  and housing  524  together. An explosive charge  540 , such as a shaped charge, with an integral primer  542  is inside the housing  524  such that the primer  542  faces the piston  532 . A charge seal  544  is located behind the explosive charge  540 . The charge seal  544  forms a seal inside the inner diameter of the housing  524 . The piston  532  has a small protrusion  546  on its outer face that is designed to engage the primer  542  on the explosive charge  540 . 
     Pressure applied to the annular area  552  of the well does not affect the inflow control device, as the housing seal  528  and charge seal  544  create pressure barriers inside the port  510 . Therefore, pressure can be applied to the annular area  552  without actuating the inflow control device. 
     Pressure applied to the tubing interior  550  of the well acts upon the piston  532 . This pressure creates a force on the piston  532 , in the direction of arrow  554 , which tends to shear the shear pin  538 . The shear pin  538  is sized such that it can withstand pressure applied from the tubing interior  550  over several cycles without being sheared. Typically the shear pin  538  is sized such that it can withstand about 3,000 psi applied pressure from the tubing interior  550  about five times without shearing. However, when higher pressure is applied to the tubing, the shear pin  538  shears, allowing the piston  532  to travel outward while maintaining a seal in the hone bore  520 . Typically, the shear pin  538  shears when pressure between 3,700 and 5,000 psi is applied to the tubing interior  550 . The piston  532  travels outward until the protrusion  546  contacts the primer  542  on the explosive charge  540 . When the protrusion  546  contacts the primer  542 , it ignites the explosive charge  540 , which applies pressure to create a hole through the piston  532 , as well as eliminate the charge seal  544 . At this point, fluid communication between the tubing an annulus is achieved, with the inner diameter of the housing  524  functioning as the primary flow restriction in the completion string. 
     Bottom, lower, or downward denotes the end of the well or device away from the surface, including movement away from the surface. Top, upwards, raised, or higher denotes the end of the well or the device towards the surface, including movement towards the surface. While the embodiments are described with reference to various implementations and exploitations, it is understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. 
     Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.