Abstract:
A downhole tool assembly includes a tubular having a flowbore extending along a longitudinal axis of the tubular. An electric actuating mechanism supported by the tubular and distanced from the longitudinal axis of the tubular; and, a valve assembly connected to the tubular and fluidically connected to the flowbore. The valve assembly including: an outer portion having at least one port; and an electrically actuated inner portion concentrically positioned within the outer portion and operable by the actuating mechanism to selectively block the at least one port in a first condition of the valve assembly and unblock the at least one port in a second condition of the valve assembly. A method of actuating a valve assembly in a downhole tubular.

Description:
BACKGROUND 
       [0001]    In the completion and production industry for natural resources, the formation of boreholes/completions for the purpose of production or injection of fluid is common. The boreholes/completions are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and alternatively for CO2 sequestration. Coiled tubing or string is run into the borehole/completion for varying purposes and valves, such as circulation valves, have been used on the tubing or string to enable circulation of fluids between the inside and the outside of the tubing. Such valves are typically mechanically operable including ball-activated features and pressure-operated features. 
         [0002]    The art would be receptive to improved alternative devices and methods for operating a valve within a borehole/completion. 
       BRIEF DESCRIPTION 
       [0003]    A downhole tool assembly includes a tubular having a flowbore extending along a longitudinal axis of the tubular; an electric actuating mechanism supported by the tubular and distanced from the longitudinal axis of the tubular; and, a valve assembly connected to the tubular and fluidically connected to the flowbore, the valve assembly including: an outer portion having at least one port; and an electrically actuated inner portion concentrically positioned within the outer portion and operable by the actuating mechanism to selectively block the at least one port in a first condition of the valve assembly and unblock the at least one port in a second condition of the valve assembly. 
         [0004]    A method of actuating a valve assembly in a downhole tubular, the method includes inserting a tubular having a flowbore into a borehole; employing a peripherally positioned electric motor within the tubular; actuating an electrically activated valve assembly with the motor, the valve assembly including an outer portion having at least one port and an inner portion movably configured within the outer portion; and, selectively moving the inner portion to block the at least one port in a first condition of the valve assembly and selectively moving the inner portion to expose the at least one port in a second condition of the valve assembly; wherein fluid flow through the tubular during both the first and second conditions of the valve assembly is not blocked. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0006]      FIG. 1  shows a schematic diagram of a downhole tool assembly in a borehole incorporating an exemplary electrically operable valve assembly; 
           [0007]      FIG. 2  shows a cross sectional exploded side view of an exemplary embodiment of the downhole tool assembly of  FIG. 1 ; 
           [0008]      FIG. 3  shows cross-sectional side view of an exemplary embodiment of an axially shiftable valve assembly; 
           [0009]      FIG. 4  shows a cross-sectional view of the axially shiftable valve assembly taken along line  4 - 4  of  FIG. 3 ; 
           [0010]      FIG. 5  shows a cross sectional side view of an exemplary embodiment of a rotatably adjustable valve assembly; 
           [0011]      FIG. 6  shows a cross-sectional view of the rotatably adjustable valve assembly taken along line  6 - 6  of  FIG. 5 ; 
           [0012]      FIG. 7  shows a side plan view of an exemplary inner portion of the valve assembly of  FIG. 5 ; and, 
           [0013]      FIGS. 8A-8C  show cross sectional views of alternate exemplary embodiments of a power generation sub for the downhole tool assembly of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
         [0015]      FIG. 1  shows a downhole tool assembly  100  positioned within a borehole  10  lined with a casing  12 . The borehole  10  has a generally vertical section and may further include a deviated or horizontal section  20 . Alternatively, the borehole  10  is an open-type borehole where the formation wall  16  is not lined with casing  12 . The downhole tool assembly  100  includes a tubular string  14 , such as, but not limited to, coiled tubing, production string, and drilling string. The string  14  includes any number of connected tubing pieces and may be spoolable onto a reel (not shown) provided at a surface location  22 . At a downhole end  24  of the string  14 , a tool  18  may be carried for performing a downhole operation. While illustrated at the downhole end  24 , one or more tools  18  may be provided anywhere between the downhole end  24  and surface location  22 . Alternatively, the string  14  need not include any tool  18 . The string  14  may also be used primarily for well production stages using coiled tubing, where the valve assembly  40  is employed for circulating or redirecting production fluids as needed to direct such fluids to surface, bypass blockages, etc., or for injection of stimulating or fracturing fluids as needed from an interior to an exterior of the string  14 . 
         [0016]    A power source  28  providing electrical energy may be provided at the surface location  22 , and sends an electrical signal, such as via line  30 . A surface control unit  38  is used to electrically control operation of a valve assembly  40 , such as a circulation valve, by using a motor powered by the power source  28  or a power generation sub as will be further described below. Whenever valve operation is necessary, the valve assembly  40  is activated by an actuation mechanism to move to a full or partially open condition based on required flow regimes to allow for circulation of fluids from inside to outside, outside to inside, downhole to uphole, or uphole to downhole, either as a one off operation or multi-repeated cycles. 
         [0017]    While the valve assembly  40  may be controlled via the control unit  38  at any time, whether programmed or by operator input, in an exemplary embodiment of the downhole tool assembly  100 , sensor modules  32  may also be directly incorporated into the string  14  or tool  18  to detect changes in the environment of the string  14  within the borehole  10  to indicate when an operation of a circulation valve assembly  40  is necessary. The sensor module  32  could be incorporated into a logging bottom hole assembly  34 , provided separately along interconnections of the string  14  or other locations along the string  14 , or provided within the tool  18 . The sensor module  32  may contain sensors  36 , circuitry, and processing software and algorithms relating to environment of the borehole indicative of a necessity for operation of a valve assembly  40 . Such parameters may include pressure, flow speed, and other measurements related to the environment of the string  14 . Signals from sensors  36  in the sensor module  32  or sensors  36  provided elsewhere along the string  14  are either processed by the sensor module  32 , sent to a surface location  22  such as surface control unit  38  for operator evaluation, or directly to a valve assembly  40  for immediate or subsequent action. The surface control unit  38  or processor may receive signals from the sensors  36  and processes such signals according to programmed instructions provided to the surface control unit  38 . The surface control unit  38  may also display information on a display/monitor utilized by an operator. The surface control unit  38  may include a computer or a microprocessor-based processing system, memory for storing programs or models and data, a recorder for recording data, and other peripherals. The control unit  38  may be adapted to notify the operator when operating conditions indicate a need for circulation or other valve operation. The surface control unit  38  may also be used for other operations of the string  14  and tool  18  not described herein. A communication sub (not shown) may obtain the signals and measurements and transfers the signals, using two-way telemetry, for example, to be processed at the surface location  22 . Alternatively, the signals can be processed using a downhole processor in the tool  18  or sensor module  32 . In the event a signal is sent indicating a need for circulation or other valve operation, the valve assembly  40  is electrically activated. 
         [0018]    The selective valve operation does not impede operation of the tool(s)  18 , string  14 , or any downhole procedure. Furthermore, as will be further described below, even when the valve assembly  40  is activated, flow through a flowbore  42  of the string  14  is not blocked or restricted so as to allow for flow therethrough for use by the tool  18  or downhole operations requiring such flow, such as production through the coiled tubing of the string  14 . 
         [0019]    Turning now to  FIG. 2 , the downhole tool assembly  100  is shown including the valve assembly  40 . The string  14  includes a tubular wall  44  surrounding the flowbore  42 . While the valve assembly  40  is depicted downhole of the string  14 , additional lengths of the string  14  may also be connected downhole of the valve assembly  40 . Additionally, multiple valve assemblies  40  may be provided along the string  14  as exemplified in  FIG. 1 . 
         [0020]    An exemplary embodiment of the downhole tool assembly  100  includes a logging bottom hole assembly (“BHA”)  34 . The logging BHA may be a separate component from the valve assembly  40 . Also included in the downhole tool assembly is a motor  46 , which may be incorporated into a power supply sub  48 , and an electrically activated valve assembly  40 . 
         [0021]    The logging BHA  34  is attachable to the string  14 . The logging BHA  34  includes an uphole end  54  connected to the string  14 , and a downhole end  56 . The logging BHA  34  also includes flowthrough, such that a flowbore  58  of the logging BHA  34  is in fluid communication with the flowbore  42  of the string  14 . The logging BHA  34  may create any type of geophysical log by making at least one type of measurement of rock or fluid property in the borehole  10  or within the flowbore  58  of the logging BHA  34  itself The measurements are taken using at least one type of sensor, including, but not limited to, sensors to measure pressure, temperature, spontaneous potential, and radiation, as well as a variety of sensors such as acoustic (sonic), electric, inductive, magnetic resonance, etc. One of the sensors in the logging BHA  34  may be the sensor  36  that detects environmental conditions within the borehole  10 . The data from the measurements secured by the logging BHA  34  may be recorded at the surface control unit  38 , or alternatively the logging BHA  34  may include a memory storage unit for subsequent creation of a well log. Since the information from the logging BHA  34  can be used by operators to gain an understanding of the borehole  10  for any desired downhole operation, the logging BHA  34  need not be directly part of the valve assembly  40  even if information obtained from the logging BHA  34  is utilized by the valve assembly  40 . Alternatively, the valve assembly  40  may be electrically operated using signals initiated by an operator or from other sensors  36 ,  28  as previously described. 
         [0022]    Connected downhole of string  14 , and the logging BHA  34  if utilized, is a power supply sub  48 . The power supply sub  48  includes an uphole end  60  and a downhole end  62  and includes flowthrough via a flowbore  66 . The uphole end  60  of the power supply sub  48  is connected downhole of the logging BHA  34  or string  14 . In one exemplary embodiment, a conductor  64  passes through the string  14 , logging BHA  34 , and into the power supply sub  48 . The conductor  64  is formed of one or more insulated wires or bundles of wires adapted to convey power and/or data, and may be included with or part of the signal conducting line  30  that delivers signals from the surface location  22  to motor  46 . The conductor  64  can include metal wires, or alternatively other carriers such as fiber optic cables that may be provided in a tubing encapsulated cable (“TEC”) such as an armored metal clad water sealed cable. The conductor  64  can deliver the signal provided by the sensors  28  or operator input previously described, as well as carry the signals from the downhole sensors  36 . Additionally, by use of either direct or alternating current transmittal through the conductor  64 , the power supply sub  48  is capable of providing sufficient power to operate the valve assembly  40  connected downhole of the power supply sub  48 . The conductor  64  is either provided within a protective channel (not shown) incorporated within the string  14  or passed through the flowbores  42 ,  58  of the string  14  and logging BHA  34 , such as via a wireline. Advantages of using conductor  64  to conduct current from the surface  22  include the ability to conduct high amounts of electrical energy from the surface  22  and the supply from the surface  22  is relatively unlimited. 
         [0023]    The power supply sub  48  is a tubular that peripherally supports the motor  46  and may alternatively or additionally include a power storage unit such as one or more batteries  68 . Batteries  68  can be used as a local source of power for downhole electrical devices, such as the electrically activated valve  40  or a tool  18 , but the batteries  68  must be arranged to fit within space constraints that exist within the borehole  10  and string  14 . Electrically recharging the battery  68  can occur through the conductor  64 , and replacing the battery  68 , if required, may be accomplished via a wireline operation or upon retrieval of the battery  68  from the borehole  10 . 
         [0024]    When necessary to open the valve assembly  40 , or close the valve assembly  40 , such as determined by a surface operator or via the logging BHA  34  or sensor  36  or  28  that a condition within or exterior to the string  14  has necessitated valve operation, then the power supply sub  48  will utilize an actuating mechanism linked to the motor  46  to activate the electrically operated valve assembly  40 . The electrically operated valve assembly  40  shares substantially the same flowpath, and likewise may share substantially the same longitudinal axis when interconnected with the power supply sub  48 , logging BHA  34 , and string  14 . While the valve assembly  40 , power supply sub  48 , and logging BHA  34  have been described and illustrated as separate elements, another exemplary embodiment would include the integration of any combination of such subs, although separating the components into different subs generally eases replacement of defective parts. Also, while the different subs are described as interconnected, it should be understood that the elements may be separated from each other by any additional lengths of string  14  or connectors. 
         [0025]    When actuated by the power supply sub  48 , the electrically operated valve assembly  40  will either open or close or be positioned at an interim location between fully opened and fully closed. The valve assembly  40  is accessible to the flow bore  42  of the assembly  100 , but does not block or restrict the flow bore  104  even when in use, nor does it interrupt the normal flow through the flow bore  104  and string  14 . Thus, any downhole tools, such as tool  18 , which depend on the flow through the flow bore  42 , still receive the flow. Also, the downhole tool assembly  100  is suited for well production through the flow bore  42 , since the flow bore  42  is not blocked by any of the above-described portions of the assembly  100 . 
         [0026]    As depicted in  FIGS. 3-4 , one exemplary embodiment of the valve assembly  140  includes a longitudinally displaceable or axially shiftable inner portion  110  of the valve assembly  140  that covers/blocks or uncovers/exposes at least one port  112  in an outer portion  114  of the valve assembly  140 . The outer portion  114  may be connected with the tubular of the power supply sub  48  so as to substantially share the same longitudinal axis as the power supply sub  48  and downhole tool assembly  100  and to fluidically connect with the flowbore  42  of the downhole tool assembly  100 . One exemplary embodiment of an actuating mechanism  115  to move the inner portion  110  in an uphole or downhole direction includes a screw rod  116  rotated by motor  46  within a threaded aperture  118  in the inner portion  110 . The inner portion  110  has a substantially tubular-shaped cross-section, with at least one section  120  of the inner portion  110  sized to accommodate the threaded aperture  118 . The section  120  may have a larger peripheral wall thickness than a wall thickness of the remainder of the peripheral wall. As can be mechanically understood, rotation of the screw rod  116  in a first direction will move the inner portion  110  in a downhole direction (further from surface location  22 ), while rotation of the screw rod  116  in a second direction, opposite the first direction, will move the inner portion  110  in an uphole direction. The outer portion  114  may include two or more longitudinally spaced ports  112  such that movement of the inner portion  110  in the uphole or downhole direction provides more or less fluid access between the flow bore  42  and the annulus surrounding the downhole tool assembly  100 . For example, if the inner portion is positioned as shown in  FIG. 3  in a first condition, the valve assembly  140  is fully closed/blocked. If the inner portion  110  is moved by the motor  46  to reveal all the ports  112 , then the valve assembly  140  is fully opened in a second condition of the valve assembly  140 . The valve assembly  140  may further include any number of additional conditions between fully closed and fully opened. For example, in the illustrated embodiment, if one or more of the ports  112  are unblocked, but one or more of the ports  112  are blocked, and then the motor  46  is intentionally stopped to halt further movement of the inner portion  110 , then the valve assembly  100  is in a partially opened position, a third condition. The inner portion  110  may be positionable in any of the port revealing positions described above, and may then be subsequently partially or fully closed or fully opened by selecting the appropriate rotation direction of the screw rod  116 . While the inner portion  110  has been depicted to reveal the ports  112  successively by moving the inner portion  110  in an uphole direction, alternatively the inner portion  110  could be arranged such that the inner portion  110  must move in a downhole direction to successively reveal the ports  112 . Also, while discrete axially spaced ports  112  have been illustrated, the outer portion  114  may alternatively include an elongated longitudinal slot where a third condition (between fully opened and fully closed) is achieved by halting the inner portion  110  at a position where the longitudinal slot is both partially covered and partially revealed by the inner portion  110 . In still another exemplary embodiment, the inner portion  110  may include apertures that align or misalign with the ports  112  of the outer portion  114 . 
         [0027]      FIGS. 5-7  show an alternative arrangement of a valve assembly  240  for rotatably moving the inner portion  210  relative to the outer portion  214 . An actuating mechanism  215  includes a gear set  216  that meshes with a rotatable driving gear  218  which in turn meshes with gear teeth  220  on a surface, such as an interior surface  222 , of the inner portion  210 . The gear teeth  220  need only be limited to a first section of the inner portion  210 , while a remainder of the surface  222  may be free of gear teeth  220 . The driving gear  218  is rotated in a first direction or an opposite second direction, such as by rotation of motor shaft  224  fixedly attached to an initial gear in the gear set  216 . Rotation of the driving gear  218  rotates the inner portion  210 . The inner portion  210  may be axially constrained by uphole and downhole shoulders  230 ,  232  protruding radially inwardly from outer portion  214 . The inner portion  210  includes one or more windows  226  that are alignable with or cover one or more ports  212  in the outer portion  214 . As in the valve assembly  140 , the valve assembly  240  is configured to be selectively movable between a first condition in which the valve ports  212  are fully covered by an imperforate portion  228  of the inner portion  210 , a second condition in which the valve ports  212  are completely accessible to a flow bore  42  of the downhole tool assembly  100 , and a third condition in which the valve ports  212  are only partially blocked by the imperforate portion  228  of the inner portion  210 . 
         [0028]    In other exemplary embodiments, the power supply sub  48  may include a downhole electrical generating mechanism  70  ( FIGS. 8A-8D ) to continuously generate electricity and supply electricity as needed to the motor  46  or a storage location, such as the electrical generating apparatus described by U.S. Pat. No. 5,839,508 to Tubel et al, herein incorporated by reference in its entirety. The electrical generating mechanism  70  may utilize the power of passing fluid (hydraulic energy), magnetic field, a turbine, spring energy, piezoelectrics, etc. When the power supply sub  48  is employed as a power generation sub  72 , power is scavenged, or harvested, from sources of potential energy within the borehole  10  including, but not limited to, fluids moving inside the flowbore  66 . The power generation sub  72  may harvest vibrational energy, such as the vibrational energy harvesting mechanism described by U.S. Patent Application 2009/0166045 to Wetzel et al. The flow through the flowbore  66  is a source of vibrational energy downhole, and vibration enhancement mechanisms as described in Wetzel et al. may be added in the flowbore  66  to produce a locally more turbulent flow. Additionally, vibrations created by the tool  18  are also harvestable by the power generation sub  72 . When harvesting energy from the movement of fluid within the flowbore  66 , the fluid can be used to rotate a rotatable element such as a turbine or a rotatable magnet within a coil. The rotating turbine can be connected to an electrical generator that communicates with an energy storage device, such as a battery  74 . Rotation of a magnet within a coil will induce magnetic flux on the coil and a converter can convert AC electrical output to DC electrical energy as needed. As shown in  FIG. 3A , the electrical generating mechanism  70  of the power generation sub  72  may occupy a lateral passageway  76  so as not to block the main flowbore  66 , or may alternatively be positioned within an annulus  78  surrounding the flowbore  66  as depicted in  FIG. 3B . Alternatively, as shown in  FIG. 3C , hydraulic pressure from the surface  22  can be used to generate power in an electrical generating mechanism  70  by delivering fluid under pressure via a hydraulic line  80  to react with the electrical generating mechanism  70 . 
         [0029]    In the embodiments described above, neither the valve assembly  40 ,  140 ,  240  nor the actuating mechanism  115 ,  215  required to actuate the valve assembly  40 ,  140 ,  240  block flow through the flowbore of the downhole tool assembly  100 . Any of the above described embodiments of an electrically operated valve assembly and power supply sub may be used in plurality and sections of string  14  may be interposed therebetween. While fluid flow is illustrated in one particular direction, it should be understood that the fluid flow within the flowbores  42 ,  58 ,  66 ,  104  of the above described exemplary embodiments may be in either uphole or downhole direction depending upon the particular application of the string. 
         [0030]    A method of operating a valve assembly  40 ,  140 ,  240  in a downhole tool assembly  100  includes inserting a tubular such as the string  14  into the borehole  10 , determining a need for opening or blocking flow between the flowbore of the tubular and the annulus between the tubular and the borehole  10 , sending a signal to a control unit  28  or motor  46  in response to the determined need, actuating an electrically activated valve assembly  40 , the valve assembly  40  having a flow bore  104  fluidically connected to a flowbore  42  of the tubular, and altering the flow between the tubular and surrounding borehole  10  by operation of the valve assembly  40 . The method enables a partial opening of flow between the flowbore and annulus. Flow through the flowbores  42 ,  104  of the string  14  and valve assembly  40  is not blocked during activation and non-activation of the valve assembly  40 . The method further includes generating power in a power generating sub  48 . 
         [0031]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.