Patent Publication Number: US-10323468-B2

Title: Well integrity monitoring system with wireless coupler

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present document is based on and claims priority to U.S. Provisional Application Ser. No. 62/008,205, filed Jun. 5, 2014 and U.S. Provisional Application Ser. No. 62/014,499, filed Jun. 19, 2014, both of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     A wide variety of well equipment may be installed in a well to facilitate operation and monitoring of the well. For example, the well equipment may comprise completion systems installed in a wellbore to enable production of hydrocarbon fluids, such as oil and gas, or to facilitate injection of fluids into the well. The well equipment often includes electrical devices which are powered. In some applications, the electrical devices also provide data which is transmitted to a control system located at a surface of the earth or at another suitable location. In some applications, the power and/or data signals may be transmitted through inductive couplers. However, the inductive couplers can detrimentally provide an obstruction with respect to passage of control lines and/or fluids. 
     SUMMARY 
     In general, a system and methodology are provided for utilizing a wireless coupler system with tubing, e.g. well casing, to communicate signals from and/or to a device, e.g. sensor, external to the tubing. According to an embodiment, the wireless coupler system comprises an inductive coupler system formed with a female inductive coupler disposed along a casing and a male inductive coupler mounted along tubing disposed within the casing. The female inductive coupler is operatively coupled with the device/sensor and the male inductive coupler is operatively coupled with a communication line routed along the tubing. The wireless, e.g. inductive, coupler system is constructed to facilitate alignment of the male coupler with the female coupler as the tubing is moved along an interior of the casing. Additionally, the wireless coupler system may be constructed with bypass channels to facilitate flow of fluid and routing of communication lines through the wireless coupler system. 
     However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and: 
         FIG. 1  is a schematic illustration of an example of a well system utilizing a wireless coupler system in a wellbore, according to an embodiment of the disclosure; 
         FIG. 2  is a schematic illustration of an inductive coupler system disposed to communicate signals across a casing, according to an embodiment of the disclosure; 
         FIG. 3  is a schematic illustration of another example of an inductive coupler system disposed to communicate signals across a casing, according to an embodiment of the disclosure; 
         FIG. 4  is a cross-sectional view of an example of an inductive coupler system, according to an embodiment of the disclosure; 
         FIG. 5  is an orthogonal view of tubing having a male inductive coupler being moved into casing to align the male inductive coupler with a female inductive coupler mounted along an exterior of the casing, according to an embodiment of the disclosure; 
         FIG. 6  is a schematic illustration of another embodiment of an inductive coupler system disposed in a well system to communicate signals across a casing, according to an embodiment of the disclosure; 
         FIG. 7  is a schematic illustration similar to that of  FIG. 6  but showing the inductive coupler system and the well system in a different operational position, according to an embodiment of the disclosure; and 
         FIG. 8  is a schematic illustration similar to that of  FIG. 7  but showing the inductive coupler system and the well system in a different operational position, according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. 
     The disclosure herein generally involves a system and methodology for utilizing a wireless coupler system to communicate signals, e.g. data and/or power signals, across a tubing, e.g. casing. The wireless coupler system facilitates alignment of a male coupler with a female coupler while on interior and exterior sides of the casing, respectively. In an embodiment, the wireless coupler system comprises an inductive coupler system which may be used with well casing deployed along a subsea wellbore extending into a subterranean formation. The inductive coupler system comprises an inner or male inductive coupler and an outer or female inductive coupler each having an inductive coil. In well applications, the inner or male inductive coupler may be mounted on tubing and moved into a surrounding casing until aligned with the female inductive coupler for communication of signals across the casing. 
     According to an embodiment, the inductive coupler system is constructed with a female inductive coupler disposed along an exterior of a well casing and a male inductive coupler is mounted along tubing disposed within the casing. For example, the tubing may be a well string which is moved into a surrounding well casing until the male inductive coupler is properly aligned with the female inductive coupler. The female inductive coupler may be operatively coupled with a device, e.g. sensor, disposed externally of the well casing. By way of example, the sensor may be a pressure sensor position to monitor pressure in an annulus surrounding the casing. However, the sensor may comprise various other and/or additional sensors such as temperature sensors, flow sensors, resistivity sensors, and/or other suitable sensors. 
     In this example, the male inductive coupler is operatively coupled with a communication line routed along the tubing. For example, the male inductive coupler may be connected with an electrical or optical fiber communication line which is routed uphole along the tubing to a control system located at the surface or at another suitable location. The inductive coupler system is constructed to facilitate alignment of the male inductive coupler with the female inductive coupler to help optimize transmission of signals between the exterior and interior of the casing once the tubing has been moved to a desired position within the casing. However, the alignment techniques described herein may be employed with other wireless coupling systems. Additionally, the wireless, e.g. inductive, coupler system may be constructed with bypass channels to facilitate flow of fluid and routing of communication lines through the wireless coupler system. The bypass channels enable substantial fluid flow when, for example, deploying the tubing string downhole or when killing the well. The bypass channels also provides space for a variety of communication lines, e.g. electrical lines, fiber-optic lines, hydraulic lines, chemical injection lines, and/or other lines, routed along the tubing and through the wireless coupler system. 
     In many applications, data may be sent from or to the sensor (or other electrical device) across the casing via the inductive coupler system. Depending on the application, power signals also may be transferred across the casing via the inductive coupler system. However, the data signals and/or power signals also may be transferred across the casing via other types of wireless coupler systems, e.g. toroidal coupler systems. In an inductive coupler system embodiment, a male inductive coupler is positioned at a location which allows it to cooperate with the outer, female inductive coupler for transmitting signals across the casing. Embodiments described herein use induction principles to enable power and/or information data to be conveyed between the male and female inductive couplers. The male inductive coupler and the female inductive coupler each may comprise, for example, at least one coil, a magnetic core, and a metal sleeve enclosing the at least one coil and magnetic core. The coil and magnetic core of the male inductive coupler are moved via the tubing into substantially radial alignment with the coil and magnetic core of the female inductive coupler to facilitate inductive transfer of power and/or data signals. 
     A magnetic field is created by running electrical current through the coil or coils of one of the inductive couplers. The electrical current induces a current flow in the opposed coil or coils of the other inductive coupler. This allows power and/or data signals to be transferred across the casing, i.e. across the casing wall. In embodiments described herein, the configuration of the inductive coupler system enables desirable alignment of the male inductive coupler with the female inductive coupler while also enabling passage of substantial fluid flows and communication lines through the inductive coupler system. In some applications, the male inductive coupler may be positioned along a tubing while being decoupled from the tubing. For example, the male inductive coupler may be slid over the tubing so that the tubing integrity is not compromised by threadably or otherwise engaging the male inductive coupler with the tubing. By decoupling the male inductive coupler from the tubing, the male inductive coupler is not subjected to various tubing loads, e.g. tension, compression, torsion, differential pressure across tubing, and/or other loads. Consequently, the male inductive coupler may be constructed more economically from lower grade material than that used for the tubing material. In some applications, the female inductive coupler may be similarly decoupled from the casing. 
     Referring generally to  FIG. 1 , an example of a well system  20  having a wireless coupler system  22  is illustrated. In embodiments described below, the wireless coupler system  22  is in the form of an inductive coupler system, but other wireless coupler systems, e.g. toroidal systems, also may be employed. The well system  20  comprises at least one and often a series of casings  24  which may be disposed along a wellbore  25  drilled into a subterranean formation  26 . In this example, the well system  20  is a subsea well system and the wellbore  24  is drilled into formation  26  beneath a seabed  28 . A tubing  30 , e.g. a well tubing string, is deployed downhole along an interior of the internal casing  24 . Additionally, the inductive coupler system  22  is positioned to facilitate communication of signals, e.g. data and/or power signals, across the corresponding casing  24 . In some well applications, the well casing(s)  24  may be formed of non-magnetic, low conductivity metal. 
     The wireless coupler system  22  comprises a female coupler  32 , e.g. a female inductive coupler  32 , which may be mounted along an exterior of the corresponding casing  24 . Additionally, the wireless coupler system  22  comprises a male coupler  34 , e.g. a male inductive coupler  34 , positioned to the interior of the same casing  24 . By way of example, the female inductive coupler  32  may be mounted to an exterior  36 , e.g. outside surface, of casing  24  and the male inductive coupler  34  may be mounted along an exterior  38  of tubing string  30 . In an embodiment, the female inductive coupler  32  may be slid over the casing  24  and/or the male inductive coupler  34  may be slid over the tubing  30 . By sliding the female inductive coupler  32  over the casing  24  and/or the male inductive coupler  34  over the tubing  30 , the couplers may effectively be decoupled from the corresponding casing/tubing. As described in greater detail below, the inductive coupler system  22  may comprise a passage or a plurality of passages to accommodate fluid flow therethrough as well as the routing of a communication line or lines  40  therethrough. Examples of communication lines  40  include hydraulic lines, electrical lines, fiber-optic lines, chemical injection lines, and other types of lines routed downhole along tubing  30 . In the specific example illustrated, the communication line(s) extends through the male inductor coupler  34 . 
     According to an embodiment, the female inductive coupler is operatively coupled with a sensor or other electrical device  42  located outside of the subject casing  24 . For example, the sensor  42  may be positioned in an annulus  44 , sometimes referred to as a B-annulus, which is located outside of the subject casing  24  and externally of the A-annulus  46  between tubing string  30  and the subject casing  24 . In some applications, the sensor  42  may comprise a pressure sensor  48 , e.g. a pressure gauge, to monitor pressure along the B-annulus  44  and the pressure data be used to determine well integrity. However, the sensor  42  may comprise a variety of other and/or additional sensors, including temperature sensors, resistivity sensors, flow sensors, or other suitable sensors for a given well application. The sensor  42  is coupled with female inductive coupler  32  so that signals may be wirelessly transferred across casing  24  to male inductive coupler  34 . Depending on the application, data and/or power signals may be transferred across casing  24  to or from the sensor/electrical device  42 . 
     As further illustrated in  FIG. 1 , a variety of other sensors, e.g. sensors  50  and  52 , may be employed in well system  20 . In some applications, the lower sensor  52  may be a pressure sensor positioned in the A-annulus  46  to monitor pressure along the tubing  30 . However, a variety of additional and/or other types of sensors may be positioned along the tubing string  30  for monitoring a variety of desired parameters. Depending on the application, the sensors  50 ,  52  may be coupled with the male inductive coupler  34  or they may be coupled with communication lines routed through the male inductive coupler  34  to a control system, e.g a computer-based control system located at the surface. It should be noted that in some applications, the inductive coupler system  22  may be located a relatively short distance  54 , e.g. 10 feet, below the seabed  28 . However, other applications may position the inductive coupler system  22  at a variety of depths along the casing  24  and tubing string  30 . 
     Referring generally to  FIG. 2 , an enlarged example of inductive coupler system  22  is illustrated as deployed along casing  24  and tubing  30 . In this example, the casing  24  may be suspended from a tubing hangar  56  and tubing  30  may be in the form of a tubing string having a hollow interior  58  and deployed downhole along the interior of casing  24 . In some examples, the tubing  30  may be formed by coupling a plurality of tubing joints  60  together via tubing connectors  62 . Sometimes casing joints of casing  24  also may be coupled together by similar connectors  62 . However, tubing  30  and casing  24  each may have a variety of configurations and may include several types of tubing string or casing string components. 
     In the example illustrated, female inductive coupler  32  may be in the form of a slip on coupler which is slid along an exterior of casing  24  and secured at a desired location by a suitable fastener  64 , such as a threaded fastener, lock ring, weldment, releasable collar, or other suitable fastener  64 . The female inductive coupler  32  may comprise a body  66  and at least one coil  68  mounted within the body  66 . The coil is coupled with electrical device/sensor  42  via a communication line  70  for transmitting power and/or data signals to or from the electrical device/sensor  42 . In some applications, the electrical device/sensor  42  may be positioned within a housing  72  which may be in the form of a protective clamp or other housing constructed to secure and protect the device/sensor  42  along an exterior of casing  24 . 
     Referring again to the example of  FIG. 2 , the male inductive coupler  34  may be in the form of a slip on coupler which is slid along exterior  38  of tubing  30  and secured at a desired location by, for example, a suitable clamping mechanism  74 . The mail inductive coupler  34  may comprise a body  76  and at least one coil  78  mounted within the body  76 . The coil  78  may be coupled with a suitable communication line  40 , such as an electrical communication line  80  via, for example, a splice  82 . As discussed above, the well system  20  may utilize a variety of communication lines  40  depending on the application. For example, additional electrical and/or optical fiber communication lines  84  may be routed through inductive coupler system  22 , e.g. through male inductive coupler  34 . Other types of communication lines, such as hydraulic and/or chemical injection lines  86  also may be routed through inductive coupler system  22 , e.g. through male inductive coupler  34 . 
     In the example illustrated, the inductive coupler system  22  utilizes clamping mechanism  74  to secure male inductive coupler  34  at the desired location along tubing  30 . According to an embodiment, the clamping mechanism of inductive coupler system  22  may comprise clamping mechanism housings  88  positioned on opposite axial sides of male inductive coupler  34 . The clamping mechanism housings  88  cooperate with an alignment mechanism  89  in the form of spacers  90  positioned between the clamping mechanism housings  88  and male inductive coupler  34 . The spacers  90  may be in the form of spacer tubes and are used to position and lock the male inductive coupler  34  against axial and rotational movement with respect to tubing  30 . Additionally, the clamping mechanism housings  88  may serve as protective housings for protecting certain components, such as splice  82  and communication lines  80 ,  84 ,  86 . 
     As illustrated, a passage  92  or a plurality of passages  92  may be located through male inductive coupler  34  to serve as bypass channels. The bypass channel or channels  92  are sufficiently sized to accommodate substantial fluid flow, as represented by arrows  94 . The bypass channel or channels  92  also provide space and a routing path for routing the desired communication lines, e.g. communication lines  84 ,  86 , through the inductive coupler system  22  by providing a passage through the male inductive coupler  34 . The bypass channel(s)  92  thus can be used to facilitate both flow of fluid and routing of communication lines through the inductive coupler system  22 . The bypass channels  92  enable substantial fluid flow when, for example, deploying the tubing string  30  downhole or when killing the well. By forming bypass channels  92  of sufficient size, space is provided for many types of communication lines, e.g. electrical lines, fiber-optic lines, hydraulic lines, chemical injection lines, and/or other lines, routed along the tubing  30  and through the inductive coupler system  22 . 
     Referring generally to  FIG. 3 , another embodiment of inductive coupler system  22  is illustrated. In this example, the spacers  90  each are constructed with a pair of spacer tubes  96  connected to each other by a member  98 , e.g. pin member. For example, the pair of spacer tubes  96  may be in the form of concentric spacer tubes coupled by member  98  in the form of at least one pin. By using pin members  98 , the male inductive coupler  34  may be easily spaced out between clamping mechanism housings  88 . 
     In  FIG. 4 , a cross-sectional view of the inductive coupler system  22  is provided to illustrate an example of an arrangement of bypass channels  92 . In this example, tubing  30  comprises production tubing and male inductive coupler  34  is slid onto the production tubing to a desired location and then moved into casing  24  until properly aligned with female inductive coupler  32 . The male inductive coupler  34  may be positioned securely along exterior  38  of tubing  30  via radial structures  100  to centralize the male inductive coupler  34  with respect to tubing  30  and to form bypass channels  92  between the radial structures  100 . In the specific example illustrated, three bypass channels  92  are located between three radial structures  100 . However, the number of bypass channels  92  and radial structures  100  may be adjusted according to the parameters of a given application. As illustrated, the bypass channels  92  provide substantial radial depth  101  and circumferential length between structures  100  to accommodate substantial fluid flow through male inductive coupler  34  and thus through inductive coupler system  22 . The communication lines, e.g. communication lines  84 ,  86 , may be routed along one or more of the bypass channels  92 . 
     Depending on the application, the female inductive coupler  32 , male inductive coupler  34 , and corresponding clamping mechanisms, e.g. clamping mechanism  74 , may have a variety of configurations. As illustrated by the example in  FIG. 5 , the male inductive coupler  34  may comprise a plurality of metal straps combined with and held in place via the unitary clamping mechanism  74 . The metal straps/unitary clamping mechanism  74  ensure that the coil/coils  78  may be secured along tubing  30  as the tubing  30  is slid into the casing  24  to which the female inductive coupler  32  is mounted (with corresponding coils  68 ). The clamping mechanism  74  may be constructed to accommodate various bypass channels  92  and other components, such as a sensor  102 . The bypass channels  92  may be routed through male inductive coupler  34  in a manner similar to that of the embodiment described above with reference to  FIGS. 2-4 . However, many other arrangements of clamping mechanisms, sensors, and/or coils may be utilized in a given inductive coupler system  22 . 
     Referring generally to  FIGS. 6-8 , another embodiment of inductive coupler system  22  is illustrated. In this embodiment, the male inductive coupler  34  is allowed to float rather than being held by spacers  90 . A securing member  104  may be used to hold the male inductive coupler  34  at a desired location along tubing  30  while moving downhole. By way of example, the securing member  104  may comprise a shear member or a spring  106 . In the example illustrated, spring  106  is positioned between the body  76  of male inductive coupler  74  and an adjacent cross coupling clamping mechanism housing  88 . The communication line  80 , e.g. cable, coupled with coil  78  of male inductive coupler  34  may be wrapped around tubing  30  in a coil  108  adjacent spring  106 . The coil  108  provides slack in the communication line  80  and thus allows the decoupled male inductive coupler  34  to float between clamping mechanism housings  88 . 
     As illustrated in  FIG. 6 , the alignment mechanism  89  may be in the form of a positioning member  110  coupled with the body  76  of male inductive coupler  34 . By way of example, the positioning member  110  comprises a collet or sleeve  112  having an engagement end  114 . In some applications, the engagement end  114  may comprise an engagement feature  116 , such as a spring-loaded dog  118  or other suitable engagement feature. In this type of embodiment, rotation of male inductive coupler  34  relative to tubing  30  may be blocked via an anti-rotation mechanism  120 . By way of example, the anti-rotation mechanism  120  may comprise a pin  122  extending from sleeve  112  into a slot  124  formed in one of the cross coupling clamping mechanism housings  88 . The pin  122  and corresponding slot  124  enable movement of male inductive coupler  34  along tubing  30  in an axial direction while blocking relative rotational movement of coupler  34  with respect to tubing  30 . 
     When tubing  30  is deployed downhole into casing  24 , the positioning member  110  moves along the interior of casing  24  until engagement end  114 , e.g. spring-loaded dog  118 , is received in a corresponding profile  126 , e.g. recess, disposed along the interior of casing  24 , e.g. within one of the casing connectors  62 . As illustrated in  FIG. 7 , the engagement end  114  engages the corresponding profile  126  and effectively positions the coil  78  of male inductive coupler  34  adjacent the corresponding coil  68  of female inductive coupler  32 . This provides a dependable mechanism for properly aligning the male inductive coupler  34  and female inductive coupler  32  both axially and radially to optimize data transmission across casing  24 . The floating nature of male inductive coupler  34  along with spring  106  and coil  108  enable movement of tubing  30 , as illustrated in  FIG. 8 , without affecting the proper alignment of male inductive coupler  34  and female inductive coupler  32 . 
     In this latter embodiment, the floating male inductive coupler  34  maintains a similar bypass channel  92  for both fluid flow  94  and routing of communication lines, e.g. communication lines  84 ,  86 . Regardless of the position of male inductive coupler  34  relative to the corresponding clamping mechanism housings  88 , fluid is free to flow past the inductive coupler system  22  via bypass channels  92 . The coil  108  enables floating of the male inductive coupler  34  without stressing or otherwise affecting the connection between coupler coil  78  and electric communication line  80 . 
     Depending on the parameters of a given application, the structure and components of the wireless coupling system  22 , casing  24 , devices/sensors  42 ,  50 ,  52 , and control system to which the devices/sensors are coupled may vary. For example, the wireless coupling system  22  may be an inductive coupling system as described in embodiments above, but the wireless coupling system also may comprise a variety of other wireless coupling systems which utilize the alignment techniques and/or bypass channels described herein. The wireless coupling system  22  may be constructed to facilitate alignment of various types of wireless couplers  32 ,  34 . Additionally, casing  24  may be constructed in a variety of sizes and configurations along the wellbore  25  for cooperation with many types of well completions and other downhole equipment. In some applications, the casing may comprise a non-well related casing. Similarly, the devices/sensors  42 ,  50 ,  52  may comprise many types of sensors, e.g. pressure sensors, temperature sensors, resistivity sensors, flow sensors, and/or other sensors deployed to monitor well related parameters external to the casing or both external and internal to the casing. The control system to which the devices/sensors are coupled also may comprise various types of power supplies and/or processing systems for processing data transmitted uphole with the aid of inductive coupler system  22 . 
     The inductive coupler system  22  also may comprise many configurations of female inductive couplers and male inductive couplers. In some applications, each of the female and male inductive couplers comprises a single coil. However, other applications may utilize two or more coils in each of the female and male inductive couplers. Various materials, e.g. various metals, also may be used to form the components of inductive coupler system  22 . Similarly, the number of turns of each coil and the electromagnetic circuitry associated with those coils may vary according to the configuration of the inductive coupler system and the environment in which the system is operated. Various mechanism configurations also may be used to ensure the inductive couplers are moved into close proximity with each other during alignment. In some applications, the inductive couplers are slid onto the tubing or casing, but other applications may utilize integrated couplers. For example, the female inductive coupler  32  may be part of an assembly and corresponding sections of the casing may be made up to the assembly. 
     Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.