Patent Publication Number: US-10760362-B2

Title: Systems and methods for a release device

Description:
BACKGROUND 
     This disclosure relates to systems and methods to release a downhole device in a wellbore, which may enable other downhole devices to continue receiving power. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, these statements are to be read in this light, and not as admissions of any kind. 
     To locate and extract resources from a well, a wellbore may be drilled into a geological formation. Downhole devices, such as toolstrings and sensors, may be placed into the wellbore to obtain measurements relating to the wellbore. In some cases, several downhole devices may be connected in a string of downhole devices connected to each other. The string of downhole devices may receive electrical power from upstream power sources at the surface or from a battery located in another downhole device. Multiple electrical leads, which may include wires or other conductors, may provide the electrical power to each of the downhole devices. 
     In some situations, one of the downhole devices may be released into the wellbore, causing that downhole device to become mechanically and electrically decoupled from the string of downhole devices. When this happens, the electrical leads between the released downhole device and the remaining string of downhole devices may become exposed to fluid present in the wellbore, which may short electrical leads still receiving electricity. This may effectively deactivate not just the downhole device that was released, but also the remaining string of downhole devices that were not released. 
     SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     In one example, a system includes a downhole tool having multiple electric leads. The system also includes a release device that includes an outer shell configured to mechanically couple to the downhole tool, and the outer shell is configured to form a cavity that is fluidly separate from wellbore fluids contained within a wellbore while the outer shell is mechanically coupled to the downhole tool. The release device also includes a contact block configured to electrically couple to the multiple electric leads. In addition, the contact block is configured to electrically decouple from the multiple electric leads while the outer shell remains mechanically coupled to the downhole tool. Further, the contact block is configured to remain in the cavity after electrically decoupling from the plurality of electric leads. 
     In another example, a method includes electrically decoupling a contact block of a release device from multiple electric leads of a downhole tool while maintaining a fluid separation between the contact block and wellbore fluids contained within a wellbore. The method also includes mechanically decoupling an outer shell of the release device after electrically decoupling the contact block from the multiple electric leads. 
     In yet another example, a system includes a first downhole tool having a first multiple electric leads and a first release device that includes a first outer shell configured to mechanically couple to the first downhole tool. Further, the first outer shell is configured to form a first cavity that is fluidly separate from wellbore fluids contained within a wellbore while the first outer shell is mechanically coupled to the first downhole tool. The first release device also includes a first contact block configured to electrically couple to the first multiple electric leads. Moreover, the first contact block is configured to electrically decouple from the first multiple electric leads while the first outer shell remains mechanically coupled to the first downhole tool. In addition, the first contact block is configured to remain in the first cavity after electrically decoupling from the first multiple of electric leads. The system also includes a second downhole tool having a second multiple of electric leads and a second release device that includes a second outer shell configured to mechanically couple to the second downhole tool. Further, the second outer shell is configured to form a second cavity that is fluidly separate from wellbore fluids contained within the wellbore while the second outer shell is mechanically coupled to the second downhole tool. In addition, the second release device includes a second contact block configured to electrically couple to the second multiple of electric leads. Moreover, the second contact block is configured to electrically decouple from the second multiple of electric leads while the second outer shell remains mechanically coupled to the second downhole tool. Further, the second contact block is configured to remain in the second cavity after electrically decoupling from the second multiple of electric leads. 
     Various refinements of the features noted above may be undertaken in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. The brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a schematic diagram of a wireline system that includes a toolstring to detect properties of a wellbore or geological formation adjacent to the toolstring, in accordance with an aspect of the present disclosure; 
         FIG. 2  illustrates an embodiment of the toolstring of  FIG. 1  with a first downhole tool, a second downhole tool, a third downhole tool, a first release device coupled to the first downhole tool, and a second release device coupled to the second downhole tool; 
         FIG. 3  illustrates the toolstring of  FIG. 1  with a driveshaft, a downhole tool, and a release device; 
         FIG. 4  illustrates a contact block electrically decoupled from the downhole tool of  FIG. 3 ; and 
         FIG. 5  is a flowchart of an embodiment of a process for electrically and mechanically decoupling the release device of  FIG. 3  from the downhole tool of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. These described embodiments are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
     The present disclosure relates to devices that improve the ability to release downhole tools in a wellbore while maintaining a flow of electricity to other downhole tools in a wellbore. Toolstrings containing downhole tools may be placed into the wellbore to gather information about the geological formation. Multiple electrical leads (e.g., wires, conductors, etc.) may be coupled to each of the downhole tools to provide power to the downhole tools. In some situations during an operation within the wellbore, one of the downhole tools may be released into the wellbore. It is desirable to release a downhole tool while maintaining a flow of electricity to other downhole tools that are not released. 
     Accordingly, embodiments of this disclosure relate to systems and methods for releasing a downhole tool with multiple electrical leads. That is, some embodiments include a release device coupled to a downhole tool and multiple electrical leads that provide power to one or more downhole tools. The release device may be able to decouple the electrical leads from the downhole tool before mechanically decoupling from the downhole tool. Decoupling the electrical leads first may enable electricity to continue to flow to other downhole tools upstream of the downhole tool being decoupled. 
     With this in mind,  FIG. 1  illustrates a well-logging system  10  that may employ the systems and methods of this disclosure. The well-logging system  10  may be used to convey a toolstring  12  through a geological formation  14  via a wellbore  16 . Further, the wellbore  16  may not continue straight down into the geological formation  14 , and the wellbore  16  may contain a turn  13 . The wellbore  16  may continue past the turn into the geological formation  14  at an angle as high as ninety degrees. In the example of  FIG. 1 , the toolstring  12  is conveyed on a cable  18  via a logging winch system (e.g., vehicle)  20 . Although the logging winch system  20  is schematically shown in  FIG. 1  as a mobile logging winch system carried by a truck, the logging winch system  20  may be substantially fixed (e.g., a long-term installation that is substantially permanent or modular). Any suitable cable  18  for well logging may be used. The cable  18  may be spooled and unspooled on a drum  22  and an auxiliary power source  24  may provide energy to the logging winch system  20 , the cable  18 , and/or the toolstring  12 . 
     Moreover, while the toolstring  12  is described as a wireline toolstring, it should be appreciated that any suitable conveyance may be used. For example, the toolstring  12  may instead be conveyed on a slickline or via coiled tubing, as part of a pump down perforation application, as part of a tough logging conditions (TLC) operation, as part of a tubing-conveyed perforating (TCP) operation, or as a logging-while-drilling (LWD) tool as part of a bottom hole assembly (BHA) of a drill string, and so forth. For the purposes of this disclosure, the toolstring  12  may include any suitable tool that utilizes electricity, such as a sensor to obtain measurements of properties of the geological formation  14 , a drilling tool, a material collection tool, tractor tool, etc. The toolstring  12  may include multiple downhole tools, such as 2, 3, 4, 5, 6, or more downhole tools to conduct operations in the wellbore  16 . 
     The toolstring  12  may emit energy into the geological formation  14 , which may enable measurements to be obtained by the toolstring  12  as data  26  relating to the wellbore  16  and/or the geological formation  14 . The data  26  may be sent to a data processing system  28 . For example, the data processing system  28  may include a processor  30 , which may execute instructions stored in memory  32  and/or storage  34 . As such, the memory  32  and/or the storage  34  of the data processing system  28  may be any suitable article of manufacture that can store the instructions. The memory  32  and/or the storage  34  may be read-only memory (ROM), random-access memory (RAM), flash memory, an optical storage medium, or a hard disk drive, to name a few examples. A display  36 , which may be any suitable electronic display, may display the images generated by the processor  30 . The data processing system  28  may be a local component of the logging winch system  20  (e.g., within the toolstring  12 ), a remote device that analyzes data from other logging winch systems  20 , a device located proximate to the drilling operation, or any combination thereof. In some embodiments, the data processing system  28  may be a mobile computing device (e.g., tablet, smart phone, or laptop) or a server remote from the logging winch system  20 . 
       FIG. 2  illustrates an embodiment of the toolstring  12  having a first downhole tool  50 , a second downhole tool  52 , a third downhole tool  54 , a first release device  56  coupled to the first downhole tool  50 , and a second release device  58  coupled to the second downhole tool  52 . The toolstring  12  may descend into the wellbore  16  to perform various operations (e.g., data gathering, sample collection, drilling, etc.). The cable  18  may be used to provide power to the first downhole tool  50 , the second downhole tool  52 , the third downhole tool  54 , the first release device  56 , and the second release device  58 . In some embodiments, a battery may be used to provide power. Multiple electrical leads may be used to provide power to the downhole tools  50 ,  52 ,  54 . In some operations, it may be beneficial to release one or more of the downhole tools  50 ,  52 ,  54  into the wellbore  16  due to foreseen or unforeseen circumstances, such as one of the downhole tools  50 ,  52 ,  54  getting stuck in the wellbore  16 . Accordingly, one of the release devices  56 ,  58  may be used to decouple the respective downhole tool while maintaining the electrical connections of downhole tools upstream of the release device. Maintaining the electrical connections of upstream downhole tools may enable the upstream downhole tools to continue being fully operational, which facilitates further operation of the toolstring  12  (e.g., retracting the toolstring  12  to the surface). 
     The present embodiment includes two release devices  56 ,  58 , which provides more flexibility to an operator on the surface. For example, if the second downhole tool  52  is stuck, causing the toolstring  12  to be stuck, utilizing the first release device  56  to decouple the first downhole tool  50  is unlikely to affect the second downhole tool  52 . As such, the second release device  58  may be used to decouple the second downhole tool  52  from the toolstring  12 , thereby enabling the toolstring  12  to move freely within the wellbore  16 . 
       FIG. 3  illustrates the toolstring  12  having a driveshaft  70 , a downhole tool  72 , which may be first or second downhole tool  50 ,  52  shown in  FIG. 2 , and a release device  74 , which may be first or second release device  56 ,  58  shown in  FIG. 2 . As discussed above, the release device  74 ,  56 ,  58  may be used to electrically decouple the downhole tool  72 ,  50 ,  52  from the toolstring before mechanically decoupling the downhole tool  72 ,  50 ,  52  from the toolstring  12 . As such, the release device  74  includes a contact block  76  that receives electricity (e.g., from a wire, conductor, battery, etc.), and electrically couples the release device  74  to the downhole tool  72  (e.g., via electrical pins). The contact block  76  includes a mounting portion  78  that couples the contact block  76  to a rotating shaft  80 , which couples to the driveshaft via a rotating joint  82  (e.g., a U-joint). 
     The release device  74 ,  56 ,  58  also includes an outer shell  84 , which mechanically couples to the downhole tool  72 ,  50 ,  52  and provides a physical barrier between the contact block  76  and an interior  86  of the wellbore  16 . The interior  86  of the wellbore  16  contains wellbore fluids, which may include a slurry of different materials (e.g., pumping fluids, particles from the formation  14 , etc.). The fluids within the wellbore may conduct electricity, thereby causing an electrical shorting risk if electrical leads come into contact with the wellbore fluids. Accordingly, the outer shell  84  protects the electrical components contained within the release device  74 . 
     The rotating shaft  80  and the mounting portion  78  include threads  88  to enable the contact block  76  to electrically decouple from the downhole tool  72 ,  50 ,  52 . For example, when releasing the downhole tool  72 , the driveshaft  70  may be driven into rotation (e.g., by a motor  81 ) to cause the rotating shaft  80  to also rotate via the rotating joint  82 . The threads  88  of the rotating shaft  80  drive the mounting portion  78  into rotation, and cause the mounting portion  78  and the contact block  76  to move in an upstream direction  90  into a cavity  92  of the release device that is interior to the outer shell  84 . As the contact block  76  moves in the upstream direction  90 , the contact block  76  electrically decouples from the downhole tool  72 . For example, the electric coupling and the downhole tool  72  may be electrically coupled via multiple electrical leads (e.g., conductors, pins, or wires). 
     The motor  81  (e.g., an electric motor) may be controlled by a motor controller  83 . In certain embodiments, the motor controller  83  is an electronic controller having electrical circuitry that may receive a signal indicative of a decoupling procedure. Based at least partly on the signal indicative of the decoupling procedure, the motor controller  83  may direct the motor  81  to rotate the driveshaft  70  to cause electrical and mechanical decoupling of the release device  74 ,  56 ,  58  from the downhole tool  72 ,  50 ,  52 . In the illustrated embodiment, the motor controller  83  includes a processor, such as the illustrated microprocessor  85 , and a memory device  87 . The motor controller  83  may also include one or more storage devices and/or other suitable components. The microprocessor  85  may be used to execute software, such as software for controlling the motor  81 , and so forth. Moreover, the microprocessor  85  may include a single microprocessor, multiple microprocessors, and/or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the microprocessor  85  may include one or more reduced instruction set (RISC) processors. 
     The memory device  87  may include a volatile memory, such as random access memory (RAM), and/or a nonvolatile memory, such as read-only memory (ROM). The memory device  87  may store a variety of information and may be used for various purposes. For example, the memory device  87  may store processor-executable instructions (e.g., firmware or software) for the microprocessor  85  to execute, such as instructions for controlling the motor  81 . The storage device(s) (e.g., nonvolatile storage) may include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The storage device(s) may store data, instructions (e.g., software or firmware for controlling the motor  81 , etc.), and any other suitable data. Further, the motor controller  83  may be located in any suitable location, such as along the toolstring  12 , within or external to the motor  81 , at the surface, etc. Further, the motor controller  83  may be part of the data processing system of  FIG. 1 . 
       FIG. 4  illustrates the contact block  76  electrically decoupled from the downhole tool  72 ,  50 ,  52 . As discussed above, rotation of the mounting portion  78  may cause the contact block  76  to move in an upstream direction  90 . As the contact block  76  moves in the upstream direction  90 , the contact block  76  decouples from electric leads  94  (e.g., pins) of the downhole tool  72 ,  50 ,  52 . Because the entire contact block  76  move in the upstream direction  90  in unison, the contact block  76  may decouple from multiple electric leads  94  at one time. In the present embodiment, the contact block  76  decouples from four electric leads  94  at one time. In some embodiments, the contact block  76  may decouple from any suitable number of electric leads  94 , including 1, 2, 3, 5, 6, or more. Further, in the present embodiment, the electric leads  94  have a substantially uniform size in shape. In some embodiments, the electric leads  94  may have varying sizes and shapes. For example, some electric leads may be wider, thinner, longer, shorter, etc. than other electric leads. 
     After the contact block  76  has been electrically decoupled from the electric leads  94 , the release device  74 ,  56 ,  58  may be mechanically decoupled from the downhole tool  72 ,  50 ,  52 . Further, the electric leads  94  may still be within the cavity  92  of the release device, and thus still isolated from the interior  86  of the wellbore  16 . In the present embodiment, the rotating shaft  80  includes a screw  96  that enables the release device to mechanically decouple from the downhole tool  72 . For example, further rotation of the rotating shaft may cause the screw  96  to rotate about threads  98 , thereby driving the rotating shaft  80 , and the release device  74  in the upstream direction  90 , away from the downhole tool  72 . The threads  88  for electric decoupling and the threads  96  for mechanical decoupling may be disposed in opposite directions, which provides a layer of safety, because rotation of the rotating shaft  80  may cause the contact block  76  to rotate in a first direction that may cause the electric decoupling, and rotation of the rotating shaft  80  may cause the outer shell  84  to rotate in a second direction that may cause the mechanical decoupling. The opposite disposition of the threads enables an operator to have a higher degree of confidence that the electric decoupling is completed before beginning the mechanical decoupling. Although the present embodiment illustrates threaded connections and a rotating shaft causing the contact block  76  and the release device  72  to move in the upstream direction  90 , it should be appreciated that other mechanical systems may be used to cause the contact block  76 , the release device  72 , or both to move in the upstream direction  90 , such as a piston, a relay, a transistor, a pulley, etc. 
     In some embodiments, additional mechanical elements may be used to physically isolate the contact block  76 , the electric leads  94 , or both from the interior  86  of the wellbore  16  before the release device  74 ,  56 ,  58  mechanically decouples from the downhole tool  72 ,  50 ,  52 . For example, one or more covers may extend over the contact block  76 , the electric leads  94 , or both, such that when the release device  74  mechanically decouples from the downhole tool  72 , the contact block  76 , the electric leads  94 , or both remain in a cavity that is isolated from the interior  86  of the wellbore  16 . 
       FIG. 5  is a flowchart of an embodiment of a process  120  for electrically and mechanically decoupling a release device from a downhole tool. The process  120  enables the release device to decouple multiple electric leads of the downhole tool while maintaining a flow of electricity to other, upstream downhole tools. Although the following process  120  includes a number of operations that may be performed, it should be noted that the process  120  may be performed in a variety of suitable orders (e.g., the order that the operations are discussed, or any other suitable order). All of the operations of the process  120  may not be performed. Further, all of the operations of the process  120  may be performed by the motor controller, the data processing system, an operator, or a combination thereof. 
     The motor controller may receive (block  122 ) a signal indicative of a decoupling procedure. The signal may be sent by an operator, or the signal may be sent automatically. For example, a decoupling procedure may be part of a broader operation. As such, once the decoupling procedure part of the broader operation calls is reached, the signal indicative of the decoupling procedure may be sent. 
     Next, the motor controller causes the motor to drive the driveshaft into rotation, thereby causing the release device to electrically decouple (block  124 ) the release device from multiple electric leads of the downhole tool. As discussed above, a contact block contained within a cavity of the release device may move in an upstream direction, away from the downhole tool. This movement in the upstream direction may cause the contact block to decouple from multiple electric leads of the downhole tool, thereby electrically decoupling the release device from the downhole tool. 
     The motor controller causes the motor to drive the driveshaft into rotation, thereby causing the release device to mechanically decouple (block  126 ) the release device from the downhole tool. In the present embodiment, the motor controller causes the motor to drive the driveshaft, thereby causing the contact block to rotate in a first direction to electrically decouple the release device, and rotation of the driveshaft may also cause the outer shell to rotate in a second direction, opposite the first direction, to mechanically decouple the release device. As the release device is mechanically decoupled from the downhole tool, the electric leads come into contact with the interior of the wellbore, and the wellbore fluids contained within the interior of the wellbore. Because the electric leads have already been electrically decoupled, the contact between the electric leads and the wellbore fluids causes no electric hazards (e.g., electric shorts). As the contact block and electric leads come into contact with the interior of the wellbore, the pressure between the elements is equalized. 
     With the foregoing in mind, embodiments presented herein provide devices that are capable of electrically and mechanically decoupling from a downhole tool while maintain a flow of electricity through the toolstring. First, a device may electrically decouple from the downhole tool while remaining isolated from the wellbore fluids contained within the interior of the wellbore. Once the device is electrically decoupled, the device may mechanically decouple from the downhole tool. Maintaining a flow of electricity through the toolstring while releasing a downhole tool may reduce the time to pull the toolstring back to the surface, and may enable other downhole tools to continue operating. 
     The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.