Perforating gun string with repeater communication

Abstract

A communication unit may be used within a wellbore tool string in communication with a surface unit and comprising at least one downhole tool. The communication unit may include a housing defining a chamber therein and an electronics board disposed within the chamber. The electronics board comprising a processing circuit. The processing circuit may be configured to perform receiving an electronic signal from one of the surface unit and the at least one downhole tool, processing the electronic signal, and transmitting the processed electronic signal to the other of the surface unit and the at least one downhole tool.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 477,064 filed Dec. 23, 2022 and U.S. Provisional Patent Application No. 63 / 476,719 filed Dec. 22, 2022, the entire contents of each of which being incorporated by reference herein.BACKGROUND OF THE DISCLOSURE

[0002] Perforating gun strings may be configured for selective plug and perf systems. For example, a selective perforating gun string may be configured so that electrical signals (e.g., instructions) from the surface can pass through the perforating gun string to the selected perforating gun (which may, for example, be one of a plurality of perforating guns in the tool string) thereby selectively activating the selected perforating gun in the string (e.g., while not activating other perforating guns or tools at that time).

[0003] While this procedure is currently done, one or more potential problems have been observed in common selective downhole tool strings. For example, the electrical communication (e.g., signals) from the surface to the gun / tool string and the detonators therein can be strongly influenced by the cable and the electrical wiring between all detonators of a perforating gun sting. The signal for the lowest detonator must travel through the wireline cable and through all detonators up the string. Therefore, reading more complex data from sensors inside a detonator can be difficult. Accordingly, there is a need for an improved system for communicating electrical signals within a selective downhole tool string.

[0004] An exemplary embodiment of a method of wellbore communication may include providing a tool string. The tool string may include a communication unit and a wellbore tool. The method may further include providing a surface unit configured to control the tool string, deploying the wellbore tool in a wellbore using a wireline, transmitting, from one of the surface unit and the wellbore tool, an electronic signal to the communication unit, processing the electronic signal with the communication unit, and transmitting the processed electronic signal to the other of the surface unit and the wellbore tool.BRIEF DESCRIPTION

[0005] An exemplary embodiment of a communication unit may be used within a wellbore tool string in communication with a surface unit and comprising at least one downhole tool. The communication unit may include a housing defining a chamber therein and an electronics board disposed within the chamber. The electronics board comprising a processing circuit. The processing circuit may be configured to perform receiving an electronic signal from one of the surface unit and the at least one downhole tool, processing the electronic signal, and transmitting the processed electronic signal to the other of the surface unit and the at least one downhole tool.

[0006] An exemplary embodiment of a wellbore tool string may be in communication with a surface unit. The wellbore tool string may include a top connector configured to couple to a wireline, a communication unit comprising, a wellbore tool, and a tandem sub or tandem seal adapter coupled between the communication unit and the wellbore tool. The communication unit may include a housing defining a chamber therein, a top sub coupled to the housing at first end of the housing, a second end of the housing coupled to the top connector, and an electronics board disposed within the chamber. The electronics board may include a processing circuit. The communication unit may include a housing defining a chamber therein, an electronics board disposed within the chamber. The electronics board may include a processing circuit. The processing circuit may be configured to perform receiving an electronic signal from one of the surface unit and the at least one downhole tool, processing the electronic signal, and transmitting the processed electronic signal to the other of the surface unit and the at least one downhole tool.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more particular description will be rendered by reference to exemplary embodiments that are illustrated in the accompanying figures. Understanding that these drawings depict exemplary embodiments and do not limit the scope of this disclosure, the exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0008] FIG. 1 is a cross-sectional view of a communication unit assembly according to an embodiment;

[0009] FIG. 2 is a schematic cross-sectional view of at least a portion of an exemplary tool string including the communication unit assembly of FIG. 1, according to an embodiment;

[0010] FIG. 3A is a schematic block diagram of the operation of a communication unit according to an embodiment;

[0011] FIG. 3B is a schematic block diagram of the operation of a communication unit according to an embodiment;

[0012] FIG. 4 is a schematic block diagram of an electronics board according to an embodiment;

[0013] FIG. 5 is a flowchart showing an embodiment of a method for wellbore communication;

[0014] FIG. 6 is a schematic block diagram of an electronics board according to an embodiment;

[0015] FIG. 7 is a schematic block diagram of an electronics board according to an embodiment;

[0016] FIG. 8 is a graph showing an acceleration profile of a communication unit in three dimensions according to an embodiment;

[0017] FIG. 9 is a flowchart showing an embodiment of a method for shot detection in a wellbore; and FIG. 10 is a flowchart showing an embodiment of a method for detection of setting tool separation in a wellbore.

[0018] Various features, aspects, and advantages of the exemplary embodiments will become more apparent from the following detailed description, along with the accompanying drawings in which like numerals represent like components throughout the figures and detailed description. The various described features are not necessarily drawn to scale in the drawings but are drawn to aid in understanding the features of the exemplary embodiments.

[0019] The headings used herein are for organizational purposes only and are not meant to limit the scope of the disclosure or the claims. To facilitate understanding, reference numerals have been used, where possible, to designate like elements common to the figures.DETAILED DESCRIPTION

[0020] Reference will now be made in detail to various exemplary embodiments. Each example is provided by way of explanation and is not meant as a limitation and does not constitute a definition of all possible embodiments. It is understood that reference to a particular “exemplary embodiment” of, e.g., a structure, assembly, component, configuration, method, etc. includes exemplary embodiments of, e.g., the associated features, subcomponents, method steps, etc. forming a part of the “exemplary embodiment”.

[0021] For purposes of this disclosure, the phrases “devices,”“systems,” and “methods” may be used either individually or in any combination referring without limitation to disclosed components, grouping, arrangements, steps, functions, or processes.

[0022] An exemplary embodiment of a communication unit will now be introduced according to FIG. 1. The exemplary embodiment according to FIG. 1 is illustrative and not limiting, and exemplary features may be referenced throughout this disclosure.

[0023] Disclosed embodiments relate to a communication unit for use in a selective tool string (e.g., perforating gun string). The communication unit may be part of a tool string (e.g., perforating gun string) and be located above the perforating guns and possible release tool and setting tool (which may be located at the bottom of the tool string) of the tool string. In some embodiments, the surface unit (e.g., a computer) may communicate with the communication unit (for example, the surface unit may not directly communicate with tools downhole of the communication unit). The communication unit may be configured to receive signals / communication from the surface unit to forward / send / relay those signals to the perforating guns in the selective tool string (e.g., in accordance with the selective instructions). The communication unit may also be configured to receive signals / communication from the detonators and igniters of the various perforating guns in the tool string, and to send / relay (e.g., forwarding the signals from the detonators and igniters in the tool string) those signals to the surface unit. In some embodiments, the detonators and igniters of the various perforating guns in the tool string may only send signals to the communication unit and / or may not send signals to the surface unit directly. In some embodiments, the communication unit may effectively act as a signal amplifier / booster and / or repeater.

[0024] In some embodiments, initiators of the tool string will not only have the function to initiate the perforating gun (e.g., to ignite or activate shaped charges of the perforating guns), but also they can be equipped with one or more sensors, such as thermometers / temperature sensors, accelerometers, and / or inclinometers. The initiator may be a detonator, an igniter, or other similar device for initiating the perforating gun. Additional details on such exemplary initiators may be found in U.S. patent application Ser. No. 17 / 834,417 filed Jun. 7, 2022, which is commonly owned by DynaEnergetics Europe GmbH and hereby incorporated by reference herein to the extent not incompatible with the express disclosure herein.

[0025] In addition to providing improved signal communication (e.g., from the surface unit to the perforating guns of the tool string) independent from cable type, cable length, device count etc., one or more of the following parameters can be received by the communication unit from each initiator (e.g., which may each have the corresponding sensor therein): temperature, orientation, and acceleration (and therefore shock). In some embodiments, the communication unit can receive at least the following parameters from each initiator (e.g., which may each have the corresponding sensor therein): temperature, orientation, and acceleration (and therefore shock).

[0026] Additionally, the communication unit itself may have additional sensors. For example, the communication unit may include one or more pressure sensors (which may be configured to measure the wellbore pressure), thermometers, and / or accelerometers. The communication unit can also have the ability to measure the wellbore fluid temperature directly (at different depths), for example via channels in the top sub of the communication unit. This may provide useful information regarding the delta in temperature between the wellbore fluid and the temperature inside the detonator in a perforating gun assembly as part of the entire string.

[0027] The received data from the sensors of the communication unit itself and / or the perforating guns (e.g., the detonators or igniters) can be sent to the surface via wireline cable and enable real-time readings of the collected data (e.g., by the surface unit). The communication unit can receive signals (e.g., the firing signal for the selective initiators) from the surface (e.g., from the surface unit, via a wireline). These signals can be transmitted to the selected wellbore tools by the communication unit. In some embodiments, the electronics board of the communication unit may determine the selection (e.g., of the perforating gun to be activated) and transmit the signal accordingly. In some embodiments, the communication unit may be configured so that, in instances when the communication unit has a malfunction and it is shut off, the communication unit can have a feedthrough bypass, which allows selecting and shooting of the selective detonators in a conventional way from the surface fully independent of the communication unit (e.g., putting the surface unit directly into communication with the perforating guns of the tool string, while bypassing the faulty communications unit). For example, the communications unit may include a diagnostic process which may be configured to determine if the communication unit is faulty and / or whether the feedthrough bypass should be enabled. In some embodiments, the diagnostic process may be included on the electronics board of the communication unit (e.g., the electronics board may be configured to include the diagnostic process). In some embodiments, unless there is a detected malfunction in the communications unit, there may be no direct link between the tools below and the surface unit above.

[0028] In some embodiments, usage of the communications unit may also enable further safety functions of the perforating gun string. Possible examples are one or more of the following: programmable timers that allow firing of an initiator only in a specified time frame, or the firing signal can only transmit if a certain wellbore pressure is reached, which prevents unintended activation of one or more wellbore string tools. Also, measured acceleration can be used as a safety measure, as there should be no movement of the gun string for a certain time increment prior to initiation of a gun / tool. A combination of one or more safety measures based on measurements from the perforating guns (e.g. detonators) and / or in connection with measurement readings from the communications unit itself is also contemplated.

[0029] The sensors of the communication unit and tool string can also be used to confirm successful initiation of one or more wellbore tools. For example, a specific acceleration can be measured if a plug is set by a setting tool, and / or another (e.g., different) specific acceleration can be measured for a perforating gun or a release tool. In some embodiments, temperature readings can be used to confirm a successful initiation of a power charge of a setting tool or a release tool.

[0030] FIG. 2 illustrates exemplary communication ways / protocol / pathways (schematically shown as communication lines) within the perforating gun string by using the communication unit. As shown, the communications unit may be configured and placed in the tool string to receive all signals from the surface (towards the left) and communicate with the wireline tools below (e.g., boosting and / or forwarding / relaying the electronic signals from the surface unit to the wireline tools below). These can include a release tool, one or more perforating guns and optionally a setting tool. In some embodiments, all of the electronic communication / signals to the wellbore tools below may be from the electronics board of the communication unit. Similarly, the communications unit may be configured and placed in the tool string to receive all signals from the perforating guns / tools below and communicate with the surface unit (e.g. boosting and / or forwarding / relaying the electronic signals from the tools below to the surface unit above). Thus, the communication unit may serve as a communication hub between the surface unit above and the wellbore tools below. Typically, the electronics board may be configured to do more than merely pass-through electrical signals (e.g. in the conventional manner for selective tool string activation). For example, the electronic board may be configured to process the signal before sending it on (for example, making sure that the safety protocols based on sensed wellbore conditions indicate that firing is acceptable), amplify / boost the signal before sending it on, and / or filter the signal (e.g. to remove electronic noise) before sending it on.

[0031] Turning now to FIG. 1 in more detail, a communication unit assembly 101 is shown. In some embodiments, the communication unit assembly 101 may include a communication unit 105, a top connector 120, and a tandem sub 125. In some embodiments, the tandem sub 125 may be a tandem seal adapter. The top connector 120 may be coupled to the top of the communications unit 105 and the tandem sub 125 may be coupled to the bottom of the communication unit 105. The top connector 120 may be configured to pass electrical communication (e.g. electrical signals) from its top end to its bottom end (e.g. from a surface unit such as a computer via a wireline to the communication unit 105). The tandem sub 125 may have a bulkhead 126 extending therethrough, which may be configured to pass electrical communication (e.g. electrical signals) through the tandem sub 125 (e.g. from the communication unit 105 to the one or more wellbore tools below). In some embodiments, coupling of the top connector 120 and the tandem sub 125 to the communication unit 105 (e.g. on opposite ends) may be by complementary threading. In some embodiments, the top connector 120 may be configured to couple to a wireline, for example at its top end. In some embodiments, the tandem sun 125 may be configured to couple to a wellbore tool (such as a release tool or a perforating gun), for example at its bottom end.

[0032] As shown in FIG. 1, the communication unit 105 may include a housing 107 and an electronics board 110, which may include a processor or other processor unit. As used herein, processor may be any suitable processor (e.g., control circuit) adapted to perform the operations, calculations, and / or set of instructions described in the present disclosure including, but not limited to, a hardware processor, a field programmable gate array (FPGA), a digital signal processor (DSP), a central processing unit (CPU), a microprocessor, and combinations thereof. Those skilled in the art will appreciate that the processor may be substituted for by using any logic processor (e.g., control circuit) adapted to execute algorithms, calculations, and / or set of instructions described herein.

[0033] In some embodiments, the communication unit 105 may also include an energy storage component or other power source. For example, the energy storage component may be located on and / or be part of the electronics board 110 (e.g. the electronics board 110 may include an energy storage component). With the help of the energy storage component, the level of an incoming signal can be increased (e.g. amplified and / or boosted) before it is sent out (e.g. forwarded), which may be particularly useful when the signal level is very low due to losses on the wireline, for example. The electronics board 110 may be configured to use power from the energy storage component to amplify and / or boost an incoming signal, before then retransmitting (e.g. forwarding) the boosted signal onward to its final destination. If the incoming signal is received from the surface unit, then the boosted signal may be sent to one or more tools downhole. If the incoming signal is received from one or more of the tools of the tool string (e.g. disposed below the communications unit 105, as shown in FIG. 2 for example), then the boosted signal may be sent to the surface unit.

[0034] In some embodiments, the energy storage component may be a capacitor that can be charged in the borehole (e.g. downhole within the well) via the wireline before the signal communication begins. In some embodiments, the wireline may provide (e.g. separately, for example serially) (1) energy to charge the energy storage component and (2) electrical signals with instructions / communications. In some embodiments, the electronics board 110 may include a switch mechanism, operable to direct charging energy to the energy storage component and to direct electronic signals for amplification / boosting and / or onward transmission (e.g. forwarding). In some embodiments, the capacitor may be charged and / or recharged when the tool string (e.g. the communication unit 105) is downhole in the well. In some embodiments, the energy storage component can be a battery. For example, the energy storage component may be a rechargeable battery. In some embodiments, the battery may be recharged when the tool string (e.g. the communication unit 105) is downhole in the well. In some embodiments, the energy storage component can be a surface charged capacitor that provides energy for the duration of the operation downhole. For example, the surface charged capacitor may be fully charged prior to insertion of the communication unit 105 downhole, and that charge may be sufficient to operate the communication unit 105 for the duration of the downhole operation. In some embodiments, the energy storage component may include a plurality of power sources / component (e.g. a battery and a capacitor, multiple capacitors, multiple batteries, etc.).

[0035] FIG. 4 illustrates one possible embodiment of the electronics board 110. The electronics board may be in communication with a first signal line 232 connected at an uphole side and a second signal line 234 connected at a downhole side. The first signal line 232 may establish electrical communication between the electronics board 110 and the surface unit. The second signal line 234 may establish electrical communication between the electronics board 110 and a downhole wellbore tool 130. FIG. 4 schematically shows the first signal line 232 and the second signal line 234 as single lines, but it will be understood that the disclosure is not limited to this. For example, there may be two more separate lines (for example, lines dedicated to uphole transmission and downhole transmission) for each of the first signal line 232 and the second signal line 234.

[0036] The electronics board 110 may include an energy storage component 408, which may be any of the embodiments of energy storage component described in this disclosure. In an exemplary embodiment, the energy storage component 408 may be in electrical communication with the first signal line 232 to facilitate charging of the energy storage component 408 via the signal supplied by the first signal line 232. The electronics board 110 may also include a processing circuit 410. The processing circuit 410 may be powered by the energy storage component 408 and may include a processor 412 as described in this disclosure. The processing circuit 410 may be configured to receive an electronic signal from the surface unit via first signal line 232, process the electronic signal, and then transmit the processed electronic signal to the downhole wellbore tool 130 via the second signal line 234. Alternatively, the processing circuit 410 may be configured to receive an electronic signal from the downhole wellbore tool 130 via the second signal line 234, process the electronic signal, and then transmit the processed electronic signal to the surface unit via the first signal line 232. As described in this disclosure, the processing may include at least one of amplifying the electronic signal, filtering the electronic signal, or evaluating whether a predetermined wellbore condition is satisfied before relaying the signal.

[0037] In some embodiments, the housing 107 may have a chamber or cavity, and the electronics board 110 may be disposed in the chamber / cavity. In some embodiments, the chamber / cavity may be a through passage, extending longitudinally through the housing 107. In some embodiments, the top end of the chamber / cavity may be closed by a top sub 111, which may be coupled (e.g. with complementary threading) to the top end of the housing 107. The top sub 111 may include a bulkhead 113, which may extend through the top sub 111 and may be configured to pass electrical communication (e.g. electrical signals) therethrough. For example, the top sub may include a top sub housing and the bulkhead 113 may extend longitudinally through the top sub housing. In some embodiments, the bulkhead 113 may be disposed coaxially within the top sub housing (e.g. with the bulkhead 113 and the hollow top sub housing having a common longitudinal centerline axis). As shown in FIG. 1, the bulkhead 113 may be configured to provide electrical communication between the top connector 120 and the communications unit 105 (e.g. the electronic board 110 within the communication unit 105). In some embodiments, the bottom end of the chamber / cavity may be closed by the tandem sub 125, which may be coupled (e.g. with complementary threading) to the bottom end of the housing 107. As noted above, the tandem sub 125 may include bulkhead 126, which may extend through the tandem sub 125 and may be configured to pass electrical communication (e.g. electrical signals) therethrough. For example, the tandem sub 125 may include a tandem sub housing and the bulkhead 126 may extend longitudinally through the tandem sub housing. In some embodiments, the bulkhead 126 may be disposed coaxially within the tandem sub housing (e.g. with the bulkhead 126 and the hollow tandem sub housing having a common longitudinal centerline axis). In some embodiments, the bulkheads 113 and 126 may be similar, for example differing in dimension. Additional details on exemplary bulkheads may be found in U.S. Pat. No. 11,293,736 issued Apr. 5, 2022, and in U.S. patent application Ser. No. 17 / 677,478 filed Feb. 22, 2022, both of which are commonly owned by DynaEnergetics Europe GmbH and hereby incorporated by reference herein to the extent not incompatible with the express disclosure herein.

[0038] In some embodiments, the communication unit 105 may include one or more sensors, for example configured to measure one or more wellbore conditions. For example, in FIG. 1 the top sub 111 may include one or more pressure sensor 112, along with one or more channels 114 providing fluid communication between the exterior surface of the communication unit 105 (e.g. the external wellbore environment) and the pressure sensor 112.

[0039] The communication unit 105 may be configured to receive electrical signals / communication from the surface unit and to send electrical signals / communications to the wellbore tools in the tool string below. In some embodiments, the communication unit 105 may be configured to boost the electrical signals it receives from the surface unit and / or to forward / transmit the boosted electrical signals to the tool string below (e.g. for selective activation). For example, the electronics board 110 may use the energy storage component to boost / amplify the signal for transmission. In some embodiments, the communication unit 105 may be configured to receive electrical signals / communication from one or more of the wellbore tools of the tool string below. In some embodiments, the communication unit 105 may be configured to boost the electrical signals it receives from the one or more wellbore tools and to forward / transmit the boosted electrical signals to the surface unit. For example, the electronics board 110 may use the energy storage component to boost / amplify the signal for transmission. In some embodiments, the communication unit 105 may be configured to detect (e.g. by sensor) one or more wellbore conditions itself and to send a corresponding electrical signal to the surface unit.

[0040] In some embodiments, the electronics board 110 of the communication unit 105 may be in electrical contact with both the bulkhead 113 of the top sub 111 and the bulkhead 126 of the tandem sub 125. In some embodiments, the electronics board 110 may be configured to filter one or more signals, for example to remove electrical noise. In some embodiments, the electronics board 110 may communicate with the surface unit by transmitting signals through the bulkhead 113 and the top connector 120 (e.g. and therethrough to the surface unit, for example via a wireline). In some embodiments, the electronics board 110 may communicate with one or more wellbore tools downhole (e.g. to selectively control firing of specific perforating guns, which may allow for discharge in a specific order) by transmitting signals though the bulkhead 126 of the tandem sub 125. In some embodiments, the electronics board 110 may be disposed in the chamber between the top sub 111 and the tandem sub 125. In some embodiments, there may be no direct electrical connection or communication between the bulkhead 113 and the bulkhead 126 (e.g. all communication between the two bulkheads 113, 126 would pass through the electronics board 110 of the communication unit 105). In some embodiments, all communication between the two bulkheads 113, 126 would be boosted / amplified by the electronics board 110 (e.g. before forwarding the incoming signal to the other bulkhead). In some embodiments, unless there is a detected fault in the communication unit 105 (e.g. the electronics board 110), there may be no direct electrical connection or communication between the bulkhead 113 and the bulkhead 126; but If there is a detected fault in the communication unit 105 (e.g. electronics board 110), then the communication unit 105 may be configured to provide direct signal pass-through between bulkheads 113 and 126 (e.g. feedthrough bypass). For example, if there is no detected fault in the communication unit 105 (e.g. electronics board 110) then all signals between the two bulkheads 113, 126 may be amplified / boosted by the electronics board 110 (or alternatively, the electronics board 110 may boost those signals which are low); but if there is a detected fault in the communication unit 105 (e.g. the electronics board 110), then the signal may bypass the electronics board 110 and be directly transmitted between the bulkheads 113, 126 (e.g. without amplification).

[0041] The communication unit 105 may also enable further safety functions of the perforating gun string. For example, the electronic board 110 of the communication unit 105 may include programmable timers, that allow firing of an initiator only in a specified time frame and / or the electronics board 110 may be configured so that the firing signal (e.g. to the wellbore tools below) can only transmit if a certain wellbore pressure is reached (e.g. as sensed by the pressure sensor 112 of the communication unit, and / or by one or more of the wellbore tools), which prevents unintended activation of one or more wellbore string tools. Also, the electronics board 110 may be configured so that acceleration (e.g. as measured by sensors on the communication unit 105 and / or the one or more wellbore tools) can be used as a safety measure, for example, requiring a predetermined period of time with no movement of the one or more wellbore tools before initiation.

[0042] FIG. 2 illustrates an exemplary tool string 200 having the communication unit 105, a release tool 210, one or more perforating gun 220a-d, and a setting tool 230. It should be understood that some tool strings may not have some of these specific tools and / or may have other or additional tools. In some embodiments, all communication may through the communication unit 105. In some embodiments, electrical signals from the surface unit (not shown) are only received by the communication unit 105 (e.g. there is no direct communication between the wellbore tools of the tool string and the surface unit). In some embodiments, electrical signals from the one or more wellbore tools may only be received by the communication unit 105 (e.g. there is no direct communication between the wellbore tools and the surface unit). For example, signals from the surface may be received by the communication unit 105, processed by the electronic board 110 of the communication unit 105 (e.g. amplified or boosted), and relayed to the appropriate wellbore tool (e.g. by transmission of the signal though the bulkhead 126 of the tandem sub and therethrough to the wellbore tools). Transmission of the signals through the wellbore tools of the tool string may occur in standard fashion, for example with each wellbore tool configured to process the electrical signal and determine if the selective instruction relates to that tool or should be transmitted on down the line.

[0043] In some embodiments, the communication unit 105 may be configured so that, in instances when the communication unit 105 has a malfunction and / or is shut off, the communication unit 105 can have a feedthrough bypass 238 as seen in FIG. 2, which allows selecting and shooting the selective detonators in a conventional way from the surface fully independent of the communication unit 105 (e.g. putting the surface unit directly into communication with the tools / perforating guns of the tool string, while bypassing the faulty communications unit 105). In some embodiments, such a feedthrough bypass (e.g. signal transmission via wire through the communication unit 105 to place the surface unit into direct contact with the wellbore tools below, for example without any processing, amplification, or boosting by the communication unit 105) would only be available in instances when it has been determined that the communication unit 105 is faulty.

[0044] FIG. 3A shows one possible embodiment in which the processing circuit of the communication unit 105 is functioning normally, i.e., in an operable state. In this case, a raw signal is supplied to the communication unit 105 via the first signal line 232. Because the processing unit of the communication unit 105 is functioning normally, the communication unit 105 is configured to block communication via the feedthrough bypass 238. This is schematically indicated by the broken line of feedthrough bypass 238 in FIG. 3A. Instead, the raw signal is processed by the communication unit 105 and output as a processed signal to the second signal line 234.

[0045] FIG. 3B shows one possible embodiment in which the processing circuit of the communication unit 105 is functioning abnormally and / or is in an inoperable state. In this case, the communication unit 105 may be configured to enable communication directly between the first signal line 232 and the second signal line 234 via the feedthrough bypass 238. For example, the raw signal supplied via the first signal line 232 may be directly communicated to the feedthrough bypass 238 without processing, ultimately being communicated to the second signal line 234. This will allow the tool string to retain at least some functionality even if the communication unit 105 is not fully operable.

[0046] FIG. 5 shows one possible embodiment of a method 500 for wellbore communication. In block 500, a tool string is provided. The tool string may include a communication unit and a wellbore tool in accordance with any of the embodiments described herein. In block 504, a surface unit is provided. In block 506, the tool string is deployed to a wellbore. In block 508, an electronic signal is transmitted. The electronic signal may be transmitted from either of the surface unit or the wellbore tool. In block 510, the electronic signal is received by the communication unit and processed according to its configuration. In block 512 the processed signal is transmitted to the other surface unit and the wellbore tool, i.e., whichever component did not originate the electronic signal.

[0047] FIG. 6 shows one possible embodiment of an electronics board 110 that may be used for shot detection, i.e., detecting when a tool (including, but not limited to, perforating guns, plugs, setting tools, punch tools, cutting tools) in the tool string has been initiated. This can provide real-time confirmation to the wellsite operator that the perforating guns have fired. This may enhance worksite safety because the operator will know that the perforating guns have fired before retrieving the tool string from the well. In other words, the operator can know that there are no longer any armed perforating guns being retrieved from the well.

[0048] FIG. 6 shows that the pressure sensor 112 may be operably coupled to the processing circuit 410 of the electronics board. In an alternative embodiment, the pressure sensor 112 may be a combined temperature / pressure sensor. As shown in FIG. 1, the pressure sensor 112 may be in fluid communication with the wellbore and configured to measure a pressure of the wellbore. The pressure sensor 112 may be configured to send a signal indicative of the wellbore pressure to the processing circuit 410. In an exemplary embodiment, the electronics board 110 may further include a non-transitory memory 616 that includes computer-executable instructions, that, when executed by the processor 412, cause the processor to evaluate whether the pressure in the wellbore exceeds a predetermined pressure threshold. The processor 412 may further determine that a perforating gun has been fired in response to the wellbore pressure exceeding the predetermined pressure threshold. Additionally, the processor 412 may be configured to determine whether the wellbore pressure exceeds the predetermined pressure threshold for a predetermined duration. If the wellbore pressure exceeds the predetermined pressure threshold for the predetermined duration, then the processor 412 may determine that the that a perforating gun has been fired. The predetermined pressure threshold and predetermined duration may be set and / or programmed by an operator based on factors including, but not limited to, type of wellbore fluid being used, ambient pressure of the wellbore fluid, depth of the wellbore, the surrounding rock formation, diameter of the wellbore, number of charges being fired in the perforating gun, size of the charges being fired in the perforating gun, and alignment of the charges being fired in the perforating gun. The processing circuit 410 may be configured to send a signal to the surface unit via the first signal line 232 indicating whether a perforating gun has been fired.

[0049] FIG. 6 shows that the pressure sensor 112 sends a signal to the processing circuit 410 of the electronics board 110. In an alternative embodiment the pressure sensor 112 may send a signal to a different circuit on the electronics board separate from the processing circuit 410 for the shot detection determination. In another alternative embodiment, a separate electronics board dedicated to shot detection may be provided in addition to the electronics board 110, and the pressure sensor 112 may be connected to this separate electronics board.

[0050] The embodiment shown in FIG. 6 shows that the shot detection determination is done at the processing circuit 410 of the electronics board 110, i.e., in the communication unit 105 that is deployed in the wellbore. In an alternative embodiment, the processing circuit 410 may be configured to transmit the signal from the pressure sensor 112 to the surface unit, and the shot detection evaluation may be made at the surface unit instead of the processing circuit 410. In an exemplary embodiment, the processing circuit 410 may process the signal from the pressure sensor 112 before sending it to the surface unit. Such processing may include amplifying or filtering the signal from the pressure sensor 112.

[0051] FIG. 7 shows one possible embodiment of an electronics board 110 that may be used for detection of separation of the setting tool 230 from the tool string 200. As seen in FIG. 7, the electronics board 110 may include a g-sensor 718. The g-sensor 718 may be configured to detect changes in acceleration of the communication unit 105. In an exemplary embodiment, the g-sensor 718 may include one or more of an accelerometer, inclinometer, and / or a gyroscope. The g-sensor may be operably connected to the processing circuit 410. The g-sensor 718 may be configured to send a signal indicative of acceleration and / or change in acceleration to the processing circuit 410. The acceleration may be measured in one or more dimensions. In an exemplary embodiment, the acceleration measured by the g-sensor 718 may be measured in three orthogonal directions (for example, along an x-axis, a y-axis, and a z-axis). In an exemplary embodiment, the electronics board 110 may further include the non-transitory memory 616 that includes computer executable instructions, that, when executed by the processor 412, cause the processor to track the acceleration data provided by the g-sensor 718 and determine when certain acceleration conditions are satisfied.

[0052] For example, separation of the setting tool 230 may result in a certain movement and acceleration of the connected tool string 200, including the communication unit 105. This movement and acceleration will be recorded by the g-sensor. An operator can determine the acceleration profile of the communication unit 105 when the setting tool 230 is separated under given wellbore conditions and program the non-transitory memory 616 and / or the processing circuit 410 to detect such an acceleration profile. FIG. 8 shows one possible embodiment of an acceleration profile in three dimensions following separation of the setting tool 230. Conditions of the acceleration profile that may be evaluated to determine whether the setting tool 230 has separated may include, but are not limited to: amplitude of acceleration in one or more dimensions, time duration above or below an acceleration threshold in or more dimensions, number of peaks or troughs above or below an acceleration threshold in a given period of time, frequency of the acceleration in one or more dimensions, or amplitude of frequency components of the acceleration in one or more dimensions (possibly calculated through a Fourier transform or fast Fourier transform, for example). If it is determined that the acceleration profile satisfies the predetermined conditions, then the processing circuit 410 can make a determination that the setting tool 230 has separated from the tool string 200. The processing circuit 410 may be configured to send a signal to the surface unit via the first signal line 232 indicating whether the setting tool 230 has been separated.

[0053] The embodiment described above with respect to FIG. 7 envisions that the setting tool separation determination is done at the processing circuit 410 of the electronics board 110, i.e., in the communication unit 105 that is deployed in the wellbore. In an alternative embodiment, the processing circuit 410 may be configured to transmit the signal from the g-sensor 718 to the surface unit, and the setting tool separation determination may be made at the surface unit instead of the processing circuit 410. In an exemplary embodiment, the processing circuit 410 may process the signal from the g-sensor 718 before sending it to the surface unit. Such processing may include amplifying or filtering the signal from the g-sensor 718.

[0054] The embodiment described above with respect to FIG. 7 uses acceleration to determine whether a setting tool has been separated. The acceleration measured by the g-sensor 718 can also be used for shot detection. As described above, a predetermined acceleration profile can be determined for separation of the setting tool. Similarly, a predetermined acceleration profile can be determined for firing of a perforating gun, based on charge size, number of charges, alignment of charges, and / or wellbore environmental factors. Thus, instead of evaluating measured acceleration against the setting tool predetermined acceleration profile, the measured acceleration can be measured against the predetermined perforating gun acceleration profile to determine if a shot was fired.

[0055] FIG. 9 illustrates one possible embodiment of a method 900 for performing shot detection in a wellbore. In block 902, a tool string is deployed to a wellbore. The tool string may include at least one wellbore tool (such as, but not limited to, a perforating gun, setting tool, plug tool, punch tool, cutting tool) and a pressure sensor in fluid communication with the wellbore, such as the pressure sensor 112 described above with reference to FIG. 1. In block 904, a firing signal is sent to the at least one wellbore tool. In block 906, following the firing signal, a wellbore pressure is measured using the pressure sensor. The pressure may be continuously monitored or may be programmed to be measured for a predetermined amount of time before and / or after the firing signal is relayed to the wellbore tool. In block 908, it is determined whether the measured wellbore pressure exceeds a predetermined threshold. If the wellbore pressure does not exceed the predetermined threshold (i.e., “No” in block 908), the method proceeds to block 910 where it is concluded that no shot was detected. If the wellbore pressure does exceed the predetermined threshold (i.e., “Yes” in block 908), the method proceeds to block 912. In an alternative embodiment, if it is determined in block 908 that the pressure exceeds the threshold, this may be sufficient to conclude that a shot has been detected. In block 912, it is determined whether the wellbore pressure exceeds the pressure threshold for a predetermined amount of time, i.e., a duration threshold. If the duration threshold is not satisfied (i.e., “No” in block 912), the method proceeds to block 914 where it is concluded that no shot was detected. If the duration threshold is satisfied (i.e., “Yes” in block 912), then the method proceeds to block 916 where it is determined that a shot was detected.

[0056] FIG. 10 illustrates one possible embodiment of a method 1000 for detecting whether a setting tool has separated from a tool string. In block 1002, a tool string is deployed to a wellbore, the tool string may include a setting tool and a g-sensor provided on the rest of the tool string other than the setting tool. The g-sensor may be the g-sensor 718 described above with reference to FIG. 7. In block 1004 a signal is sent to cause separation of the setting tool from the tool string. In block 1006, following the separation signal, an acceleration of the tool string is measured by the g-sensor. The acceleration may be continuously monitored or may be programmed to be measured for a predetermined amount of time before and / or after the separation signal is relayed to the setting tool. In block 1008 it is determined whether the measured acceleration matches a predetermined acceleration profile. The predetermined acceleration profile may include one or more conditions of the acceleration in one or more dimensions as described above with reference to FIG. 7. If it is determined that the measured acceleration does not match the predetermined profile (i.e., “No” in block 1008), then the method proceeds to block 1010 where it is determined that the setting tool did not separate. If it is determined that the measured acceleration does match the predetermined profile (i.e., “Yes” in block 1012), then the method proceeds to block 1012 where it is determined that the setting tool did separate.

[0057] This disclosure, in various embodiments, configurations and aspects, includes components, methods, processes, systems, and / or apparatuses as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. This disclosure contemplates, in various embodiments, configurations and aspects, the actual or optional use or inclusion of, e.g., components or processes as may be well-known or understood in the art and consistent with this disclosure though not depicted and / or described herein.

[0058] The phrases “at least one”, “one or more”, and “and / or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and / or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.

[0059] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” or “approximately” is not to be limited to the precise value specified. Such approximating language may refer to the specific value and / or may include a range of values that may have the same impact or effect as understood by persons of ordinary skill in the art field. For example, approximating language may include a range of + / −10%, + / −5%, or + / −3%. The term “substantially” as used herein is used in the common way understood by persons of skill in the art field with regard to patents, and may in some instances function as approximating language. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value.

[0060] In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The terms “a” (or “an”) and “the” refer to one or more of that entity, thereby including plural referents unless the context clearly dictates otherwise. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. Furthermore, references to “one embodiment”, “some embodiments”, “an embodiment” and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Terms such as “first,”“second,”“upper,”“lower” etc. are used to identify one element from another, and unless otherwise specified are not meant to refer to a particular order or number of elements.

[0061] As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and / or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur-this distinction is captured by the terms “may” and “may be.”

[0062] As used in the claims, the word “comprises” and its grammatical variants logically also subtend and include phrases of varying and differing extent such as for example, but not limited thereto, “consisting essentially of” and “consisting of.” Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that the appended claims should cover variations in the ranges except where this disclosure makes clear the use of a particular range in certain embodiments.

[0063] The terms “determine”, “calculate” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.

[0064] This disclosure is presented for purposes of illustration and description. This disclosure is not limited to the form or forms disclosed herein. In the Detailed Description of this disclosure, for example, various features of some exemplary embodiments are grouped together to representatively describe those and other contemplated embodiments, configurations, and aspects, to the extent that including in this disclosure a description of every potential embodiment, variant, and combination of features is not feasible. Thus, the features of the disclosed embodiments, configurations, and aspects may be combined in alternate embodiments, configurations, and aspects not expressly discussed above. For example, the features recited in the following claims lie in less than all features of a single disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

[0065] Advances in science and technology may provide variations that are not necessarily express in the terminology of this disclosure although the claims would not necessarily exclude these variations.

Claims

1. A communication unit for use within a wellbore tool string in communication with a surface unit and comprising at least one downhole tool, the communication unit comprising:a housing defining a chamber therein;an electronics board disposed within the chamber, the electronics board comprising a processing circuit;a first signal line configured to provide electronic communication between the surface unit and the electronics board;a second signal line configured to provide electronic communication between the electronics board and the at least one downhole tool; anda feedthrough bypass configured to provide direct electronic communication between the first signal line and the second signal line;wherein the processing circuit is configured to perform:receiving an electronic signal from one of the surface unit and the at least one downhole tool, processing the electronic signal, and transmitting the processed electronic signal to the other of the surface unit and the at least one downhole tool.

2. The communication unit of claim 1, wherein the processing the electronic signal with the communication unit comprises at least one of amplifying the electronic signal, filtering the electronic signal, or evaluating whether a predetermined wellbore condition is satisfied.

3. (canceled)4. The communication unit of claim 1, wherein the processing circuit is configured such that:electronic communication between the first signal line and the second signal line via the feedthrough bypass is blocked in response to a determination that the processing circuit is in an operable state, andelectronic communication via between the first signal line and the second signal line via the feedthrough bypass is enabled in response to a determination that the processing circuit is in an inoperable state.

5. The communication unit of claim 1, wherein the processing circuit comprises a processor.

6. The communication unit of claim 1, wherein the electronics board further comprises an energy storage component configured to supply power to the processing circuit.

7. The communication unit of claim 1, further comprising a top sub coupled to the housing at a first end of the housing.

8. The communication unit of claim 7, wherein the top sub further comprises a pressure sensor in fluid communication with the wellbore.

9. A wellbore tool string in communication with a surface unit, the wellbore tool string comprising:a top connector configured to couple to a wireline;a communication unit;a wellbore tool; anda tandem sub or tandem seal adapter coupled between the communication unit and the wellbore tool;wherein the communication unit comprises:a housing defining a chamber therein;an electronics board disposed within the chamber, the electronics board comprising a processing circuit;a first signal line configured to provide electronic communication between the surface unit and the electronics board;a second signal line configured to provide electronic communication between the electronics board and the at least one downhole tool; anda feedthrough bypass configured to provide direct electronic communication between the first signal line and the second signal line:wherein the processing circuit is configured to perform:receiving an electronic signal from one of the surface unit and the at least one downhole tool, processing the electronic signal, and transmitting the processed electronic signal to the other of the surface unit and the at least one downhole tool.

10. The wellbore tool string of claim 9, wherein the processing the electronic signal with the communication unit comprises at least one of amplifying the electronic signal, filtering the electronic signal, or evaluating whether a predetermined wellbore condition is satisfied.

11. (canceled)12. The wellbore tool string of claim 9, wherein the processing circuit is configured such that:electronic communication between the first signal line and the second signal line via the feedthrough bypass is blocked in response to a determination that the processing circuit is in an operable state, andelectronic communication via between the first signal line and the second signal line via the feedthrough bypass is enabled in response to a determination that the processing circuit is in an inoperable state.

13. The wellbore tool string of claim 9, wherein the processing circuit comprises a processor.

14. The wellbore tool string of claim 9, wherein the electronics board further comprises an energy storage component configured to supply power to the processing circuit.

15. The wellbore tool string of claim 14, wherein the top sub further comprises a pressure sensor or a temperature sensor in fluid communication with the wellbore.

16. A method of wellbore communication, the method comprising:providing a tool string comprising:a communication unit; anda wellbore tool;providing a surface unit configured to control the tool string;deploying the wellbore tool in a wellbore using a wireline;transmitting, from one of the surface unit and the wellbore tool, an electronic signal to the communication unit;processing the electronic signal with the communication unit; andtransmitting the processed electronic signal to the other of the surface unit and the wellbore tool;wherein the communication unit comprises:a housing defining a chamber therein;an electronics board disposed within the chamber, the electronics board comprising a processing circuit;a first signal line configured to provide electronic communication between the surface unit and the electronics board;a second signal line configured to provide electronic communication between the electronics board and the wellbore tool; anda feedthrough bypass configured to provide direct electronic communication between the first signal line and the second signal line; andwherein the method further comprises:blocking electronic communication between the first signal line and the second signal line via the feedthrough bypass in response to a determination that the processing circuit is in an operable state, andenabling electronic communication between the first signal line and the second signal line via the feedthrough bypass in response to a determination that the processing circuit is in an inoperable state.

17. The method of claim 16, wherein the processing the electronic signal with the communication unit comprises at least one of amplifying the electronic signal, filtering the electronic signal, or evaluating whether a predetermined wellbore condition is satisfied.

18. (canceled)19. The method of claim 16, wherein the electronics board further comprises an energy storage component configured to supply power to the processing circuit.

20. The method of claim 19, further comprising charging the energy storage component with electrical power via the first signal line.

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