Method for detecting bottom well faults in a well system, apparatus for detecting bottom well faults in a well system, and well system for hydrocarbon recovery.

Description

1 / 26 “METHOD FOR DETECTING BOTTOM WELL FAULTS IN A WELL SYSTEM, APPARATUS FOR DETECTING BOTTOM WELL FAULTS IN A WELL SYSTEM AND WELL SYSTEM FOR HYDROCARBON RECOVERY,” FIELD OF TECHNIQUE

[0001] The present invention relates generally to power services and, more specifically, to the detection of bottomhole faults in an electrical cable of a well system using spread spectrum time-domain reflectometry (SSTDR). BACKGROUND

[0002] In well systems, faults can occur in the well bottom, in the well cable, or in well devices connected to the well cable. Downhole faults can lead to reduced productivity in hydrocarbon exploration and recovery operations or, in some cases, a delay or interruption of hydrocarbon exploration and recovery operations. Time Domain Reflectometry (TDR) is sometimes used in the oil and gas industry for the detection of downhole faults in cables. However, TDR traces are often difficult to interpret and do not provide accurate results on the location of faults. Furthermore, TDR traces typically cannot be performed on a live cable as other signals may affect the TDR results, and therefore well systems are usually shut down to perform the TDR test. Shutting down well systems is expensive and results in unnecessary delays. BRIEF DESCRIPTION OF THE FIGURES Petition 870250086956, dated 09 / 25 / 2025, page 15 / 55 2 / 26

[0003] Figure 1 shows an exemplary diagram of a well system that includes a spread spectrum time domain reflectometer (SSTDR) for detecting downhole faults in a well electrical cable, according to some implementations.

[0004] Figures 2A and 2B are exemplary SSTDR traces that assist in detecting bottomhole faults, according to some implementations.

[0005] Figure 3 is a flowchart of exemplary operations for detecting bottomhole faults in a wellbore system, according to some implementations.

[0006] Figure 4 shows an exemplary computer system configured to implement SSTDR to detect bottomhole faults in a wellbore system, according to some implementations.

[0007] Figure 5 is a schematic diagram of a drilling rig system, as an example of oilfield services systems that use surface and downhole equipment, according to some implementations.

[0008] Figure 6 is a schematic diagram of an exemplary well system that includes fracturing operations, according to some implementations. DESCRIPTION

[0009] The following description includes exemplary EAs, methods, techniques, and program flows that describe aspects of the disclosure. However, it is understood that this disclosure can be practiced without these specific details. For example, this disclosure refers to reservoir modeling in illustrative examples. The Petition 870250086956, dated 09 / 25 / 2025, page 16 / 55 3 / 26 aspects of this disclosure can be applied to other types of models involving spatiotemporal datasets. In other cases, instances of well-known instructions, protocols, structures, and techniques have not been shown in detail to avoid confusion.

[0010] Time Domain Reflectometry (TDR) can be used in the oil and gas industry for downhole fault detection in well systems. However, TDR results are not accurate because they typically only pinpoint the location of the downhole fault within an area of ​​a few hundred meters. There may be multiple cable lines, downhole connectors, and well devices within a few hundred meters. Furthermore, TDR techniques for downhole fault detection typically cannot be performed on an active well system because other signals may affect the TDR results. Several innovative aspects of the subject matter described in this disclosure relate to downhole fault detection in well systems using spread spectrum time domain reflectometry (SSTDR).A well system SSTDR device can transmit an SSTDR signal to the bottom of the well via a well system electrical cable and receive a reflected SSTDR signal. The SSTDR device can determine if a fault exists in the well's electrical cable (such as a cable line or connector) or in a well device (such as a meter or sensor) based on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal, as described in more detail in this document. When a fault in the... Petition 870250086956, dated 09 / 25 / 2025, page 17 / 55 4 / 26 bottomhole fault detection: The SSTDR device can also determine the type of bottomhole fault and the location of the bottomhole fault, such as the bottomhole depth of the fault. Bottomhole fault detection in well systems using SSTDR can identify faults within a few centimeters or a fraction of an inch. Furthermore, SSTDR fault detection techniques can be performed on active well systems.

[0011] Figure 1 shows an exemplary diagram of a well system 100 that includes a spread spectrum time domain reflectometer (SSTDR) 110 for detecting bottomhole faults in a power cable 115. The SSTDR 110, the well power cable 115, the well 101 and the well equipment 105 can be used in various types of well systems for hydrocarbon exploration and recovery (such as oil and gas). One type of well system 100 may be a drilling rig system with well equipment 105 that is used for drilling, exploration and production operations, which is described in detail in Figure 5. Another type of well system 100 may be a fracturing system with well equipment 105 that is used for fracturing operations, as shown in Figure 6. The well system 100 may use the SSTDR device 110 for detecting faults in the bottom hole on the electrical cable 115.Figure 1 shows an example of an implementation of the SSTDR 110 device connected to a computer system 112. In some implementations, the SSTDR 110 device may be implemented as a standalone device or it may be... Petition 870250086956, dated 09 / 25 / 2025, page 18 / 55 5 / 26 implemented or installed on computer system 112.

[0012] As shown in Figure 1, the well electrical cable 115 is placed at the bottom of well 101 and connected to the SSTDR device 110. Various well devices, such as well devices 108A-F (which may generally be referred to as well devices 108), can be connected to the well electrical cable 115. The well electrical cable 115 can provide power and communication capabilities to the various well devices 108A-F. Well devices 108A-F can include any type of downhole device used in well systems, such as various types of downhole gauges, various types of downhole sensors, various types of downhole actuators, various types of downhole mandrels, and various types of downhole valves, among others.The 115 well electrical cable may also include various connectors or connection points, such as 111A-C downhole connectors (usually called 111 downhole connectors), which form the 115 well electrical cable and can be considered part of the overall 115 well electrical cable. 111A-C downhole connectors can be used to connect well devices (such as 108A-F well devices) to the well electrical cable, or they can be used to add additional cable lines or branches to the 115 well electrical cable. 111A-C connectors can be of various types of downhole electrical connectors, such as temperature and pressure resistant connectors and wet-fit connectors. The 115 well electrical cable may also include various cable lines, cable wires, cable branches, and various sections of the well electrical cable. Petition 870250086956, dated 09 / 25 / 2025, page 19 / 55 6 / 26 well 115 that are not shown in Figure 1 for simplicity. Note that Figure 1 shows an example of well 115 electrical cable from well 100 system, and in other examples, well systems may have well electrical cables with fewer or more well devices and in different locations within well 101. Note also that Figure 1 shows an exemplary well 115 electrical cable with some downhole connectors for simplicity, and in other examples, well systems may have several other connectors on various cable branches and in different locations within well 101.

[0013] In some implementations, the SSTDR 110 device may implement SSTDR to detect downhole faults in the well cable 115, including any faults in cable lines, connectors (such as well connectors 111), and well devices (such as well devices 108). The SSTDR 110 device may use SSTDR to detect the type of downhole fault and the location of the downhole fault. For example, types of downhole faults may include open circuits, short circuits, and other types of anomalies described further below. The location of a downhole fault may be, for example, a location in the well cable 115 at a given depth in the well.An SSTDR can monitor and locate changes in real time in energized electrical wires and circuits that may indicate faults, and therefore can be used to detect downhole faults in well electrical cables (such as well cable 115) of well systems (such as well system 100). The SSTDR... Petition 870250086956, dated 09 / 25 / 2025, page 20 / 55 7 / 26 can be used in operating electrical systems with minimal interference to signals already present in the system and to external sources of electrical noise, as SSTDR signals have natural immunity to noise. SSTDR signals also have a dynamic bandwidth in the frequency domain that can vary depending on the modulation frequency. Because SSTDR can be implemented on energized electrical wires, the SSTDR device 110 can be configured to continuously or periodically monitor the well cable 115 for downhole faults.

[0014] In some implementations, to detect the type and location of a bottomhole fault, the SSTDR 110 device may transmit one or more bottomhole SSTDR signals via the electrical cable 115. The SSTDR 110 device may receive one or more reflected SSTDR signals that are associated with the transmitted SSTDR signals. The SSTDR 110 device may correlate the reflected SSTDR signals with the transmitted SSTDR signals. The SSTDR 110 device may apply one or more signal processing or signal analysis algorithms (such as spread spectrum signal analysis algorithms) to the shape and timing of the signals to detect the location and type of bottomhole fault (such as short circuit or open circuit).Traditional TDR tracing results are typically neither accurate nor reliable, as they detect the location of a fault within a few hundred meters, and a cable may have multiple cable lines, connectors, and devices within those few hundred meters. SSTDR tracing results can... Petition 870250086956, dated 09 / 25 / 2025, p. 21 / 55 8 / 26 accurately detects the type of fault to within a few centimeters or a fraction of an inch. For example, an SSTDR trace might have a shape, such as that shown in Figure 2A, indicating that the bottomhole fault is an open circuit, and timing and other signal analysis might indicate that the bottomhole fault is at a depth of 7,581 feet (fraction of an inch accuracy). As another example, an SSTDR trace might have a shape, such as that shown in Figure 2B, indicating that the bottomhole fault is a short circuit, and timing and other signal analysis might indicate that the bottomhole fault is at a depth of 5,031 feet (fraction of an inch accuracy).Note that the signal shapes shown in Figures 2A and 2B are only examples and that the SSTDR 110 instrument can search for various other types of signal shapes or signal signatures, including more complex spread spectrum signal signatures, to detect a downhole fault and determine the type of downhole fault. Because the SSTDR can accurately locate the downhole fault to within a few centimeters or a fraction of an inch, the SSTDR 110 instrument can accurately identify whether the downhole fault is in a specific part of the cable line at the identified depth or in a specific well connector or device located at the identified depth. For example, in the examples described above, a well connector might be located at approximately 5,031 feet and a well device might be located at approximately 7,581 feet.

[0015] Bottomhole faults (such as short circuits) Petition 870250086956, dated 09 / 25 / 2025, p. 22 / 55 9 / 26 or open circuits) detected in a well device 108, in the downhole connector 111, or in the cable line can be caused by several reasons. For example, there may be a break in the cable line or connector, a faulty cable branch or connector, a break or weakness in a pipe box conductor, a faulty device, a disconnected device, or various other downhole faults. When a downhole fault is detected in one of the well devices 108, one of the components within the well device 108 may be faulty. In some implementations, in addition to having the capability to detect a faulty well device at a specific location in the downhole, the SSTDR 110 device may implement SSTDR to help detect which component (or components) of the various well device components is faulty.SSTDR can be used to aid in detecting downhole faults in well devices (such as 108-well devices) and components within well devices. For example, 108-well devices may include capacitors, diodes, resistors, solder connections, and various other types of internal connectors and components that may fail or be incorrectly installed. In some implementations, reflected SSTDR signals may have specific signal signatures that can identify which component has failed in a faulty well device. For example, as described below, machine learning algorithms and signal processing techniques can be used to identify a faulty well device and component. Petition 870250086956, dated 09 / 25 / 2025, page 23 / 55 10 / 26 defective inside the defective well device.

[0016] In some implementations, the SSTDR 110 device may implement machine learning algorithms and signal processing techniques (such as spread spectrum signal processing techniques) to help detect bottomhole faults in the well cable 115, including faults in cable lines, bottomhole connectors 111, well devices 108, and components within well devices 108. For example, the SSTDR 110 device may implement machine learning and spread spectrum signal processing and analysis techniques to help detect and analyze certain signal signatures in the reflected SSTDR signals that indicate at least one of the fault types, the type of well device that is faulty, or the component within a well device that is faulty.As another example, the machine learning algorithm can process and analyze SSTDR trace data, data from other measurement and troubleshooting techniques, and historical SSTDR and other historical troubleshooting data to detect bottomhole faults. In some implementations, machine learning and spread spectrum signal processing techniques may include acquiring and analyzing several different SSTDR traces from different SSTDR configurations, including transmitting SSTDR signals at different signal strengths, different spectrum configurations, or different signal types, among other configurations. In some implementations, the SSTDR 110 device may apply machine learning techniques. Petition 870250086956, dated 09 / 25 / 2025, page 24 / 55 11 / 26 machine and signal processing equipment to analyze historical and real-time data from one or more cables or conductors of the same well system (such as well system 100) and from several other well systems located locally or remotely. For example, the SSTDR apparatus 110 or the computer system 112 can connect to a cloud computer network or to remote servers that store historical SSTDR results from other local or remote well systems.Machine learning and spread spectrum signal analysis and processing techniques that utilize SSTDR tracking results, historical data, and data from other measurement and troubleshooting techniques can enable the detection of various types of downhole faults (beyond short circuits and open circuits) and anomalies, such as changes in circuit impedance, intermittent and persistent faults, reverse polarity, arc faults, and prediction of potential downhole faults, among others.

[0017] After identifying the location and type of fault, the SSTDR 110 device can determine which section or sections of the well's electrical cable 115, which downhole connectors 11, or which well devices 108 are failing most frequently. The SSTDR 110 device can analyze trends in downhole faults, predict possible future faults, and identify other patterns, for example, using machine learning algorithms. Well system operators 100 can determine the removal of certain connectors or well devices from the well system, find alternative connectors, well devices, or cables, or attempt to design around the Petition 870250086956, dated 09 / 25 / 2025, page 25 / 55 12 / 26 connectors or well devices in future well systems. In some cases, operators may remove and replace or repair the defective cable section, defective downhole connector, or defective well device. Operators may improve well system crew training or improve manufacturing processes for defective cables, connectors, or devices based on the results.

[0018] Figure 3 is a flowchart of exemplary operations for detecting downhole faults in a wellbore system. Operations may include transmitting a downhole SSTDR signal via a wellbore system power cable (block 310). Operations may include receiving, from the wellbore power cable, a reflected SSTDR signal associated with the transmitted SSTDR signal (block 320). Operations may include determining whether a downhole fault has been detected in the wellbore power cable or in at least one of several wellbore devices coupled to the wellbore power cable based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal (block 330).

[0019] In some implementations, in response to the detection of a bottomhole fault in the well electrical cable or in at least one of several well devices, operations may include determining a bottomhole fault location and a bottomhole fault type, where the bottomhole fault location may include a bottomhole depth of the bottomhole fault. In some implementations, the well electrical cable includes Petition 870250086956, dated 09 / 25 / 2025, page 26 / 55 13 / 26 cable lines and downhole connectors, and operations may include determining whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors, or in at least one of several devices based, at least in part, on the depth of the downhole fault and the type of downhole fault.

[0020] In some implementations, operations may include performing spread spectrum signal analysis on the reflected SSTDR signal and the transmitted SSTDR signal to determine real-time SSTDR data for the well system, accessing historical SSTDR data for the well system, accessing historical SSTDR data for one or more additional well systems, and determining whether a downhole fault is detected based, at least in part, on real-time SSTDR data for the well system, historical SSTDR data for the well system, and historical SSTDR data for one or more additional well systems.In some implementations, operations may include detecting a downhole fault in a first well device out of a plurality of well devices based, at least in part, on a downhole depth of the downhole fault and a downhole fault type, and determining which component out of a plurality of components of the first well device is faulty based, at least in part, on the downhole fault type and one or more signal signatures detected at least in the reflected SSTDR signal.

[0021] Figure 4 shows an example of a system of Petition 870250086956, dated 09 / 25 / 2025, page 27 / 55 14 / 26 computer configured to implement SSTDR to detect bottomhole faults in a wellbore system. In some implementations, computer system 400 may be an example of SSTDR apparatus 110 shown in Figure 1. In some implementations, computer system 400 may be an example of computer system 112 shown in Figure 1, which implements the functionality of SSTDR apparatus 110 or has SSTDR apparatus 110 installed in computer system 112, or works in conjunction with SSTDR apparatus 110 to implement SSTDR operations. Computer system 400 may include one or more processors 401 (possibly including multiple cores, multiple nodes and / or implementing multi-threading, etc.). Computer system 400 may include memory 407.Memory 407 can be system memory or any type or implementation of machine-readable or computer-readable media with instructions that are executed by one or more processors 401 to implement the operations described in Figure 1. The computer system 400 may also include a bus 403 and a network interface 405. The computer system 400 may also include a communications module 408 that can control wired and wireless communications, such as receiving data from sensors installed on well equipment and transmitting control information to control well equipment or devices. The computer system 400 may also include at least one SSTDR module 413 and a machine learning module 414, among other processing modules that perform the operations described in Figure 1. For example, the SSTDR module 413 may implement SSTDR for detection. Petition 870250086956, dated 09 / 25 / 2025, page 28 / 55 15 / 26 of bottomhole faults, as described in Figure 1. The machine learning module 414 can implement machine learning techniques and work in conjunction with the SSTDR module 413 to detect and analyze SSTDR traces and other SSTDR data in order to detect the type and location of bottomhole faults, as described in Figure 1. The functionality described herein can be implemented with an application-specific integrated circuit, in logic implemented in one or more 401 processors, in a coprocessor in a peripheral device or card, etc. Furthermore, implementations may include fewer components or additional components not illustrated in Figure 4 (e.g., video cards, audio cards, additional network interfaces, peripheral devices, etc.). One or more 401 processors and the 405 network interface can be coupled to the 403 bus.Although illustrated as being coupled to bus 403, memory 407 can be coupled to one or more processors 401.

[0022] Figure 5 is a schematic diagram of a drilling rig system, as an example of oilfield services systems that use surface and downhole equipment. For example, in Figure 5 it can be seen how a system 564 can also form a portion of a drilling rig 502 located on the surface 504 of a well. Oil and gas well drilling is commonly performed using a series of drill pipes connected together to form a drill string 508 which can be lowered via a rotary table 510 into a well or borehole 512. Petition 870250086956, dated 09 / 25 / 2025, page 29 / 55 16 / 26 Here, a drilling rig 586 can be fitted with a drilling tower 588 that supports a winch. A computer system 112 can be communicatively coupled to surface and downhole equipment, including the SSTDR apparatus 110 shown in Figure 1, which can be used for downhole fault detection. The computer system 112 can include memory (machine-readable media) and one or more processors, as described in Figure 4. A well cable 115 can be coupled to the SSTDR apparatus 110 in a manner similar to that described above with reference to Figure 1. Similar to Figure 1, the well cable 115 can include cable lines, downhole connectors, and well devices. The well cable 115 can provide power and communication capabilities to the well devices.As described in Figure 1, the SSTDR apparatus 110 can perform SSTDR operations to detect downhole faults in cable lines, downhole connectors, or well devices.

[0023] Drilling equipment 502 can provide support for the drill string 508. The drill string 508 can operate to penetrate the rotary table 510 to drill the well 512 through subsurface formations 514. The drill string 508 may include a Kelly 516, drill pipe 518, and a downhole assembly 520, possibly located in the lower portion of the drill pipe 518.

[0024] The downhole assembly 520 may include 522 controls, a downhole tool or attachment 524, and a drill bit 526. The drill bit Petition 870250086956, dated 09 / 25 / 2025, page 30 / 55 17 / 26 526 can operate to create a well 512 by penetrating the surface 504 and subsurface formations 514. The downhole equipment or tool 524 can comprise any of several different types of tools, including MWD tools, LWD tools, and others.

[0025] During drilling operations, the drill string 508 (perhaps including the Kelly 516, the drill pipe 518, and the downhole assembly 520) may be rotated by the rotary table 510. Additionally or alternatively, the downhole assembly 520 may also be rotated by a motor (e.g., a mud motor) which may be located at the bottom of the well. Commands 522 may be used to add weight to the drill bit 526. Commands 522 may also operate to stiffen the downhole assembly 520, enabling the downhole assembly 520 to transfer the added weight to the drill bit 526 and in turn assist the drill bit 526 in penetrating the surface 504 and subsurface formations 514.

[0026] Drilling operations may utilize various surface equipment, such as a mud pump 532 or other types of surface or downhole equipment. During drilling operations, the mud pump 532 may pump drilling fluid (sometimes known to those skilled in the art as “drilling mud”) from a mud well 534 through a hose 536 into the drill pipe 518 and down to the drill bit 526. The drilling fluid may flow out of the drill bit 526 and return to the surface 504 through Petition 870250086956, dated 09 / 25 / 2025, page 31 / 55 18 / 26 an annular area 540 between the drill pipe 518 and the sides of the borehole 512. The drilling fluid can then be returned to the mud well 534, where such fluid can be filtered. In some implementations, the drilling fluid can be used to cool the drill bit 526, as well as to provide lubrication for the drill bit 526 during drilling operations. Additionally, the drilling fluid can be used to remove cutouts from the underground formation 514 created by the operation of the drill bit 526. It may be images of these cutouts that many implementations operate to acquire and process.

[0027] Figure 6 is a schematic diagram of an exemplary well system that includes fracturing operations, according to some implementations. A well system 600 may include a well 604 in a subsurface formation 606. Well 604 may include a casing 602 and several boreholes 690A-690G drilled into casing 602 at different depths as part of hydraulic fracturing to allow hydraulic communication between the subsurface formation 606 and casing 602. Well system 600 may also include a computer system 112 that can be communicatively coupled to an SSTDR device 110 shown in Figure 1, which can be used for bottomhole fault detection. Computer system 112 may include memory (machine-readable or computer-readable media) and one or more processors, as described in Figure 4.The 600 well system may include a 115 well electrical cable that can be coupled to the 110 SSTDR apparatus in a manner similar to that described above with reference to Figure 1. In this way... Petition 870250086956, dated 09 / 25 / 2025, page 32 / 55 19 / 26 similar to Figure 1, the well cable 115 may include cable lines, downhole connectors, and well devices. The well cable 115 may provide power and communication capabilities to the well devices. As described in Figure 1, the SSTDR 110 device may perform SSTDR operations to detect downhole faults in cable lines, downhole connectors, or well devices.

[0028] Although aspects of the disclosure are described with reference to various implementations and exploitations, it will be understood that these aspects are illustrative and that the scope of the claims is not limited to them. In general, techniques for reservoir modeling, as described in this document, can be implemented with installations consistent with any hardware system or hardware systems. Many variations, modifications, additions, and improvements are possible.

[0029] Multiple examples may be provided for components, operations, or structures described herein as a single case. Finally, boundaries between various components, operations, and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are foreseen and may fall within the scope of the disclosure. In general, structures and functionalities presented as separate components in the example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be Petition 870250086956, dated 09 / 25 / 2025, page 33 / 55 20 / 26 implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure.

[0030] As used in this document, the term "or" is inclusive unless explicitly stated otherwise. Thus, the expression "at least one of A, B, or C" is satisfied by any element of the set {A, B, C} or any combination thereof, including multiples of any element. EXEMPLARY MODALITIES

[0031] Exemplary modalities may include the following:

[0032] Embodiment No. 1: A method for detecting bottomhole faults in a wellbore system comprising: transmitting a spread spectrum time-domain reflectometry (SSTDR) signal downhole via a wellbore system power cable; receiving, from the wellbore power cable, a reflected SSTDR signal associated with the transmitted SSTDR signal; and determining the detection of a bottomhole fault in the wellbore power cable or in at least one of several wellbore devices coupled to the wellbore power cable based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal.

[0033] Modality No. 2: The method of Modality No. 1, which further comprises: in response to the detection of a downhole fault in the well cable or in at least one of several well devices, determining a location of the downhole fault and a type of downhole fault, wherein the location of the downhole fault includes Petition 870250086956, dated 09 / 25 / 2025, p. 34 / 55 21 / 26 a depth at the bottom of the fault at the bottom of the well.

[0034] Mode No. 3: The method of Mode No. 2, wherein the well electrical cable includes cable lines and downhole connectors, which further comprises: determining whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors, or in at least one of several well devices based, at least in part, on the depth of the downhole fault and the type of downhole fault.

[0035] Mode No. 4: The method of Mode No. 1, which additionally comprises: correlating the reflected SSTDR signal with the transmitted SSTDR signal; and performing the signal analysis based, at least in part, on the correlation of the reflected SSTDR signal with the transmitted SSTDR signal.

[0036] Mode No. 5: The method of Mode No. 1, which additionally comprises: performing signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal using a machine learning algorithm.

[0037] Mode No. 6: The Mode No. 1 method which further comprises: performing spread spectrum signal analysis on the reflected SSTDR signal and the transmitted SSTDR signal to determine the real-time SSTDR data of the well system; accessing the historical SSTDR data of the well system; and determining whether a bottomhole fault has been detected based, at least in part, on the real-time SSTDR data and the historical SSTDR data of the well system. Petition 870250086956, dated 09 / 25 / 2025, page 35 / 55 22 / 26

[0038] Mode No. 7: The Mode No. 6 method, which further comprises: accessing historical SSTDR data from one or more additional well systems; and determining whether a bottomhole fault was detected based, at least in part, on real-time SSTDR data from the well system, historical SSTDR data from the well system, and historical SSTDR data from one or more additional well systems.

[0039] Embodiment No. 8: The method of Embodiment No. 1 which further comprises: detecting a bottomhole fault in a first well device of a plurality of well devices based at least in part on a bottomhole depth of the bottomhole fault and a type of bottomhole fault; and determining which component of a plurality of components of the first well device is defective based at least in part on the type of bottomhole fault and on one or more signal signatures detected at least in the reflected SSTDR signal.

[0040] Modality No. 9: An apparatus for detecting downhole faults in a wellbore system comprising: one or more processors; and a computer-readable media with stored instructions that are executable by the one or more processors to cause the apparatus to transmit a downhole SSTDR signal via a wellbore system electrical cable; receive, from the wellbore electrical cable, a reflected SSTDR signal associated with the transmitted SSTDR signal; and determine whether a downhole fault has been detected in the wellbore electrical cable or in at least one of several Petition 870250086956, dated 09 / 25 / 2025, page 36 / 55 23 / 26 well devices coupled to the well electrical cable based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal.

[0041] Mode No. 10: The Mode No. 9 apparatus, wherein the instructions also make the apparatus: in response to the detection of a bottomhole fault in the well cable or in at least one of several well devices, determine a location of the bottomhole fault and a type of bottomhole fault, wherein the location of the bottomhole fault includes a bottomhole depth of the bottomhole fault.

[0042] Mode No. 11: The apparatus of Mode No. 10, wherein the well cable includes cable lines and downhole connectors, and the instructions also make the apparatus: determine whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors, or in at least one of several well devices based, at least in part, on the depth of the downhole fault and the type of downhole fault.

[0043] Mode No. 12: The apparatus of Mode No. 9, in which the instructions also make the apparatus: correlate the reflected SSTDR signal with the transmitted SSTDR signal; and perform signal analysis based, at least in part, on the correlation of the reflected SSTDR signal with the transmitted SSTDR signal.

[0044] Mode No. 13: The device of Mode No. 9, in which the instructions still make the device: perform signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal using a machine learning algorithm. Petition 870250086956, dated 09 / 25 / 2025, page 37 / 55 24 / 26 machine.

[0045] Mode No. 14: The Mode No. 9 apparatus, in which the instructions also make the apparatus: perform analysis of the spread spectrum signal on the reflected SSTDR signal and the transmitted SSTDR signal to determine the real-time SSTDR data of the well system; access the historical SSTDR data of the well system; and determine whether a bottomhole fault has been detected based, at least in part, on the real-time SSTDR data and the historical SSTDR data of the well system.

[0046] Mode No. 15: The Mode No. 9 apparatus, wherein the instructions also make the apparatus: detect a bottomhole fault in a first well device of a plurality of well devices based at least in part on a bottomhole depth of the bottomhole fault and a type of bottomhole fault; and determine which component of a plurality of components of the first well device is defective based at least in part on the type of bottomhole fault and on one or more signal signatures detected at least in the reflected SSTDR signal.

[0047] Modality No. 16: A well system for hydrocarbon recovery comprising: a well electric cable; a plurality of well devices coupled to the well electric cable; and an SSTDR apparatus coupled to the well electric cable, wherein the SSTDR apparatus is configured to: transmit an SSTDR signal at the bottom of the well via a well electric cable; receive, from the well electric cable, a reflected SSTDR signal associated with the transmitted SSTDR signal; and Petition 870250086956, dated 09 / 25 / 2025, page 38 / 55 25 / 26 determine whether a bottomhole fault was detected in the well's electrical cable or in at least one of several well devices based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal.

[0048] Modality No. 17: The well system of Modality No. 16, wherein the SSTDR apparatus is further configured to: in response to the detection of a bottomhole fault in the well cable or in at least one of several well devices, determine a bottomhole fault location and a bottomhole fault type, wherein the bottomhole fault location includes a bottomhole depth of the bottomhole fault.

[0049] Modality No. 18: The well system of Modality No. 17, wherein the well electrical cable includes cable lines and downhole connectors, and the SSTDR apparatus is further configured to: determine whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors, or in at least one of several well devices based, at least in part, on the downhole depth of the downhole fault and the type of downhole fault.

[0050] Modality No. 19: The well system of Modality No. 16, in which the SSTDR apparatus is additionally configured to: perform spread spectrum signal analysis on the reflected SSTDR signal and the transmitted SSTDR signal to determine real-time SSTDR data for the well system; access historical SSTDR data for the well system; and determine whether a bottomhole fault is detected based, at least in part, on the Petition 870250086956, dated 09 / 25 / 2025, page 39 / 55 26 / 26 real-time SSTDR data and historical SSTDR data for the well system.

[0051] Modality No. 20: The well system of Modality No. 16, wherein the SSTDR apparatus is further configured to: detect a bottomhole fault in a first well device of a plurality of well devices based, at least in part, on a bottomhole depth of the bottomhole fault and a type of bottomhole fault; and determine which component of a plurality of components of the first well device is faulty based, at least in part, on the type of bottomhole fault and on one or more signal signatures detected at least in the reflected SSTDR signal. Petition 870250086956, dated 09 / 25 / 2025, pages 40 / 55

Claims

1 / 7 CLAIMS 1. A method for detecting bottomhole faults in a wellbore system, characterized in that it comprises: transmitting a spread spectrum time-domain reflectometry (SSTDR) signal to the bottomhole via an electrical cable of the wellbore system; receiving, from the wellbore electrical cable, a reflected SSTDR signal associated with the transmitted SSTDR signal; and determining whether a bottomhole fault has been detected in the wellbore electrical cable or in at least one of several wellbore devices coupled to the wellbore electrical cable based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal.

2. A method according to claim 1, characterized in that the well electrical cable includes cable lines and downhole connectors, which further comprises: in response to the detection of a downhole fault in the well electrical cable or in at least one of several well devices, determining a location of the downhole fault and a type of downhole fault, wherein the location of the downhole fault includes a bottomhole depth of the downhole fault and optionally determining whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors or in at least one of several well devices based at least in part on the bottomhole depth of the downhole fault and the type of downhole fault. Petition 870250088082, dated 09 / 29 / 2025, page 7 / 13 2 / 7 3. A method, according to any one of claims 1 or 2, characterized in that it further comprises: correlating the reflected SSTDR signal with the transmitted SSTDR signal; and performing the signal analysis based, at least in part, on the correlation of the reflected SSTDR signal with the transmitted SSTDR signal.

4. A method, according to any one of claims 1 to 3, characterized in that it further comprises: performing the analysis of the reflected SSTDR signal and the transmitted SSTDR signal using a machine learning algorithm.

5. A method according to any one of claims 1 to 4, characterized in that it further comprises: performing spread spectrum signal analysis on the reflected SSTDR signal and the transmitted SSTDR signal to determine real-time SSTDR data for the well system; accessing historical SSTDR data for the well system; optionally, accessing historical SSTDR data for one or more additional well systems; and determining whether a bottomhole fault is detected based, at least in part, on real-time SSTDR data, historical SSTDR data for the well system, and optionally, historical SSTDR data for one or more additional well systems.

6. Method, according to any of the claims 1 Petition 870250088082, dated 09 / 29 / 2025, pp. 8 / 13 3 / 7 to 5, characterized in that it further comprises: detecting a downhole fault in a first well device of a plurality of well devices based, at least in part, on a downhole depth of the downhole fault and on a type of downhole fault; and determining which component of a plurality of components of the first well device is defective based, at least in part, on the type of downhole fault and on one or more signal signatures detected at least in the reflected SSTDR signal.

7. Apparatus for detecting downhole faults in a wellbore system, characterized in that it comprises: one or more processors; and a computer-readable medium having instructions stored thereon that are executable by one or more processors to make the apparatus: transmit a spread spectrum time-domain reflectometry (SSTDR) signal at the bottom of the well via an electrical cable of the wellbore system; receive, from the wellbore electrical cable, a reflected SSTDR signal associated with the transmitted SSTDR signal; and determine whether a downhole fault has been detected in the wellbore electrical cable or in at least one of several wellbore devices coupled to the wellbore electrical cable based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal.

8. Apparatus according to claim 7, characterized in that the well cable includes lines of cables and downhole connectors, and the instructions also make the apparatus: in response to the detection of a downhole fault in the well cable or in at least one of the plurality of well devices, determine a location of the downhole fault and a type of downhole fault, wherein the location of the downhole fault includes a depth at the bottomhole of the downhole fault and optionally determine whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors or in at least one of the various well devices based at least in part on the depth at the bottomhole of the downhole fault and the type of downhole fault.

9. Apparatus, according to any one of claims 7 or 8, characterized in that the instructions further make the apparatus: correlate the reflected SSTDR signal with the transmitted SSTDR signal; and perform signal analysis based, at least in part, on the correlation of the reflected SSTDR signal with the transmitted SSTDR signal.

10. Apparatus, according to any one of claims 7 to 9, characterized in that the instructions further make the apparatus: perform signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal using a machine learning algorithm.

11. Apparatus, according to any of the claims in Petition 870250088082, dated 09 / 29 / 2025, pp. 10 / 13 5 / 7 7 to 10, characterized in that the instructions further make the apparatus: perform spread spectrum signal analysis on the reflected SSTDR signal and the transmitted SSTDR signal to determine real-time SSTDR data for the well system; access historical SSTDR data for the well system; and determine whether a bottomhole fault has been detected based, at least in part, on real-time SSTDR data and historical SSTDR data from the well system.

12. Apparatus, according to any one of claims 7 to 11, characterized in that the instructions further make the apparatus: detect a downhole fault in a first well device of a plurality of well devices based, at least in part, on a downhole depth of the downhole fault and on a type of downhole fault; and determine which component of a plurality of components of the first well device is defective based, at least in part, on the type of downhole fault and on one or more signal signatures detected in at least the reflected SSTDR signal.

13. Well system for hydrocarbon recovery, characterized in that: a well electrical cable; a plurality of well devices coupled to the well electrical cable; and a spread spectrum time domain reflectometry (SSTDR) apparatus coupled to the well electrical cable, wherein the SSTDR apparatus is configured to: transmit an SSTDR signal to the bottom of the well via a well electrical cable; receive, from the well electrical cable, a reflected SSTDR signal associated with the transmitted SSTDR signal; and determine whether a bottom-hole fault has been detected in the well electrical cable or in at least one of several well devices based, at least in part, on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal.

14. Well system according to claim 13, characterized in that the well electrical cable includes cable lines and downhole connectors, and wherein the SSTDR apparatus is additionally configured to: in response to the detection of a downhole fault in the well electrical cable or in at least one of the plurality of well devices, determine a location of the downhole fault and a type of downhole fault, wherein the location of the downhole fault includes a bottomhole depth of the downhole fault and optionally determine whether the downhole fault is in a section of the cable lines, in at least one of the downhole connectors or in at least one of several well devices based at least in part on the bottomhole depth of the downhole fault and the type of downhole fault.

15. Well system, according to any of claims 13 or 14, characterized in that Petition 870250088082, dated 09 / 29 / 2025, page.The 12 / 13 7 / 7 SSTDR device is additionally configured to: perform spread spectrum signal analysis on the reflected SSTDR signal and the transmitted SSTDR signal to determine real-time SSTDR data for the well system; access historical SSTDR data for the well system; determine if a downhole fault is detected based, at least in part, on real-time SSTDR data and historical SSTDR data of the well system; and optionally, detect the downhole fault in a first well device of a plurality of well devices based, at least in part, on the downhole depth of the downhole fault and on a type of downhole fault; and determine which component of a plurality of components of the first well device is defective based, at least in part, on the type of downhole fault and on one or more signal signatures detected in at least the reflected SSTDR signal.Petition 870250088082, dated 09 / 29 / 2025, p. 13 / 13.

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