Downhole tool sensor guard

Abstract

A system for covering sensitive components in a downhole string includes a junction segment in the downhole string, the junction segment including a longitudinal axis and a reduced diameter portion along the longitudinal axis. The system also includes a guard element disposed on the reduced diameter portion. The system further includes a mounting system adapted to axially couple the guard element to the junction segment. The mounting system includes a pocket in one of the junction segment and the guard element, the pocket including a shoulder. The mounting system also includes a threaded bore in the other of the junction segment and the guard element, the threaded bore oriented at least partially parallel to the longitudinal axis of the junction segment. The mounting system further includes a fastener that engages the threaded bore through the pocket and axially couples the guard element to the junction segment.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Patent Application No. 17 / 478,340, entitled “Downhole Tool Sensor Guard,” filed September 17, 2021, and priority to U.S. Provisional Patent Application No. 63 / 080,099, entitled “Downhole Tool Sensor Guard,” filed September 18, 2020, the entire disclosure of which is incorporated herein by reference. Background Technology Technical Field

[0003] This disclosure relates to systems and methods for protecting or covering at least a portion of a downhole tool. Specifically, this disclosure relates to removable protective elements for components disposed on a downhole tool.

[0004] 2. Related Art

[0005] Oil and gas extraction can involve downhole measurement operations, where various sensors are used to collect data to determine one or more wellbore characteristics. These sensors may include one or more antennas for transmitting and / or receiving information. These antennas are subjected to wellbore pressure, wellbore temperature, fluid flow conditions, and potential contact with structures within the wellbore, such as the wellbore wall. Tools may include plates or caps to protect the antennas. The cap must be securely attached to the tool. The connection between the cap and the cap often provides a stress location along the tool string and, due to their design, may be prone to breakage. Summary of the Invention

[0006] The applicant recognizes the limitations of existing systems herein and, based on this disclosure, conceives and develops implementation schemes for systems and methods for improving sensor covers.

[0007] In one embodiment, a system for covering a sensor component includes a connector section comprising a reduced-diameter portion and a protective element disposed on the reduced-diameter portion. The system also includes a mounting system adapted to axially engage the protective element to the connector section. The mounting system includes a locking element positioned in a recess formed in the connector section, the locking element being engaged with the protective element. The mounting system further includes a fastener extending through the locking element to engage the protective element. The mounting system also includes an orifice formed through the recess, the orifice engaging the reduced-diameter portion to the recess, wherein at least a portion of the locking element extends through the orifice.

[0008] In one embodiment, a system for covering a sensor component includes a nipple section. The system further includes a mounting section formed in a reduced diameter portion of the nipple section, the mounting section including a plurality of slots separated by a wall. The system includes a first housing segment including a pocket formed in a surface of the first housing segment. The system further includes a second housing segment. The system includes a fastener positioned within the pocket and coupling the first housing segment to the second housing segment, the fastener extending through one of the plurality of slots, the fastener engaging an aperture formed in the second housing segment.

[0009] In one embodiment, a system for covering a sensor component includes a nipple. The system includes a reduced diameter portion between a first nipple section and a second nipple section and a pocket formed in the first nipple section proximate the reduced diameter portion, the pocket having an aperture extending through the first nipple section toward the reduced diameter portion. The system further includes a guard element positioned within the reduced diameter section, the guard element coupled to the nipple, and a mounting system joining the guard element to the nipple. The mounting system includes a locking element adapted to extend at least partially through the aperture, the locking element positioned within the pocket, and a fastener extending through the locking element and engaging a first end of the guard element, wherein a fastener axis is substantially parallel to a sub-axis.

[0010] In one embodiment, a system for covering a sensitive component in a downhole string includes a nipple section in the downhole string, the nipple section including a longitudinal axis and a reduced diameter portion along the longitudinal axis. The system further includes a guard element disposed on the reduced diameter portion. The system further includes a mounting system adapted to axially couple the guard element to the nipple section. The mounting system includes a pocket in one of the nipple section and the guard element, the pocket including a shoulder. The mounting system further includes a threaded bore in the other of the nipple section and the guard element, the threaded bore oriented at least partially parallel to the longitudinal axis of the nipple section. The mounting system further includes a fastener engaging the threaded bore through the pocket and axially coupling the guard element to the nipple section.

[0011] In one embodiment, a system for covering a sensitive component in a downhole string includes a joint section in the downhole string, the joint section including a longitudinal axis and a reduced diameter portion along the longitudinal axis. The system also includes a guard element positioned within the reduced diameter portion, the guard element including at least one pocket and at least one coupling extension radially extending from an inner surface of the guard element, the at least one coupling extension including a threaded hole at least partially parallel to the longitudinal axis. The system further includes a mounting section formed in the reduced diameter portion of the joint section, the mounting section including an aperture separated by a wall. The system includes a fastener positioned within the pocket, the fastener extending through the aperture and engaging the at least one coupling extension.

[0012] In one embodiment, a system for covering a sensitive component in a downhole string includes a joint section in the downhole string, the joint section including a longitudinal axis and a reduced diameter portion along the longitudinal axis. The system also includes a guard element positioned within the reduced diameter portion, the guard element including at least one pocket and at least one coupling extension radially extending from an inner surface of the guard element, the at least one coupling extension including a threaded hole at least partially parallel to the longitudinal axis. The system further includes a mounting section formed in the reduced diameter portion of the joint section, the mounting section including an aperture separated by a wall. The system includes a fastener positioned within the pocket, the fastener extending through the aperture and engaging the at least one coupling extension.

[0013] In one embodiment, a method for covering a sensitive component in a downhole string includes positioning the sensitive component within a reduced diameter portion of the downhole string. The method also includes covering at least a portion of the sensitive component via a guard element at least partially disposed within the reduced diameter portion, the guard element having at least one pocket and at least one coupling extension radially extending from an inner surface of the guard element into the reduced diameter portion. The method further includes positioning the at least one coupling extension adjacent to an aperture of a mounting section, the aperture receiving a locking element. The method also includes fastening the at least one coupling extension to the locking element via a fastener extending through a threaded hole of the locking element, the fastener disposed within the pocket. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present technology will be better understood by reading the following detailed description of non-limiting embodiments of the technology, taken in conjunction with the attached drawings, wherein:

[0015] Figure 1 is a cross-sectional side view of one embodiment of a drilling system according to an embodiment of the present disclosure;

[0016] Figure 2 is a perspective view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0017] Figure 3 is a perspective view of one embodiment of a tool joint having a reduced diameter portion according to an embodiment of the present disclosure;

[0018] Figure 4A is a partial exploded view of one embodiment of a locking element according to an embodiment of the present disclosure;

[0019] Figure 4B is a partial exploded view of one embodiment of a mounting system according to an embodiment of the present disclosure;

[0020] Figure 4C is a partial exploded view of one embodiment of a mounting system according to an embodiment of the present disclosure;

[0021] Figure 5A is a perspective view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0022] Figure 5B is a cross-sectional view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0023] Figures 6A-6G is a perspective view of one embodiment of a guard element according to an embodiment of the present disclosure;

[0024] Figure 7 is a perspective view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0025] Figure 8 is a perspective view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0026] Figure 9 is a perspective view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0027] Figure 10 is a perspective view of one embodiment of a guard element arranged on a tool section according to an embodiment of the present disclosure;

[0028] Figure 11This is a partial perspective view of one embodiment of a protective element arranged on a tool section according to an embodiment of this disclosure;

[0029] Figure 12 This is a cross-sectional view of one embodiment of a protective element arranged on a tool section according to an embodiment of the present disclosure;

[0030] Figure 13 This is a perspective view of one embodiment of the protective elements arranged on the tool section according to the embodiments of this disclosure;

[0031] Figure 14 This is a perspective view of one embodiment of the tool section according to the embodiments of this disclosure; and

[0032] Figure 15 This is a perspective view of one embodiment of a locking element for fixing a protective element according to the embodiments of this disclosure. Detailed Implementation

[0033] The foregoing aspects, features, and advantages of this disclosure will be further understood when considered in conjunction with the following description of embodiments and accompanying drawings. In describing the embodiments of this disclosure shown in the drawings, specific terminology will be used for clarity. However, this disclosure is not intended to be limited to the specific terminology used, and it should be understood that each specific term includes equivalents that operate in a similar manner to achieve similar purposes. Additionally, reference numerals may be reused for similar features between the drawings; however, such use is not intended to be restrictive and is for convenience and illustrative purposes only.

[0034] When describing elements of various embodiments of this disclosure, the articles “a,” “an,” “the,” and “the” are intended to mean the presence of one or more elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that additional elements may be included in addition to those listed. Any examples of operating parameters and / or environmental conditions do not exclude other parameters / conditions of the disclosed embodiments. Furthermore, it should be understood that references to “an embodiment,” “an embodiment,” “certain embodiments,” or “other embodiments” of this disclosure are not intended to be construed as excluding the existence of additional embodiments that also include the referenced features. Moreover, references to terms relating to orientation or direction, such as “above,” “below,” “upper,” “lower,” “side,” “front,” “rear,” or other terms, are made with reference to the illustrated embodiments and are not intended to limit or exclude other orientations or directions.

[0035] In some downhole operations, such as logging while drilling (LWD) operations, various tools, such as resistivity tools, can include antennas that are protected from the downhole environment by a guard (e.g., a guard plate, a cap, a mechanical shroud, a shroud, a guard element). For example, a segmented cover, such as a housing, spanning a portion of the circumference of a downhole tool string can be joined to a downhole junction (downhole tool) such as by welding or fasteners. Welded guards are not easily removable, while guards utilizing fasteners can be easily removable. Certain removable guards can include radial bolts to couple the housing to the junction or to couple the housings to each other. These guards have the problem of mechanical loading, as the force applied to the fastener is not in the preferred loading direction of the fastener (e.g., along the longitudinal axis of the fastener). Thus, shear stress can damage the bolts, leading to damage and / or removal of the guard, which can further lead to damage of the antenna. Various embodiments of the present invention overcome these shortcomings by providing a removable guard that is axially mounted to the junction. Thus, the fasteners are loaded along their preferred loading direction. Furthermore, the level of pretension is only oscillatory. There is no additional loading, such as bending or shear. Rotation of the downhole junction in a downhole tool string, such as a bottom hole assembly (BHA), is only translated into an oscillatory axial load (along the longitudinal axis of the fastener). Furthermore, the removability of the guard enables replacement of the antenna and also enables installation of different antenna configurations, thereby increasing the availability for a variety of tool configurations.

[0036] Embodiments provide pretension of the fasteners by implementing axial locking elements both uphole and downhole of the guard element. Thus, the guard element is pretensioned by the fasteners, where the pretension is also transmitted through the guard element. Contact is created between the locking elements and the sub-shoulder. In various embodiments, sufficient tension can be utilized to prevent wear or movement of the guard element. Furthermore, embodiments can include an insert or sacrificial component to absorb and / or dampen vibrations. In the present disclosure, the terms uphole, upstream, or upper refer to the direction oriented toward the surface of the Earth in a downhole tool string, while downhole, downstream, lower refer to the opposite direction oriented toward the bottom end of the downhole tool string (e.g., the drill bit end) or the bottom of the borehole in a downhole tool string, as opposed to the surface end of the downhole tool string or borehole.

[0037] In certain embodiments, a single axial locking element or a single fastener can be deployed, for example, against the upstream joint portion. Thus, the guard element can be tightened against the shoulder of the joint upstream of the guard element without a pre-tension being transmitted through the guard element. In embodiments, a flexible mount can be provided between the guard element and the joint portion downstream of the guard. Further, the flexible mount can be positioned radially between the guard and the joint, or a gap can be established to prevent radial contact between the guard element and the joint during bending of the tool string. In the present disclosure, radial refers to a direction 213( Figure 2 ) perpendicular to the longitudinal axis 212( Figure 2 ) of the tool string, tool, or joint.

[0038] It should be appreciated that a variety of different configurations of guard elements can be provided. For example, the guards can be half or multiple segments that are installed independently or connected to one another. The guard elements can be combined to define the longitudinal axis of the tool string completely or only partially. Further, the guard elements can include at least one slot or opening having a variety of different shapes. As will be described below, in certain embodiments, the shape of the slot or opening can be specifically selected based on the shape of a sensor or component associated with the slot or opening, such as an orientation of an antenna configuration, an antenna dipole moment, a sensor element such as a gamma sensor, a nuclear sensor, a pressure sensor, or an acoustic sensor. For example, the slot or opening can be shaped to accommodate the component such that the guard element protects the component from the downhole environment, such as from mechanical loads, but still provides an open section in which the component (e.g., an antenna, pressure sensor, etc.) can be in contact with the downhole environment, such as to allow electromagnetic fields, radiation, pressure, or acoustic waves to pass through the guard element. Additionally, the guards can include multiple segments that are additionally coupled together, for example, by welding. Embodiments can also include hinged components, threaded connections (e.g., tangentially oriented screws), or groove and tongue connections of the guard elements.

[0039] Various embodiments include at least one opening within the guard element to establish a connection between the sensor component and the downhole environment. The opening can also be filled with a different material than the material forming the guard element. The opening can be used to reduce the stiffness of the guard element, and the different material can include a material that is less stiff to provide improved flexibility. Further, in embodiments, the guards can include flexible sections, such as wave-shaped sections or reduced wall thickness sections.

[0040] Figure 1is a schematic side view of one embodiment of a wellbore system 100 including a rig 102 and a drill string 104 (e.g., a tool string) extending into a subterranean formation 106. It should be appreciated that while various embodiments can be discussed with reference to the depicted wellbore system 100, other embodiments can include other wellbore systems, which can include a wireline, coiled tubing, etc. Thus, the discussion with reference to the drill string 104 is for illustrative purposes only. The depicted drill string 104 is formed of a plurality of tubulars coupled together, e.g., via threads, and extends into the formation 106 to a bottom hole assembly (BHA) 108. In the depicted embodiment, the BHA 108 includes a plurality of measurement modules, which can also be referred to as joints or downhole tools, such as a core sampling unit 110, a resistivity measurement unit 112, and a nuclear measurement unit 114, a magnetic resonance measurement unit, and an acoustic measurement unit. In various embodiments, the BHA 108 can include additional or fewer units, and in addition, can be used to perform one or more downhole measurement operations. Further, it should be appreciated that the drill string 104 can include various other components that have been removed for simplicity and to clarify the discussion herein, such as a mud motor, a steering unit, drilling dynamics measurement units (inclination, azimuth, vibration, bending). Moreover, while embodiments can be discussed with reference to drilling operations, in other embodiments, measurements can be taken during drilling cycles, logging cycles, intervention cycles, etc.

[0041] As Figure 1 depicted in FIG. 1, in various embodiments, the wellbore 116 extends into the formation 106 and includes a borehole sidewall 118 and an annulus 120 disposed between the BHA 108 and the sidewall 118. In certain embodiments, during formation of the wellbore 116, the drill string 104 can include a drill bit that is driven in rotation. In various embodiments, a fluid, such as drilling mud, can be pumped through an inner bore of the drill string 104 and through the drill bit, where the drilling mud exits the BHA through nozzles and transports drill cuttings through the annulus to the surface. The drilling mud can infiltrate the formation 106 in a near-borehole region 122.

[0042] In various embodiments, the BHA 108 can be used to determine a location of a recoverable zone 124 within the formation 106. The recoverable zone 124 can refer to a region of the formation 106 that includes recoverable hydrocarbons. In addition, while the recoverable zone 124 is depicted as a region of the formation 106, in other embodiments, the recoverable zone 124 can include a region of the wellbore 116, such as a region of the borehole sidewall 118. Figure 1Not shown, but the wellbore 116 can also be curved or deviated (a slanted borehole), rather than just straight, thereby providing additional stresses and strains on the drill string 104 as it moves through the borehole and / or as it drills a deviated borehole. The various illustrated tools associated with the BHA 108 can include sensors disposed along the tools. The sensors can include antennas. The tools can include shields that provide protection to the sensors or a portion of the sensors from the wellbore environment. Embodiments of the present disclosure are directed to removable shields that are axially coupled to respective joints and / or to each other to provide improved resistance to stress when the drill string is rotated. High stresses are applied to the drill string, particularly when the drill string is rotated in a deviated borehole. Rotation in a deviated borehole can apply oscillating bending stresses to complex and sensitive downhole tool components in the BHA, such as a measurement unit.

[0043] A drilling tool has a section in which a sensor component, such as an LWD antenna, is located. The drilling tool and the drilling tool section include a tool body (joint body), respectively. To protect these sensor components, one or more shield elements are located in the area of the drilling tool (borehole joint) in which the sensor components are located. These shield elements protect the components from the downhole environment, such as contact with the borehole wall when tripping or drilling operations. In embodiments of the present disclosure, an axial mounting element couples the shield to the joint. In various embodiments, the axial mounting element includes a locking element and a fastener disposed within a pocket of the joint. The locking element extends through the pocket and is secured to the shield via the fastener. Thus, axial and radial movement of the shield element is prevented via contact between the joint shoulder and the locking element. Furthermore, the illustrated arrangement also prevents tangential movement (rotational movement about the longitudinal axis of the joint), which can be caused by torsional vibrations, such as high frequency torsional vibrations. In other words, a frictional contact can be provided that affects movement in a variety of different directions. It should be appreciated that in other embodiments, the pocket can be formed in the shield element, and the fastener can be introduced into an axial aperture formed in the joint body. The shield element can be formed of the same material as the joint or joint body, or can be formed of a different material than the joint or joint body. The joint body can be formed of steel, stainless steel, Inconel, titanium, or a metal alloy. The shield element can be formed of steel, stainless steel, Inconel, titanium, or a metal alloy, polyether ether ketone (PEEK), or a fiber-reinforced composite.

[0044] Figure 2is a perspective view of an embodiment of the tool segment 200 illustrating a guard element 202 (e.g., guard, guard plate, cover, mechanical shroud, shroud) coupled to a joint 204 via a mounting system 206 (e.g., mounting element). The guard element has a guard length along a longitudinal axis of the joint and a radial thickness in a radial direction perpendicular to the longitudinal axis of the joint. The illustrated guard 202 is disposed circumferentially around the joint 204. As will be described, in various embodiments, the guard 202 can be one part (e.g., slotted sleeve) or multiple parts (e.g., segmented parts) around a recess to build a circumferential guard (completely cover the perimeter). In other words, the circumferential arrangement can be provided by multiple segment components that combine to form a circumferential guard. Further, in various embodiments, the guard can be specifically selected to cover only a particular range of the perimeter of the joint (not completely cover the perimeter. In the illustrated embodiment, an outer guard diameter 208 is substantially equal to an outer joint diameter 210. However, as will be described below, it should be appreciated that the joint 204 can have a number of different diameters, for example, to include a reduced diameter portion in which one or more sensors or portions of sensors can be mounted. Further, in various embodiments, the guard element 202 can be larger or smaller than the joint diameter 210, for example, to provide additional space for components and / or to reduce or increase the outer diameter of the joint.

[0045] In the embodiment shown in Figure 2 the guard 202 is axially mounted to the joint 204 along a longitudinal tool axis or longitudinal joint axis 212. As used herein, "axially mounted" refers to utilizing a coupling element having an axis that is substantially parallel to the longitudinal tool axis 212. For example, in the illustrated embodiment, the mounting system 206 includes a locking element 214 and a fastener 216, which can be a bolt. A fastener longitudinal axis 218 is shown as being substantially parallel to the tool axis 212. Thus, the force used to couple the guard 202 to the joint 204 is disposed along the fastener longitudinal axis 218. This arrangement enables improved force loading on the fastener 216 and reduces shear forces across the body of the fastener 216 that can lead to fatigue and / or breakage.

[0046] The illustrated locking element 214 is disposed within a pocket 220 formed in the outer surface 201 of the joint 204. The pocket 220 is a recessed portion that can include a radial depth, a circumferential width, and an axial length that can be specifically selected based on design conditions. For example, the pocket length can be selected such that the fastener 216 and / or the locking element 214 can be positioned within the pocket 220 prior to installation. Further, the pocket 220 can include a depth such that the locking element 214 and / or the fastener 216 can be positioned within an outer diameter of the tool. The pocket 220 further includes a shoulder 222 that engages a mating shoulder 224 of the locking element 214. Thus, due to the contact between the shoulder 222 and the mating shoulder 224, axial movement of the locking element 214 in at least one direction is prevented. As noted above, it should be appreciated that reference to preventing axial movement should not be interpreted as only preventing axial movement of the locking element 214. For example, the provided frictional contact can also limit or prevent radial and / or tangential movement. The shoulder 222 and the mating shoulder 224 are annular shoulders having an extension in the radial direction. The shoulder 222 and the mating shoulder 224 are oriented substantially perpendicular to the longitudinal axis 212 of the joint. That is, the normal vectors of the shoulders 222 and 224 are substantially parallel to the longitudinal axis 212 of the joint segment.

[0047] As will be described below, in operation, the locking element 214 is disposed within the pocket 220 and the fastener 216 is coupled to the guard element 202 via an aperture that extends through both the locking element 214 and the guard element 202. Thus, for example, when a pair of mounting elements are used on both axial ends of the guard as described above and a pre-tension is provided to the fastener, axial movement can be locked relative to the tool longitudinal axis 212. In at least one embodiment, the fastener 216 is coupled to the locking element 214 such that a face of the fastener 216 is substantially flush with an end of the locking element 214. That is, the aperture that receives the fastener 216 can be larger or substantially the same diameter as the bolt head such that the fastener 216 can extend completely or nearly completely into the locking element 214. It should be appreciated that the size of the fastener 216 and / or the associated aperture can be selected specifically based at least in part on the intended design conditions.

[0048] In various embodiments, an interface 226 is formed between the guard element 202 and the joint 204. In certain embodiments, the guard element 202 is positioned to contact the joint 204 at both an upstream end 228 and a downstream end 230 of the guard. However, it should be appreciated that in various embodiments, one or more gaps 232 can be formed between the guard element 202 and the joint 204. That is, respective ends of the guard element 202 can not be pulled into contact with the joint 204 as will be described below.

[0049] Figure 3is a perspective view of a joint 204 illustrating a reduced diameter portion 300 (e.g., reduced diameter section) formed along a section 302 in an outer surface 201 of the joint 204. It should be appreciated that the joint 204 can be of any reasonable length, and additionally, the reduced diameter length 304 can also be of any reasonable length. Additionally, there can be multiple reduced diameter portions 300. Furthermore, the reduced diameter portions 300 can extend between one or more joints 204, however, in other embodiments, the reduced diameter portions 300 are described herein with reference to a single joint 204 for clarity. The reduction in diameter of the reduced diameter portion is dependent on the size of the sensor or sensor portion housed in the reduced diameter portion. In a drilling tool that includes an inner bore 205, the radial extension of the reduced diameter cannot be greater than the outer diameter of the joint minus the diameter of the inner bore. The minimum extension of the reduced diameter is the radial thickness of the guard, assuming the outer diameter of the guard is equal to the outer diameter of the joint.

[0050] In the illustrated embodiment, the reduced diameter portion 300 has a reduced diameter 306 that is less than the joint outer diameter 210. This reduced diameter portion 300 can form an area to receive one or more sensors (e.g., one or more antennas) associated with a downhole tool. The reduced diameter portion 300 can include a variety of different elements or protrusions to facilitate installation. For example, in Figure 3 a tapered section 308 is shown, however, this tapered section 308 is for illustrative purposes only and in various embodiments, there can be an abrupt change in diameter between adjacent sections of the reduced diameter portion 300. That is, a substantially planar or vertical edge can be positioned at the transition between the joint diameter 210 and the reduced diameter 306. Furthermore, it should be appreciated that the tapered section 308 can be a different shape, such as arcuate, linear, three center curve, or combinations thereof. The tapered section 308 can act as a stress reduction feature. It should be appreciated that additional structures can also be provided within the reduced diameter portion 300, such as mounting brackets, clamps, etc. Accordingly, the embodiment shown in Figure 3 is for illustrative purposes and has been simplified.

[0051] In Figure 3Also illustrated in the middle is a pocket 220 that includes an aperture 310 that extends through the pocket 220 and into the reduced diameter portion 300 (e.g., to an open area associated with the reduced diameter portion 300). In other words, the aperture 310 provides access to the reduced diameter portion 300 through the pocket 220. For example, in an embodiment, the locking element 214 can extend at least partially through the aperture 310 to facilitate connection between the guard element 202 and the joint 204. In this embodiment, the aperture 310 includes an aperture profile 312 that is shown as having a wall 314 that tapers inward (relative to the radial direction 213 in the tool). That is, a circumferential aperture opening 316 at an outer radial end of the aperture is larger than a circumferential aperture opening 318 at an inner radial end of the aperture. This arrangement is for illustrative purposes, and other embodiments can include a variety of different profiles to facilitate installation and coupling of the locking element 214 and / or the guard element 202. For example, the opening 318 can be larger than the opening 316. Further, the aperture 310 can be closed in the radial direction (closed radial portion) to inhibit radial movement of the locking element 214 after at least a portion extends through the aperture 310.

[0052] The reduced diameter portion 300 also includes annular stop shoulders 320a, 320b (upper and lower stop shoulders 320a, 320b) at each end of the longitudinal length 304 of the reduced diameter portion. The stop shoulders 320a / b are annular shoulders oriented substantially perpendicular to the longitudinal axis 212 of the joint. As noted above, in various embodiments, the stop shoulders 320 can be brought into contact with the axial ends of the guard element 202 (the upper end of the guard element 203a and the lower end of the guard element 203b). The axial ends 203a / b of the guard element include annular guard shoulders 207a / b (upper and lower guard shoulders 207a, 207b) on the axial ends 203a / b Figure 4A). The pre-tension applied to the fastener results in contact between the stop shoulder 320a / b and the guard shoulder 207a / b, which secures the guard element 202 to the joint 204. However, in an embodiment, a gap 232 can be formed between one or both of the stop shoulders 320 and the axial end 202a / b of the guard element 203. The gap can be formed circumferentially around the longitudinal axis 212 of the joint 204. The gap width is oriented parallel to the longitudinal axis 212 of the joint 204. Additionally, the first end of the guard element 202 can be in contact with the first stop shoulder of the reduced diameter portion 300, while the second end is not in contact with the second stop shoulder of the reduced diameter portion 300. Advantageously, in this embodiment, no threads or other receiving components are formed in the joint 204. For example, the stop shoulders 320a / b do not include threaded receptacles, but only apertures 310. This arrangement advantageously transfers the threaded or other fastening components to the guard element 202, which can be considered a removable and replaceable component (e.g., a lower cost component that is easier to replace than the joint 204). Thus, the guard element can be replaced or removed with reduced cost and time, while the axial securing of the guard element 202 to the joint and the axial orientation of the mounting system 206 avoids or significantly reduces bending and shear stresses on the mounting system 206 and included components. The reduced bending and shear stresses result in increased reliability of the mounting system, and thus the overall system. It should be appreciated that in various embodiments, the stop shoulders 320a / b or other portions of the joint 204 can include threaded elements or receiving components.

[0053] Figure 4Ais a partial exploded view of an embodiment of a locking element 214 engaging a guard element 202 via a fastener 216. The fastener 216 is illustrated in the depicted embodiment as a bolt extending through an aperture 400 formed in the locking element. The aperture can be a hole or a bore. The hole can be threaded or unthreaded. In at least one embodiment, the aperture 400 has a diameter that is larger than a diameter of the fastener 216. That is, the fastener 216 can be installed within the aperture 400 such that an end of the fastener 216 is substantially coplanar with an end of the locking element 214. In at least one embodiment, the aperture 400 can have a diameter that is larger than at least a first portion of the diameter of the fastener 216 but smaller than a diameter of at least a second portion of the fastener 216 such that a portion of the fastener 216 abuts a face of the locking element 214 when installed. The fastener 216 is aligned with a threaded hole 402 in the guard element 202. As noted above, the threading can be formed in replacement parts (e.g., the guard element 202, the locking element 214, etc.) without forming threads on the joint 204, which can improve longevity by shifting the components subject to wear to less expensive, easily replaceable components. In operation, the locking element 214 is disposed within the pocket 220 and the fastener 216 extends through the aperture 400 to engage the threaded hole 402, thereby securing the locking element 214 to the joint 204 and the guard element 202. The fastener includes a shoulder 217 that engages a shoulder 405 in the locking element on an upstream end of the locking element. The locking element 214 includes a shoulder 407 at a downstream end. The shoulder 407 at the downstream end of the locking element engages the guard shoulder 207a at the upstream end of the guard. In alternative embodiments, the shoulder 217 in the fastener directly engages an upstream shoulder in the pocket. For a mounting system 206 oriented on a downstream side of the guard element, the orientation of the shoulder is reversed from the orientation of the shoulder in the mounting system upstream of the guard element, upstream becomes downstream, and downstream becomes upstream. It will be appreciated that reference to threaded holes is for purposes of illustration and other embodiments can include different configurations, such as an interference fit, a locking member, a spring-loaded pin, etc. Thus, the threaded hole 402 is shown as an example of a mechanism for effecting coupling of components. In certain configurations, a longitudinal axis 218 of the fastener is parallel to a longitudinal axis 212 of the joint. However, an angle between the longitudinal axis of the fastener and the longitudinal axis 212 of the joint is possible. In the case where the longitudinal axis of the fastener is inclined relative to the longitudinal axis of the joint, the force transfer path F( Figure 5A) should be correspondingly inclined. The longitudinal axis of the fastener can form an angle of about 1 to 3 degrees, about 1 to 5 degrees, about 1 to 10 degrees, about 1 to 15 degrees, about 1 to 20 degrees, about 1 to 30 degrees, or about 1 to 45 degrees with the longitudinal axis of the joint. At least a portion of the shoulder in the force transmission path can be correspondingly inclined. That is, the normal vector of the inclined shoulder is parallel to the inclined longitudinal axis of the fastener and forms the same angle with the longitudinal axis of the fastener and the longitudinal axis of the joint. The same applies to the aperture in the locking element 400 and the threaded hole 402 in the guard. In the case of an inclined fastener with respect to the longitudinal axis of the joint, the locking element can also be inclined. There is no fastener 216 in the installation system 206 that is oriented substantially in the radial direction, and there is no shoulder in the installation system that has a normal vector oriented substantially in the radial direction.

[0054] The locking element 214 comprises an elongated body portion 404 oriented substantially along the longitudinal axis 212 of the joint and coupled to a head portion 406 oriented substantially perpendicular to the longitudinal axis 212 of the joint and substantially perpendicular to the radial direction of the joint and having a greater width in the circumferential direction than the elongated portion 404, forming a mating shoulder 224 of the shoulder 222 of the joint pocket 220. In various embodiments, the locking element 214 further comprises a mating profile with respect to the aperture profile 312. For example, the mating profile of the locking element 214 can coincide with the aperture profile 312 to facilitate engagement. Additionally, it will be appreciated that the aperture profile 312 and the mating profile of the locking element 214 can be specifically selected to provide additional benefits, such as blocking radial movement of the guard element 202.

[0055] To install the guard element 202 on the joint 204, a pretension can be established by implementing the locking element 214 located above and below the well of the guard element 202. Thus, the guard element 202 is pretensioned by the fastener 216, and the pretension is transmitted through the guard element 202. In certain embodiments, contact is created at the stop shoulder 320a / b. To avoid fretting wear on the stop shoulder 320a / b and / or the guard shoulder 207a / b of the guard element 202 during bending of the drill string, a pretension is applied having a value of the contact state of the locking shoulder 320 during bending.

[0056] Figure 4Bis a partial exploded view of an embodiment of the locking element 214 engaging the joint 204 at the pocket 220. In this embodiment, the aperture 310 has a triangular shape in cross-section perpendicular to the longitudinal axis of the joint 212, including a wall 314 that tapers outward (relative to the radial direction 213 in the tool). That is, a circumferential opening 316 at an outer radial end of the aperture is smaller than a circumferential opening 318 at an inner radial end of the aperture. Thus, radial movement of the locking element 214 and the fastener 216, and thus the guard element 202, is prevented. For example, the illustrated locking element 214 includes a mating profile 408 along at least a portion of the body 404 of the locking element. Thus, the locking element 214 can extend through the aperture 310 and conform to the aperture profile 312. That is, the elongated body portion 404 of the locking element is also tapered, with the taper conforming to the taper in the aperture. As will be appreciated, in various embodiments, the locking element 214 can be installed such that the head 406 is pulled into contact with the pocket 220, bringing the shoulder 222 into contact with the mating shoulder 224. It will be appreciated that in various embodiments, the respective profiles 312, 408 can differ from those illustrated in Figure 4B . Additionally, in various embodiments, the profiles 312, 408 can include features that provide an interference between movement in various directions. Further, it will be appreciated that the opening 316 can be closed, thus forming an opening or aperture that is bounded on all sides that extends through the joint. The tapered wall in the aperture can extend along the entire longitudinal length of the aperture or only along a portion of the longitudinal length of the aperture. The tapered wall avoids loss of the locking element 214 into the wellbore in the event of a lost fastener 216.

[0057] Figure 4C is a partial detailed view of an embodiment of the locking element 214 engaging the joint 204 at the pocket 220. As noted above, the aperture profile 312 illustrated in Figure 4C differs from the profile of Figure 4B in that the respective profiles 312, 408 are substantially rectangular. In this embodiment, the guard element 202 includes an axial extension 410 at one of the axial ends within the aperture 310. Within the aperture 310, the axial extension engages the body 404, facilitating coupling of the guard element 202 to the locking element 214, e.g., via the fastener 216. The engagement of the body 404 of the locking element 214 and the axial extension 410 of the guard element 202 can be within the aperture 310. As will be appreciated, with the embodiment of the configuration shown in Figure 4C , further resistance to circumferential movement of the guard element 202, as well as resistance to axial movement, can be received due to the arrangement within the aperture 310.

[0058] Figure 5Ais a perspective view of an embodiment of the tool section 200, in which the guard element 202 is secured to the junction 204 with a single mounting system 206. In this example, the mounting system 206 is arranged on the uphole side (e.g., closer to the surface). As described in detail above, the mounting system 206 includes a locking element 214 positioned within a pocket 220. A fastener 216 engages a threaded hole 402 of the guard element 202 to secure the locking element to the guard element 202. The mating shoulder 224 can be brought into engagement with the shoulder 222, thereby preventing radial and axial movement of the guard element 202 in at least one direction. Furthermore, in embodiments, the end of the guard element 202, and the guard shoulder 207a with it, is brought into contact with the stop shoulder 320 on the upstream side of the reduced diameter portion 300. In contrast to the previous configurations, however, Figure 5A Embodiments of the present application do not include a pre-tension through the guard element 202, which can create an axial gap 232 and / or can include a gap material. Other embodiments can also include a radial gap between the guard element 202 and the reduced diameter portion 300 to facilitate bending. The axial gap can be filled with a material having specific properties, such as mechanical, electrical, magnetic, nuclear, and acoustic properties. The gap can avoid direct contact between the guard element and the junction section in the case of bending, thereby reducing mechanical stress. The gap can be filled with a material having specific electrical properties to improve the measurement quality of resistivity sensors. The gap can be filled with a material having specific acoustic properties to improve the measurement quality of acoustic sensors. The material in the gap can be polyether ether ketone (PEEK), rubber, elastomer, or epoxy.

[0059] Figure 5B is a cross-sectional side view of the tool section 200, in which a flexible mount 500 is arranged radially between the guard element 202 and the junction 204. As described above, this portion of the junction 204 is at the reduced diameter portion 300. The illustrated flexible mount 500 can include a spring, rubber, elastomer, or other elastic element that enables, reduces, or suppresses radial movement of the guard element 202 relative to the junction 204. Thus, bending of the downhole tool can be achieved without driving the guard element 202 into the junction 204, which can potentially damage the components or reduce the working life of the components. It should be appreciated, however, that in other embodiments, the flexible mount 500 can be replaced by a radial gap between the guard element 202 and the junction 504. The radial gap can be filled with air.

[0060] Figures 6A-6Gis a perspective view of an embodiment of a guard element 202 that includes various features that can be incorporated individually or in combination. Thus, it should be appreciated that while embodiments can include a single feature, various embodiments can combine two or more features. Each of the guard elements 202 can be incorporated with the axial installation methods described herein. Various embodiments can include features such as segmented guards, split guards, guard segment coupling systems, slotted sleeves, guard openings, guard flexible segments, etc.

[0061] Figure 6A includes a guard element 202 in a segmented configuration 600. A split forms a first housing segment 602 (e.g., a first guard segment) and a second housing segment 604 (e.g., a second guard segment), each of the housing segments 602, 604 spanning approximately 180 degrees. It should be appreciated that this arrangement is one example of a split housing configuration, and in other embodiments, the guard element 202 can be split into 3 parts, 4 parts, 5 parts, 6 parts, or any reasonable number of parts. Further, it should be appreciated that each part can have a different size. For example, as one example, a configuration with 3 parts can include one segment of approximately 180 degrees, such as the first housing segment 602, while the other segments are 90 degrees. In this embodiment, each segment 602, 604 includes a pair of circumferential ends 606, where the segments 602, 604 can be put together to form a full guard arrangement around a tool. In certain embodiments, as will be described below, additional components can be utilized to fasten the segments together. Also as Figure 6A As illustrated in the middle, one or more threaded holes 402 are positioned in and around each axial end 608, 610 (e.g., end face, guard shoulder 207a / b) of the respective segments 602, 604. In certain embodiments, each of the one or more threaded holes 402 is used to secure the respective segment 602, 604. In embodiments with more than one threaded hole, a variety of different installation positions are possible (e.g., the guard can not be aligned in a particular position).

[0062] Figure 6B is a perspective view of a guard element 202 in a split configuration 612, where the guard element 202 includes an opening having a circumferential width or discontinuity 614 that extends along the axial length of the guard 302. The illustrated split configuration 612 can provide flexibility during operation. In some embodiments, the guard element 202 can be partially deformed, for example by expanding the guard element 202 at the opening 614, to be installed on a tool string.

[0063] Figure 6Cis a perspective view of the guard element 202 in an assembled configuration 616. As shown, the segments 602, 604 are joined together around the perimeter of the tool. The segments 602, 604 can be joined together via a variety of joining processes, such as welding, adhesives, or other joining processes. In various embodiments, the segments 602, 604 can be joined together via a joining process that is performed after the segments 602, 604 are positioned on the tool. For example, the segments 602, 604 can be positioned on the tool via a variety of processes, such as via a welding process or a tongue and groove connection. The segments 602, 604 can then be joined together after the segments 602, 604 are positioned on the tool via a joining process, such as via a welding process or a tongue and groove connection.

[0064] Figure 6D is a perspective view of the guard element 202 in a hinged configuration 620. As shown, a hinge system 622 is positioned at a first circumferential end 624 opposite the opening 614. Thus, the illustrated segments 602, 604 can pivot about the hinge system 622, thereby enabling installation about the tool. As noted above, in various embodiments, there can be multiple hinge systems for coupling multiple segments together.

[0065] Figure 6E is a perspective view of the guard element 202 in a coupled configuration 626, which includes a channel 628 to facilitate coupling with components protected by the guard element. The illustrated channel 628 includes a variety of axial channel lengths 630 and channel circumferential widths 632 that can be selected based on a variety of different factors. The channel 628 can be aligned with the configuration of various sensing components in the sensor, such as an antenna, to facilitate coupling of the component to the tool. It should be appreciated that in various embodiments, the channel 628 can also be filled or otherwise surrounded by additional material that can have a reduced hardness or stiffness compared to the guard element 202. For example, one or more inserts can be utilized to provide further protection after the connection has been formed. The material in the channel can have specific electrical, magnetic, acoustic, optical, or mechanical properties. The material can be optimized, for example, to allow the passage of electromagnetic fields, magnetic fields, acoustic waves, optical waves, nuclear radiation (neutrons, gamma), or can be prepared to withstand pressure or mechanical impact. The material in the channel can be an electrically conductive or non-conductive material. It can have a certain magnetic permittivity or a certain permittivity. The material in the channel can be polyether ether ketone (PEEK), rubber, elastomer, or epoxy. The material in the channel can allow the passage of fluids, such as a mesh material, a lattice, or a skeleton structure.

[0066] Figure 6F is a perspective view of the guard element 202, illustrating a variety of different configurations of the guard element 202. As shown, the guard element 202 can include a variety of different configurations, such as a hinged configuration 620, a coupled configuration 626, or an assembled configuration 616. In various embodiments, the guard element 202 can include a variety of different configurations, such as a hinged configuration 620, a coupled configuration 626, an assembled configuration 616, or a combination thereof. Figure 6EThe channels 628 are oriented substantially along the circumference of the tool. In various embodiments, the channels 628 can also facilitate attachment to components, as well as reduce the stiffness of the guard element 202. For example, the channels 628 can reduce the axial stiffness of the guard element 202 or can reduce the bending stiffness of the guard element 202. As described above, the channels 628 can include a variety of different axial lengths 630 and circumferential widths 632, and additionally, can be filled with additional material. The axial length can extend about the circumference of the joint by about a particular angle. The angle can be between about 10 degrees to about 180 degrees, about 10 degrees to about 90 degrees, about 10 degrees to about 50 degrees, or about 10 degrees to about 30 degrees.

[0067] Figure 6G is a perspective view of the guard element 202, illustrating the flexible section 634 between the respective end sections 636, 638. For example, the flexible section 634 can be a bellows-type section having ridges or folds to facilitate expansion and contraction in response to external forces. In other embodiments, the flexible section 634 can be made of a different material than the end sections 636, 638 to achieve additional flexing, for example, by using a less stiff material such as rubber, elastomer, or titanium. Thus, bending of the tool can be accommodated while maintaining the presence of the guard element 202.

[0068] Figure 7 is a perspective view of one embodiment of the tool section 200 including a joint 204 having one or more recesses or hatches 700 positioned to receive guard sections 702. In the illustrated embodiment, the diameter-reducing portion 300 does not extend circumferentially around the tool section 200 as in the configuration shown in Figure 3 , but rather one or more ribs 704 of the joint 204 extend along the length of the joint 204. The recesses have a circumferential width and an axial length. The one or more recesses 700 are positioned at different regions around the tool axis 212 and include separate guard elements 202, shown here as sections 702, arranged within the respective recesses 700. As described above, the sections 702 are coupled to the joint 204 via the mounting elements 206. Thus, it should be appreciated that the one and more sections 702 share the features described previously herein, such as the threaded holes 402, etc.

[0069] Figure 8is a perspective view of one embodiment of a tool section 200 that includes a guard element 202 having a plurality of cover features 800 disposed at an end 610 opposite an end 608 that engages a mounting system 206. The cover features 800 are arranged as fingers separated by a space or aperture 802. The space is oriented in a longitudinal direction. However, it should be appreciated that embodiments of the present disclosure can utilize other layouts. The space 802 can extend radially through the guard element into the reduced diameter portion 300 where sensor components are disposed. As depicted, mounting elements 206 are used to secure the guard element 202 in place.

[0070] In the depicted embodiment, the cover features 800 at the end 610 are positioned in alignment with mating features 804 formed in the joint 204. That is, there are no second set of mounting elements 206 at the end 610. However, it should be appreciated that in other embodiments, mounting elements 206 can be at the end 610 and cover features 800 can be at the end 608. Thus, in various embodiments, the cover features 800 are used to cover only an axial portion of the area that houses the sensor components in the reduced diameter portion 300. The mating features 804 allow for placement of portions of the sensor, such as ferrite elements. Ferrite elements can be best placed axially outside of the actual sensor (e.g., antenna). Placement of ferrite in the mating features can improve the properties of the sensor.

[0071] Figure 9 is a perspective view of one embodiment of a tool section 200 with the mounting system moved to the guard element 202. Thus, various features described herein can be transferred to the joint 204, such as threaded holes 402. The guard element has an outer surface 221a and an inner surface 221b. In addition, the depicted pockets 220 can be formed in the outer surface 221 of the guard element 202. It should be appreciated that the pockets in the guard can be holes that extend completely through the guard element in a radial direction. Such an alternative arrangement still provides axial loading of the fasteners 216. In addition, it should be appreciated that while the depicted embodiment includes fasteners 216 having heads that are larger than the apertures, in other embodiments, the heads can be smaller than or substantially the same size as the apertures, and thus, the fasteners 216 can be flush with the end surface within the pocket or can extend into the aperture. The pockets 220 in the mounting system can be holes or drilled holes that extend through the guard element 202.

[0072] Figure 10is a perspective view of one embodiment of a tool segment 200 that includes a guard element 202 arranged such that mounting elements 206 are used to couple different segments 1002, 1004 of the guard element 202 together. In the depicted embodiment, the first housing segment 1002 includes a mounting system 206, such as a pocket 220 that receives a locking element 214 to engage the second segment 1004. Thus, the second segment 1004 can include threaded holes 402, as well as other elements to secure fasteners 216 to secure the first segment 1002 to the second segment 1004. Additionally, other features are depicted in the first and second segments 1002, 1004, such as channels 628. As shown, these features are aligned, which can indicate alignment of various elements corresponding to the mounting system 206, such as the location of threaded holes 402 in the guard element 202 Figure 6A

[0073] Figure 10 Also depicted is the mounting system 206 that is also positioned on the second segment 1004 to engage the first segment 1002. It should be appreciated that each of the segments 1002, 1004 can span different circumferential distances (angles) in various embodiments. For example, they can be half segments (e.g., 180 degrees) or quarter segments (e.g., 90 degrees), or any other range or combination thereof. The segments 1002, 1004 can also have different axial lengths. For example, the segment 602 can be shorter in axial extension than the segment 604. The depicted arrangement can also include a gap 232 Figure 5A between the guard element 202 and the joint 204, providing space for bending or movement of the guard element 202.

[0074] Figure 11 is a perspective view of one embodiment of a tool segment 200, where portions of the segments 1002, 1004 have been removed to depict a mounting segment 1100 arranged within the diameter-reduced portion 300. The depicted mounting segment 1100 includes a plurality of slots 1102 separated by walls 1104. The walls 1104 extend in a radial direction from an outer surface of the joint segment in the diameter-reduced portion 300. All of the walls together form a circumferential wall ring around the perimeter of the joint segment having the diameter-reduced portion. Each wall can extend more in a circumferential direction than in an axial direction. The slots are also referred to as apertures. The slots 1102 each form a slot profile (aperture profile) with the walls 1104. The mounting segment 1100 can be specifically selected to receive both sensor components (not depicted) and fasteners 216. For example, in certain embodiments, the mounting segment 1100 can be used in place of the locking elements 214.

[0075] ​In various embodiments, the slots 1102 are arranged to correspond to the passages 628 within the segments 1002, 1004, thereby providing access to the sensors, e.g., coupling, etc. However, it should be appreciated that in other embodiments, the slots 1102 can be misaligned to provide enhanced protection of the sensor components.

[0076] The segments 1002, 1004 are further illustrated in Figure 11 corresponding lip 1106 that extends radially inward and can abut the stop shoulder 320. However, as noted above, a gap can also exist between the lip 1106 and the stop shoulder 320. The lip 1106 can engage the reduced diameter portion 300 to align the apertures of the passages 1002, 1004 with the slots 1102 to facilitate coupling via the fasteners 216. The lip also provides mechanical coupling of the sensor components in the reduced diameter portion 300 with the guard element 202. The lip ensures that relative movement between the sensor components and the guard element 202 is not possible.

[0077] Figure 12 is a cross-sectional view perpendicular to the longitudinal axis 212 of one embodiment of the tool segment 200, illustrating a sensor component 1200 arranged within a slot 1102 formed in the mounting segment 1100. In this embodiment, the slot 1102 housing the sensor component 1200 is aligned with the passage 628. Further, in the illustrated embodiment, the fastener 216 extends through both the slot 1102 and a coupling extension 603 in the segment 1002. Thus, radial movement of the segment 1002 can be prevented, while in certain embodiments, axial movement and / or bending of the tool segment is facilitated. The coupling extension can include a threaded hole. Upon mounting, the fastener engages a first coupling extension (not shown) in the segment 1004. The first coupling extension includes a non-threaded aperture for the fastener to pass through. The fastener then passes through the slot in the mounting segment and engages the second coupling extension 603, which includes a threaded hole to secure the fastener. In embodiments, both coupling extensions engaged by the fastener can include threaded holes.

[0078] Figure 13 is a perspective view of one embodiment of a guard element 202 arranged along the tool segment 200. As noted above, the guard element 202 can be used to protect and / or secure one or more sensors associated with the tool segment. The illustrated guard element 202 can be referred to as a segmented guard element 1300, such as FIGS. 6 and Figure 9The guard element depicted in FIG. 13 is similar to the guard element 202 depicted in FIG. 6, in that the guard element 1300 includes a plurality of segments 1302, 1304 (very similar to segments 602, 604). In the depicted embodiment, the first segment 1302 and the second segment 1304 are disposed proximate to one another at an interface 1308, which in this embodiment extends through the passage 628. As indicated above, the passage 628 disposed along the guard element 1300 can provide access to the sensor while still maintaining a protective layer around the sensor. Additionally, as also described, the respective width, length, and number of passages 628 can be specifically selected based on operating conditions, and thus, the embodiment including three passages 628 of equal size is for illustrative purposes only.

[0079] The segments 1302, 1304 of the guard element 1300 are secured to the tool body via one or more fasteners 216 that engage one or more elements of the mounting element as described above. In this embodiment, the fasteners are disposed within illustrated voids or openings 1310 (pockets) in the guard element 1302, 1304 to facilitate external access. As will be described herein, the fasteners 216 can engage one or more elements of the mounting element 206, such as the locking elements 214 that interact with the mounting segment 1100a, to secure the segments 1302, 1304 in place. As previously indicated, the fasteners 216 can be coupled to an aperture that is smaller than, larger than, or substantially equal in diameter to one or more portions of the fasteners 216, such that the fasteners 216 can be flush with the ends of the locking elements 214 and / or can extend completely into the locking elements 214. In the depicted embodiment, the geometry of the voids 1310 is different than the passages 628, however, it should be appreciated that in other embodiments they can be the same. Further, the size of the voids 1310 is shown for illustrative purposes and can vary based on a variety of factors, such as fastener length, etc.

[0080] In various embodiments, as described above, the respective segments 1302, 1304 can include a radially extending portion 1306 (e.g., a coupling extension) for securing the segments 1302, 1304 to the tool body, similar to the Figure 12 configuration depicted in FIG. 11. For example, the coupling extension 1306 can extend radially inward from an inner surface of the guard element toward the tool body and include an aperture for receiving a portion of the fasteners 216 and / or the mounting element 206. In certain embodiments, the coupling extension 1306 can be disposed axially uphole of a component of the mounting segment 1100, such as the walls 1104a and 1104b, or axially downhole of the component of the mounting segment to provide a stop feature that resists axial movement of the guard element. The coupling extension includes an aperture or hole for the fastener to pass through. The hole in the coupling extension can not include threads.

[0081] Figure 14 is a perspective view of one embodiment of a tool section 200 that includes a mounting section 1100 that includes walls 1104a and 1104b and slots 1102a and 1102b. In this configuration, each slot 1102a or 1102b is surrounded by a pair of walls 1104a or 1104b, thereby forming at least a portion of a shoulder 222a or 222b for engagement with one or more mounting elements 206, as described above. The shoulders 222a and 222b include a normal vector that is substantially parallel to the longitudinal axis 212 of the joint section. The mounting section 1100 can include one or more circumferential rings of walls. The one or more circumferential rings of walls share an axis of symmetry, which can be the longitudinal axis 212 of the joint section. The one or more circumferential rings of walls can include different numbers of walls (e.g., the number of walls 1104a can not equal the number of walls 1104b). In one non-limiting example, all of the walls in one circumferential ring can extend the same distance in a radial direction from the diameter-reducing portion 300 and can all have the same axial extension. The walls in different circumferential rings can extend the same distance in a radial direction from the diameter-reducing portion 300 and can have the same axial extension. The walls 1104a and 1104b include side walls 1223 and 1224 that surround the slots 1102a and 11202b. Each wall includes two side walls 1223a, 1223b and 1224a, 1224b. As described above, in various embodiments, the slots 1102a, 1102b can be arranged circumferentially around the tool body (the slots have a circumferential width) and can be arranged in a particularly selected configuration based on design conditions. For example, the space between the slots 1102a, 1102b can form a mounting area for various sensors, etc. In addition, the slots 1102a, 1102b can also receive one or more sensors.

[0082] Figure 15 is a perspective view of one embodiment of a portion of a mounting element. The locking element 214 engages the slot 1102 of the mounting section 1100. As described above, for example, at least with respect to the embodiment of FIG. 10, the locking element 214 can be a pin that is received in the slot 1102. The pin 214 can be received in the slot 1102 in a manner that allows the pin 214 to move in a radial direction relative to the longitudinal axis 212 of the joint section 200. The pin 214 can be received in the slot 1102 in a manner that allows the pin 214 to move in an axial direction relative to the longitudinal axis 212 of the joint section 200. The pin 214 can be received in the slot 1102 in a manner that allows the pin 214 to move in a circumferential direction relative to the longitudinal axis 212 of the joint section 200. The pin 214 can be received in the slot 1102 in a manner that allows the pin 214 to move in a radial direction, an axial direction, and a circumferential direction relative to the longitudinal axis 212 of the joint section 200. Figure 2The illustrated locking element 214 extends through the slot 1102 (e.g., the aperture 310) such that the shoulder 222 of the wall 1104 engages the mating shoulder 224 of the locking element 214. Thus, the aperture 400 formed in the locking element 214 can receive the fastener 216. As noted, the aperture 400 can have a diameter that is greater than, less than, or substantially equal to one or more portions of the fastener 216 such that the fastener 216 can have an end that is substantially flush with the mounting element 206, abutting the locking element 214, and / or fully extending into the locking element 214. In various embodiments, a coupling extension 1306 (not shown) is disposed between the fastener (not shown) and a side 1500 of the wall 1104 that is opposite the side of the wall 1104 that provides the shoulder 222. The coupling extension can also include an aperture for receiving the fastener 216, thereby securing the segments 1302, 1304 to the mounting segment 1100 and preventing axial and radial movement of the segments 1302, 1304. Upon installation, the mounting system, fastener passes through the opening 1310, through the aperture in the coupling extension 1306, through the slot in the mounting segment, and engages the locking element 214, which includes a threaded hole (not shown), to secure the fastener. The fastener 216 can pass through the slot 1102 within the locking element 214. The side of the wall that includes the shoulder 222 can be referred to as the upstream side or the downstream side of the wall 1104, depending on which side the fastener enters the slot from. If the fastener 216 enters the slot 1102 from the downstream side, Figure 13 ), the shoulder 222 is on the upstream side of the wall 1104. In this configuration, the downstream side of the wall opposite the upstream side of the wall includes the side 1500 of the wall 1104 that abuts the coupling extension 1306. If the fastener enters the slot from the upstream side, the shoulder 222 is on the downstream side of the wall, and the side 1500 is on the upstream side of the wall 1104.

[0083] The guard element 1302, 1304 (e.g., the first segment and the second segment) can include more than one mounting system, including more than one coupling extension 1306. In a configuration with two mounting systems, a first mounting system can be configured as described above, including a first wall 1104a, a first slot 1102a, a first locking element 214a, a first coupling extension 1306a, and a first fastener 216a that enters the first slot 1102a from the downstream side through the first coupling element 1306a. The first locking element 214a includes a first mating shoulder 224a that engages a first shoulder 222a on the upstream side of the first wall 1104a Figure 13 and Figure 15). A second mounting system (not shown) can be located at a different location on the perimeter of the guard element (e.g., about 10 to 45 degrees from the first mounting system). The second mounting system can be configured such that a second fastener 216b extends from an upstream side through a second coupling extension 1306b into a second slot 1102b between second walls 1104b. A second mating shoulder 224b on the second locking element 214b engages a second shoulder 222b on a downstream side of the walls 1104b.

[0084] In Figure 15 the configuration shown in Figure 4B is similar to that of the configuration of For example, the opening 318 of the slot 1102 is larger than the opening 316, which prevents radial outward movement. The opening 316 is radially outward from the opening 318. The radius from the tool center to the opening 318 is less than the radius from the radial tool center to the opening 316. Thus, when coupled to the segments 1302, 1304, the locking element 214 can prevent outward radial movement of the guard element 1300.

[0085] Embodiments can also be described in view of the following clauses:

[0086] 1. A system for covering a sensitive component in a downhole string, the system comprising:

[0087] a junction segment in the downhole string, the junction segment comprising a longitudinal axis and a reduced diameter portion along the longitudinal axis;

[0088] a guard element disposed on the reduced diameter portion; and

[0089] a mounting system adapted to axially couple the guard element to the junction segment, the mounting system comprising:

[0090] a pocket in one of the junction segment and the guard element, the pocket comprising a shoulder; and

[0091] a threaded bore in the other of the junction segment and the guard element, the threaded bore oriented at least partially parallel to the longitudinal axis of the junction segment; and

[0092] a fastener that engages the threaded bore through the pocket and axially couples the guard element to the junction segment.

[0093] 2. The system of clause 1, further comprising:

[0094] a locking element comprising an elongated body portion oriented at least partially along the longitudinal axis of the joint segment; and a head portion oriented at least partially perpendicular to the longitudinal axis of the joint segment.

[0095] 3. The system of clause 1, wherein a fastener axis and the threaded bore are arranged parallel to the longitudinal axis of the joint segment.

[0096] 4. The system of clause 1, wherein the pocket is in an outer surface of the joint segment, and the installation system further comprises:

[0097] an aperture formed through the pocket, the aperture coupling the reduced diameter portion to the pocket, the aperture comprising a profile; and

[0098] a locking element extending through the aperture, the locking element comprising a mating profile, wherein the mating profile corresponds to the profile of the aperture.

[0099] 5. The system of clause 4, wherein the profile of the aperture comprises a tapered wall arranged to resist movement of the locking element in a radial direction.

[0100] 6. A system for covering sensitive components in a downhole string, the system comprising:

[0101] a joint segment in the downhole string, the joint segment comprising a longitudinal axis and a reduced diameter portion along the longitudinal axis;

[0102] a first guard element within the reduced diameter portion, the first guard element comprising a first coupling extension extending radially from an inner surface of the first guard element, the first coupling extension comprising a threaded hole at least partially parallel to the longitudinal axis;

[0103] a second guard element comprising a second coupling extension extending radially from an inner surface of the second guard element, the second coupling extension comprising a hole;

[0104] an installation segment formed in the reduced diameter portion of the joint segment, the installation segment comprising an aperture separated by a wall; and

[0105] a fastener positioned within the pocket, the fastener extending through the hole of the second coupling extension and the aperture and engaging the first coupling extension.

[0106] 7. The system of clause 6, wherein a fastener axis is arranged parallel to the longitudinal axis of the junction segment.

[0107] 8. The system of clause 1, wherein the guard element further comprises:

[0108] a flexible segment.

[0109] 9. A system for covering sensitive components in a downhole string, the system comprising:

[0110] a junction segment, the junction segment being in the downhole string, the junction segment comprising a longitudinal axis and a reduced diameter portion along the longitudinal axis;

[0111] a guard element positioned within the reduced diameter portion, the guard element comprising at least one pocket and at least one coupling extension, the at least one coupling extension extending radially from an inner surface of the guard element, the at least one coupling extension comprising a bore;

[0112] a mounting segment formed in the reduced diameter portion of the junction segment, the mounting segment comprising an aperture separated by a wall;

[0113] a locking element extending axially through the aperture, the locking element comprising a threaded bore at least partially parallel to the longitudinal axis; and

[0114] a fastener positioned within the pocket, the fastener extending through the bore in the at least one coupling extension, through the aperture, and into the threaded bore of the locking element.

[0115] 10. The system of clause 9, wherein the locking element further comprises:

[0116] an elongated body portion oriented at least partially along the longitudinal axis of the junction segment; and

[0117] a head portion at least partially perpendicular to the longitudinal axis of the junction segment.

[0118] 11. The system of clause 9, wherein a fastener axis is arranged parallel to the longitudinal axis of the junction segment.

[0119] 12. The system of clause 9, wherein the aperture comprises a profile, and the locking element comprises a mating profile, wherein the mating profile corresponds to the profile of the aperture.

[0120] 13. The system of clause 12, wherein the profile of the aperture is defined by at least one side of the wall, the at least one side of the wall being tapered, wherein the profile of the aperture is arranged to impede movement of the locking element in a radial direction.

[0121] 14. The system of clause 9, wherein the joint section includes a perimeter, and the guard element covers at least a portion of the perimeter of the joint section.

[0122] 15. The system of clause 9, wherein the guard element includes at least a first guard element and a second guard element, each of the first and second guard elements being axially coupled to the joint section by at least one fastener and at least one locking element.

[0123] 16. The system of clause 9, wherein the guard element is axially coupled to the joint section using a second fastener and a second locking element, the fastener and the second fastener and the locking element and the second locking element being at different circumferential locations in the guard element.

[0124] 17. The system of clause 9, further comprising an annular shoulder on the wall, wherein a normal vector of the annular shoulder is oriented parallel to the longitudinal axis of the joint section.

[0125] 18. The system of clause 9, wherein the guard element is made of a first material and includes at least one channel, wherein the channel is filled with a second material different from the first material.

[0126] 19. The system of clause 9, further comprising:

[0127] a flexible mount radially positioned between the guard element and the reduced diameter portion.

[0128] 20. The system of clause 9, further comprising:

[0129] at least a portion of a sensor in the reduced diameter portion, wherein the at least a portion of the sensor is covered by the guard element.

[0130] 21. The system of clause 9, wherein the guard element further comprises a lip that extends radially into the reduced diameter portion.

[0131] 22. The system of clause 9, wherein the joint section is formed of a first material, the system comprising:

[0132] an axial gap between the guard element and the joint segment, the axial gap being filled with a second material different from the first material.

[0133] 23. A method for covering a sensitive component in a downhole string, the method comprising:

[0134] positioning the sensitive component within a reduced diameter portion of the downhole string;

[0135] covering at least a portion of the sensitive component via a guard element, the guard element being arranged at least partially within the reduced diameter portion, the guard element having at least one recess and at least one coupling extension, the at least one coupling extension extending radially from an inner surface of the guard element into the reduced diameter portion;

[0136] positioning the at least one coupling extension in proximity to an aperture of a mounting segment, the aperture receiving a locking element;

[0137] fastening the at least one coupling extension to the locking element via a fastener extending through a threaded hole of the at least one coupling extension and the locking element, the fastener being arranged within the recess.

[0138] 24. The method according to clause 23, wherein a fastener axis is arranged parallel to a longitudinal axis of the joint segment.

[0139] 25. The method according to clause 23, wherein the aperture comprises a profile and the locking element comprises a mating profile, wherein the mating profile corresponds to the profile of the aperture.

[0140] The above disclosure and description of the disclosed embodiments are exemplary and explanatory only. Various changes to the details of the illustrated embodiment can be made within the scope of the appended claims without departing from the true spirit of the disclosure. The embodiments of this disclosure should only be limited by the claims and their legal equivalents.

Claims

1. A system for covering sensitive components in a downhole string, the system comprising: a junction segment in the downhole string, the junction segment including a longitudinal axis and a reduced diameter portion along the longitudinal axis; a guard element positioned on the reduced diameter portion; a mounting system adapted to axially couple the guard element to the junction segment, the mounting system comprising: a pocket in one of the junction segment and the guard element, the pocket including a shoulder; a threaded bore in the other of the junction segment and the guard element, the threaded bore oriented at least partially parallel to the longitudinal axis of the junction segment; and a fastener engaging the threaded bore through the pocket and axially coupling the guard element to the junction segment; a locking element including an elongate body portion oriented at least partially along the longitudinal axis of the junction segment and a head portion oriented at least partially perpendicular to the longitudinal axis of the junction segment, wherein the head portion forms a mating shoulder that engages the pocket to resist axial movement of the locking element.

2. The system for covering sensitive components in a downhole string of claim 1, wherein a fastener axis and the threaded bore are arranged parallel to the longitudinal axis of the junction segment.

3. The system for covering sensitive components in a downhole string of claim 1, wherein the pocket is in an outer surface of the junction segment, and the mounting system further comprises an aperture formed in the pocket, the aperture coupling the reduced diameter portion to the pocket, the aperture including a profile; and a locking element extending through the aperture, the locking element including a mating profile, wherein the mating profile corresponds to the profile of the aperture.

4. A system for covering sensitive components in a downhole string, the system comprising: a junction segment in the downhole string, the junction segment including a longitudinal axis and a reduced diameter portion along the longitudinal axis; a first guard element positioned within the reduced diameter portion, the first guard element including a first coupling extension radially extending from an inner surface of the first guard element, the first coupling extension including a threaded hole at least partially parallel to the longitudinal axis; a second guard element positioned within the reduced diameter portion, the second guard element including a second coupling extension radially extending from an inner surface of the second guard element, the second coupling extension including a hole; a mounting segment formed in the reduced diameter portion of the junction segment, the mounting segment including an aperture separated by a wall; and a fastener engaging the threaded hole of the first coupling extension and the hole of the second coupling extension. a fastener positioned within the recess, the fastener extending through the aperture in the second coupling extension and the orifice and engaging the first coupling extension, wherein the recess is formed in one of the first guard element and second guard element.

5. The system of claim 4, wherein a fastener axis is arranged parallel to the longitudinal axis of the junction segment.

6. A system for covering sensitive components in a downhole string, the system comprising: a junction segment in the downhole string, the junction segment comprising a longitudinal axis and a reduced diameter portion along the longitudinal axis; a guard element positioned within the reduced diameter portion, the guard element comprising at least one recess and at least one coupling extension radially extending from an inner surface of the guard element, the at least one coupling extension comprising an aperture; a mounting segment formed in the reduced diameter portion of the junction segment, the mounting segment comprising an orifice separated by a wall; a locking element extending through the orifice, the locking element comprising a threaded bore at least partially parallel to the longitudinal axis; and a fastener positioned within the at least one recess, the fastener extending through the aperture in the at least one coupling extension, through the orifice, and into the threaded bore of the locking element. the locking element comprising:

7. The system of claim 6, wherein, an elongated body portion oriented at least partially along the longitudinal axis of the junction segment; and a head portion oriented at least partially perpendicular to the longitudinal axis of the junction segment.

8. The system of claim 6, wherein a fastener axis is arranged parallel to the longitudinal axis of the junction segment.

9. The system of claim 6, wherein the orifice comprises a profile and the locking element comprises a mating profile, wherein the mating profile corresponds to the profile of the orifice.

10. The system of claim 6, wherein the junction segment comprises a perimeter and the guard element covers at least a portion of the perimeter of the junction segment.

11. The system of claim 6, wherein the guard element comprises at least a first guard element and a second guard element.

12. The system of claim 6, further comprising an annular shoulder on the wall, wherein a normal vector of the annular shoulder is oriented parallel to the longitudinal axis of the junction segment.

13. The system of claim 6, wherein the guard element is made of a first material and comprises at least one channel, wherein the at least one channel is filled with a second material different from the first material.

14. The system of claim 6, further comprising: a flexible mount positioned radially between the guard element and the reduced diameter portion.

15. The system of claim 6, further comprising: ​ at least a portion of a sensor in the reduced diameter portion, wherein the at least a portion of the sensor is covered by the guard element.

16. The system of claim 6, wherein the joint section is formed of a first material, the system further comprising: an axial gap between the guard element and the joint section, the axial gap filled with a second material different from the first material.

17. A method for covering a sensitive component in a downhole string, the method comprising: positioning the sensitive component within a reduced diameter portion of the downhole string; covering at least a portion of the sensitive component via a guard element, the guard element at least partially disposed within the reduced diameter portion, the guard element having at least one pocket and at least one coupling extension, the at least one coupling extension extending radially from an inner surface of the guard element into the reduced diameter portion, the at least one coupling extension comprising a bore; positioning the at least one coupling extension adjacent to an aperture of a mounting section separated by a wall, the aperture receiving a locking element; fastening the at least one coupling extension to the locking element via a fastener extending through the bore of the at least one coupling extension, the aperture, and a threaded bore of the locking element, wherein the threaded bore is at least partially parallel to a longitudinal axis of the downhole string, the fastener disposed within the at least one pocket.

18. The method of claim 17, wherein a fastener axis is arranged parallel to the longitudinal axis of the downhole string.

19. The method of claim 17, wherein the aperture comprises a profile and the locking element comprises a mating profile, wherein the mating profile corresponds to the profile of the aperture.

Images