Isolating mule shoe

Systems and methods are disclosed that include providing an isolating mule shoe having an integrated axial isolator coupled to a landing sleeve of a drill string at an upper end of the axial isolator. The axial isolator includes an elastomeric component that is coupled between a first component and a second component. The first component and the second component are configured to displace axially with respect to one another as a result of a force imparted upon the landing sleeve to provide vibration control.

BACKGROUND

In some hydrocarbon recovery systems, electronics and/or other sensitive hardware may be included in a drill string. In some cases, a drill string may be exposed to both repetitive vibrations comprising a relatively consistent frequency and vibratory shocks that alternatively may not be repetitive. Each of the repetitive vibrations and shock vibrations may damage and/or otherwise interfere with operation of the electronics, such as, but not limited to, measurement while drilling (MWD) devices and/or logging while drilling (LWD) devices, and/or any other vibration sensitive device of a drill string. While some electronic devices are packaged in vibration resistant housings, in some cases the vibration resistant housings are not capable of protecting the electronic devices against both the repetitive and shock vibrations. In some cases, active vibration isolation systems are provided to isolate the electronics from harmful vibration but the active vibration isolation systems are expensive. Further, many hydrocarbon recovery systems employ universal bottom hole orientation (UBHO) subs in combination with a complementary alignment hub in order to establish and maintain a downhole tool orientation relative to the wellbore. The alignment hub is sometimes referred to as a landing sleeve and/or a mule shoe, and the alignment hubs are generally axially rigid so that repetitive vibrations and shock vibrations are not significantly damped by the alignment hub and/or the UBHO sub.

SUMMARY

In some embodiments of the disclosure, an isolating mule shoe is disclosed as comprising: a landing sleeve; and an axial isolator coupled to the landing sleeve, the axial isolator comprising: an upper external adapter; an upper inner sleeve; an upper shear unit coupled to an outer surface of the upper inner sleeve and coupled to an inner surface of the external adapter; a lower external adapter; a lower inner sleeve axially coupled to the upper inner sleeve; and a lower shear unit coupled to an outer surface of the lower inner sleeve and coupled to an inner surface of the external adapter.

In other embodiments of the disclosure, an isolating mule shoe is disclosed as comprising: a landing sleeve; an axial isolator coupled to the landing sleeve, the axial isolator comprising: an isolator module; and a universal bottom hole orientation (UBHO) adapter axially coupled to the isolator module and configured to receive at least a portion of the isolator module within a substantially conical bore, wherein at least a portion of the isolator module received within the substantially conical bore is bonded to at least a portion of the substantially conical bore via an elastomeric material.

In yet other embodiments of the disclosure, a method of reducing vibration in a drill string is disclosed as comprising: providing an isolating mule shoe having an axial vibration damper comprising a first component, a second component, and at least one elastomeric component disposed between the first component and the second component; coupling axially the axial vibration damper to a landing sleeve of the drill string; imparting a force from the landing sleeve to the first component of the axial vibration damper; and displacing axially the second component with respect to the second component.

DETAILED DESCRIPTION

In some cases, it is desirable to provide a passive isolator for a drill string that protects electronics and other sensitive equipment from repetitive vibrations and/or shock vibrations. It may also be desirable to provide an isolator configured to axially isolate the above-described vibration sensitive components from vibrations over a large frequency range. In some cases, an isolator may be tuned and/or otherwise configured to isolate the vibration sensitive component from frequencies as low as about 1 Hz to about 50 Hz, about 5 Hz to about 25 Hz, about 10 Hz to about 20 Hz, or about 15 Hz. However, in some embodiments, the isolator may be very stiff and have a natural frequency between about 10 Hz and about 200 Hz. Accordingly, in such embodiments, the isolator may be tuned and/or otherwise configured to isolate the vibration sensitive component from frequencies higher than between about 110 Hz and about 200 Hz. In some embodiments, even though an isolator is configured to effectively isolate the above-described relatively low frequencies, the same isolators may also effectively isolate the vibration sensitive components from frequencies much higher, such as hundreds and/or even thousands of Hertz. In other words, an isolator configured to protect vibration sensitive components from low frequency vibrations may also protect vibration sensitive components from high frequency vibrations. In some embodiments of the disclosure, systems and methods are disclosed that provide an isolator comprising a passive, relatively soft (i.e. relatively long settling time) spring-mass system configured to have a natural frequency less than 0.7 times a selected anticipated excitation frequency. In some embodiments, the above-described isolator may include two or more axial displacement elements, each of which provide force transmission paths in series with each other, and each of which are axially movable to selectively alter an overall length of the isolator in response to a vibratory and/or shock input to the isolator.

Referring now toFIG. 1, a schematic view of a hydrocarbon recovery system100is illustrated. The hydrocarbon recovery system100may be onshore or offshore recovery system. The hydrocarbon recovery system100comprises a drill string102suspended within a borehole104. The drill string102comprises a drill bit106at the lower end of the drill string102and a universal bottom-hole orientation (UBHO) sub108connected above the drill bit106. The UBHO sub108comprises an isolating mule shoe200configured to connect with an axial end of a stinger or pulser helix111on a top side of the isolating mule shoe200. The hydrocarbon recovery system100further comprises an electronics casing113connected to a top side of the UBHO sub108. The electronics casing113may at least partially house the stinger or pulser helix111, electronic components112, and/or centralizers115. The hydrocarbon recovery system100comprises a platform and derrick assembly114positioned over the borehole104at the surface. The derrick assembly114comprises a rotary table116which engages a kelly118at an upper end of the drill string102to impart rotation to the drill string102. The drill string102is suspended from a hook120that is attached to a traveling block (not shown). The drill string102is positioned through the kelly118and the rotary swivel122which permits rotation of the drill string102relative to the hook120. Additionally or alternatively, a top drive system (not shown) may be used to impart rotation to the drill string102.

In some cases, the hydrocarbon recovery system100further comprises drilling fluid124which may comprise a water-based mud, an oil-based mud, a gaseous drilling fluid, water, gas, and/or any other suitable fluid for maintaining bore pressure and/or removing cuttings from the area surrounding the drill bit106. Some drilling fluid124may be stored in a pit126, and a pump128may deliver the drilling fluid124to the interior of the drill string102via a port in the rotary swivel122, causing the drilling fluid124to flow downwardly through the drill string102as indicated by directional arrow130. After exiting the UBHO sub108, the drilling fluid124may exit the drill string102via ports in the drill bit106and circulate upwardly through the annular region between the outside of the drill string102and the wall of the borehole104as indicated by directional arrows132. The drilling fluid124may lubricate the drill bit106, carry cuttings from the formation up to the surface as it is returned to the pit126for recirculation, and create a mudcake layer (e.g., filter cake) on the walls of the borehole104. In some embodiments, the hydrocarbon recovery system100may further comprise an agitator and/or any other vibratory device configured to vibrate, shake, and/or otherwise change a position of an end of the drill string102and/or any other component of the drill string102relative to the wall of the borehole104. In some cases, operation of an agitator may generate oscillatory movement of selected portions of the drill string102, so that the drill string102is less likely to become hung or otherwise prevented from advancement into and/or out of the borehole104. In some embodiments, low frequency oscillations of the agitator may have values of about 5 Hz to about 100 Hz.

The hydrocarbon recovery system100further comprises a communications relay134and a logging and control processor136. The communications relay134may receive information and/or data from sensors, transmitters, and/or receivers located within the electronic components112and/or other communicating devices. The information may be received by the communications relay134via a wired communication path through the drill string102and/or via a wireless communication path. The communications relay134may also transmit the received information and/or data to the logging and control processor136, and the communications relay134may also receive data and/or information from the logging and control processor136. Upon receiving the data and/or information, the communications relay134may forward the data and/or information to the appropriate sensor(s), transmitter(s), and/or receiver(s) of the electronic components112and/or other communicating devices. The electronic components112may comprise measuring while drilling (MWD) and/or logging while drilling (LWD) devices. The electronic components112may be provided in multiple tools or subs and/or a single tool and/or single sub. In other embodiments, different conveyance types, including, coiled tubing, wireline, wired drill pipe, and/or any other suitable conveyance type may be alternatively utilized.

Referring now toFIG. 2, a cross-sectional view of the isolating mule shoe200disposed within the UBHO sub108is shown. The isolating mule shoe200comprises a housing202, a pulser helix interface204, a wear cuff206, an alignment key208, a bottom sleeve210having an orifice212, an axial isolator214, and a UBHO adapter216. The isolating mule shoe200is configured to provide the functionality of a conventional mule shoe as well as axial vibration and/or axial shock damping functionality. In some cases, the isolating mule shoe200may comprise a landing sleeve218and a mule shoe lower220, the axial isolator214being connected axially between the landing sleeve218and the mule shoe lower220. In some cases, the landing sleeve218comprises at least a portion of the housing202that houses the pulser helix interface204, the pulser helix interface204, and the alignment key208. The mule shoe lower220comprises at least the UBHO adapter216″. In some embodiments, the landing sleeve218may comprise substantially all of a conventional mule shoe, including a UBHO adapter216′. Further, in some embodiments, the mule shoe lower220may comprise only a UBHO adapter of a conventional mule shoe that may be manufactured separately from the first conventional mule shoe and/or alternatively cut from a second conventional mule shoe. Regardless of the manner in which the components of the isolating mule shoe200are created and/or sourced, the upper end of the isolating mule shoe200may provide substantially the same fluid and/or force path connectivity and/or functionality as the upper end of a conventional mule shoe while the lower end of the isolating mule shoe200may provide substantially the same fluid and/or force path connectivity and/or functionality as the lower end of a conventional mule shoe. In the embodiment shown inFIG. 2, the landing sleeve218comprises substantially the entirety of a first conventional mule shoe. However, the lower end of the first conventional mule shoe may be machined and/or otherwise reconfigured to provide an upper adapter feature222, such as, but not limited to, a reduced diameter portion comprising threads for mating to complementary threads of the upper end of the axial isolator214. Further, in the embodiment shown inFIG. 2, the mule shoe lower220comprises substantially only a UBHO adapter of a second conventional mule shoe, and the upper end of the UBHO adapter of the second conventional mule shoe may be machined and/or otherwise reconfigured to provide a lower adapter feature224, such as, but not limited to, a reduced wall thickness portion comprising threads for mating to complementary threads of the lower end of the axial isolator214. As such, the entirety of the isolating mule shoe200may be constructed by adapting two already existing conventional mule shoes and connecting the adapted conventional mule shoes or portions thereof, axially above and axially below the axial isolator214.

Referring now toFIG. 3, a cross-sectional view of the axial isolator214of the isolating mule shoe200ofFIG. 2is shown. The axial isolator214generally comprises a central axis226with which many of the components of the axial isolator214are substantially aligned coaxially. The axial isolator214further comprises an upper inner tube228, a lower inner tube230, an upper external adapter232, a lower external adapter234, an upper shear unit236, and a lower shear unit238. The upper inner tube228comprises a substantially consistent inner bore240through which drilling fluids may pass. The upper inner tube228further comprises an upper reduced outer diameter section242and a lower reduced outer diameter section244. The lower inner tube230comprises a substantially consistent lower bore section246through which drilling fluids may pass and a relatively larger diameter upper bore section248. Generally, the lower reduced outer diameter section244of the upper inner tube228is connected by an interference fit, such as, but not limited to, a press fit to the upper bore section248of the lower inner tube230. In alternative embodiments, the lower reduced outer diameter section244of the upper inner tube228may be connected to the upper bore section248of the lower inner tube230via sets of complementary threads and/or any other suitable connection. Accordingly, axial movement of the upper inner tube228and the lower inner tube230may be substantially synchronized. The lower inner tube230further comprises a lower reduced outer diameter section250. In this embodiment, an inner surface of the upper shear unit236is attached to the upper reduced outer diameter section242of the upper inner tube228, and an inner surface of the lower shear unit238is attached to the lower reduced outer diameter section250.

In this embodiment, the shear units236,238are formed of an elastomeric material, such as, but not limited to, rubber (e.g., nature rubber) and/or nitrile. In alternative embodiments, one or more portions of the shear units236,238may comprise any other suitable elastically deformable material and/or composite structure. In yet other alternative embodiments, the shear units236,238may comprise dissimilar shear moduli so that the force required to shear one portion of the shear units236,238may be insufficient to shear another portion of the shear units236,238, so that the shear units236,238may provide a non-linear and/or a tiered response to shearing forces substantially parallel to the central axis226. By increasing a distance between the shear units236,238, the shear units236,238may increasingly prevent cocking and/or off axis alignment of the components of the axial isolator214with respect to the central axis226.

The upper external adapter232comprises an upper inner diameter section252and a lower inner diameter section254that comprises a relatively smaller inner diameter as compared to the upper inner diameter section252. An outer surface of the upper shear unit236is attached to an inner wall of the upper inner diameter section252, so that the upper inner tube228is generally movably attached to the upper external adapter232. In some embodiments, the upper shear unit236may comprise a substantially rigid ring237, shim, and/or other suitable outer component that may be used to secure the upper shear unit236to the inner wall of the upper inner diameter section252via an interference fit, such as, but not limited to, a press fit. In this embodiment, a substantial portion of the upper inner tube228is located coaxially within the lower inner diameter section254, and the amount of axial overlap between the two may vary as a function of the relative axial displacement between the two that is allowed by the upper shear unit236.

The lower external adapter234generally comprises an upper inner diameter section256, a middle inner diameter section258, and a lower inner diameter section260. The upper inner diameter section256comprises an inner diameter that is larger than the inner diameter of the middle inner diameter section258. The middle inner diameter section258comprises an inner diameter that is larger than inner diameter of the lower inner diameter section260. In this embodiment, the lower shear unit238is attached to an inner wall of the middle inner diameter section258, so that the lower inner tube230is generally movably attached to the lower external adapter234. In some embodiments, the lower shear unit238may comprise a substantially rigid ring239, shim, and/or other suitable outer component that may be used to secure the lower shear unit238to the inner wall of the middle inner diameter section258via an interference fit, such as, but not limited to, a press fit. In this embodiment, a substantial portion of the lower inner tube230is located coaxially within the middle inner diameter section258, and the amount of axial overlap between the two may vary as a function of the relative axial displacement between the two that is allowed by the lower shear unit238. Further, the upper inner diameter section256generally movably receives at least a portion of the lower inner diameter section254of the upper external adapter232so that an amount of axial overlap between the two may vary as a function of the relative axial displacement allowed by the shear units236,238.

In operation, when the axial isolator214is coupled with a mass to be isolated (i.e. electronic components112and/or more generally an isolated mass), the axial isolator214provides a relatively soft (relatively long settling time) spring mass system that operates to isolate the electronic components112from selected frequencies of vibrational perturbations. While in some embodiments, the isolated mass (i.e. the electronic components112) may weigh about 150 pounds, in alternative embodiments, the electronic components112and/or any other components that together comprise a mass to be isolated by the isolator200may comprise any other suitable weight. In particular, the upper external adapter232may receive disturbing axial input forces (e.g. compressive forces and/or tension forces) from the landing sleeve218. The force may be transferred from the upper external adapter232to the upper inner tube228via the upper shear unit236. To the extent that the upper shear unit236allows axial displacement of the upper inner tube232, the upper inner tube228and the attached lower inner tube230may be free to axially displace in response to a compressive force input until an axial mechanical interference occurs. Similarly, the lower external adapter234may receive disturbing axial input forces (e.g. compressive forces and/or tension forces) from the mule shoe lower220. The force may be transferred from the lower external adapter234to the lower inner tube230via the lower shear unit238. To the extent that the lower shear unit238allows axial displacement of the lower inner tube230, the lower inner tube230and the attached upper inner tube228may be free to axially displace in response to a compressive force input until an axial mechanical interference occurs. Flexure of the shear units236,238may result in movement of the lower external adapter234either toward or away from the electronic components112, depending on the axial direction and magnitude of the input forces. Accordingly, sufficient upward or compressive forces applied to the lower external adapter234may result in a foreshortening of an overall length of the axial isolator214and/or isolating mule shoe200. Similarly, sufficient downward or tension forces applied to the lower external adapter234may result in a lengthening of an overall length of the axial isolator214and/or isolating mule shoe200. The above-described force transfer path between the upper external adapter232and the lower external adapter234comprises two serially connected soft transfer paths, each comprising a shear unit.

Referring now toFIG. 4, a cross-sectional view of an alternative embodiment of an isolating mule shoe300is shown. The isolating mule shoe300is substantially similar to the isolating mule shoe200but with a primary difference being that the isolating mule shoe300comprises two axial isolators214connected to each other serially and between the landing sleeve218and the mule shoe lower220.

Referring now toFIG. 5, a cross-sectional view of an alternative embodiment of an isolating mule shoe400is shown. The isolating mule shoe400is substantially similar to the isolating mule shoe200but with a primary difference being that the isolating mule shoe400comprises three axial isolators214connected to each other serially and between the landing sleeve218and the mule shoe lower220.

Referring now toFIG. 6, a cross-sectional view of an alternative embodiment of an isolating mule shoe500is shown. The isolating mule shoe500is substantially similar to the isolating mule shoe200but with a primary difference being that the isolating mule shoe500comprises a landing sleeve218constructed of an existing conventional mule shoe, including a UBHO adapter216′ while the mule shoe lower220comprises a newly created UBHO adapter216″′ that was not cut from and/or separated from an already existing conventional mule shoe. Instead, the UBHO adapter216″′ may be different from the UBHO adapter216′ and the mule shoe lower220may generally comprise new components.

Referring now toFIG. 7, a cross-sectional view of an alternative embodiment of an isolating mule shoe600is shown. The isolating mule shoe600is substantially similar to the isolating mule shoe500but with a primary difference being that the isolating mule shoe600comprises two axial isolators214connected to each other serially and between the landing sleeve218and the mule shoe lower220.

Referring now toFIG. 8, a cross-sectional view of an alternative embodiment of an isolating mule shoe700is shown. The isolating mule shoe700is substantially similar to the isolating mule shoe500but with a primary difference being that the isolating mule shoe700comprises three axial isolators214connected to each other serially and between the landing sleeve218and the mule shoe lower220.

Referring now toFIGS. 9A-9C, cutaway views of an alternative embodiment of an axial isolator800are shown with the axial isolator800in a maximum compressed state, a relaxed state, and a maximum extended and/or tension state, respectively. The axial isolator800is substantially similar to axial isolator214and comprises an upper inner tube802, a lower inner tube804, an upper external adapter806, a lower external adapter808, an upper shear unit810, and a lower shear unit812. Similar to the shear units236,238, the upper shear unit810and the lower shear unit812comprise substantially rigid rings811,813, respectively, that may be used to secure the upper shear unit810to an inner wall of the upper external adapter806and to secure the lower shear unit812to an inner wall of the lower external adapter808via an interference fit, such as, but not limited to, a press fit. A plurality of concavities814are located on an exterior surface of the upper external adapter806, and a plurality of corresponding longitudinal channels816are located on an interior surface of the lower external adapter808. The concavities814are each configured to receive a cylindrical pin818in a manner that substantially retains a longitudinal position of the pin818relative to the upper external adapter806. The longitudinal channels816are each configured to receive at least a portion of a cylindrical pin818, so that pins818are disposed between the lower portion of the upper external adapter806and the upper portion of the lower external adapter808when the lower portion of the upper external adapter806is received within the upper portion of the lower external adapter808. When the pins818are disposed between the lower portion of the upper external adapter806and the upper portion of the lower external adapter808, within the concavities814, and within the channels816, the pins818serve to prevent axial rotation of the upper external adapter806relative to the lower external adapter808while allowing longitudinal displacement of the upper external adapter806relative to the lower external adapter808. In some embodiments, a flexible and/or biased stop820may be carried in a concavity814and configured to engage a wall of the lower external adapter808to restrict removal of the upper external adapter806from the lower external adapter808.

Referring now toFIG. 10, a cross-sectional view of an alternative embodiment of an isolating mule shoe900is shown. The isolating mule shoe900is substantially similar to the isolating mule shoe200in that the isolating mule shoe900includes a housing902, a pulser helix interface904, a wear cuff906, an alignment key908, a bottom sleeve910having an orifice912, an axial isolator914having an isolator module915and a universal bottom hole orientation (UBHO) adapter916. In some embodiments, the isolating mule shoe900comprises a landing sleeve918that comprises at least a portion of the housing902that houses the pulser helix interface904, the pulser helix interface904, the alignment key908, and the bottom sleeve910. In some embodiments, the isolating mule shoe900also comprises a mule shoe lower920that comprises at least the UBHO adapter916. Further, it will be appreciated that the isolating mule shoe900may also be used in the UBHO sub108in a substantially similar fashion to the isolating mule shoe200. While the isolating mule shoe900is configured to provide the functionality of a conventional mule shoe as well as axial vibration and/or axial shock damping functionality substantially similarly to the isolating mule shoe200, the main difference between the isolating mule shoe900and the isolating mule shoe200is that the axial isolator914incorporates the UBHO adapter916of the isolating mule shoe900. The isolating module915and the UBHO adapter916are joined (i.e. bonded together) to form a substantially single component which may result in the axial isolator914and/or the isolating mule shoe900having a much more rigid and/or stiffer construction. Accordingly, the isolator module915and the UBHO adapter916are connected axially to the landing sleeve918such that the isolator module915is disposed between the landing sleeve918and the UBHO adapter916. To join the axial isolator914to landing sleeve918, a lower end of the landing sleeve918may comprise an upper adapter feature922, such as, but not limited to, a reduced diameter portion comprising threads for mating to complementary threads of an upper end of the isolator module915of the axial isolator914. Alternatively, the upper adapter feature922may comprise a reduced diameter portion for press-fitting into a complementary upper end of the isolator module915of the axial isolator914.

Referring now toFIG. 11, a cross-sectional view of the axial isolator914of the isolating mule shoe900ofFIG. 10is shown. The axial isolator914generally comprises a central axis924with which many of the components of the axial isolator914, such as the isolator module915and the UBHO adapter916, are substantially coaxially aligned. The isolator module915includes an upper end925that comprises a receiving portion926having a recess for receiving the upper adapter feature922of the landing sleeve918. The receiving portion926also comprises complementary threads to the upper adapter feature922so that the isolator module915may be threaded onto the upper adapter feature922of the landing sleeve918. The isolator module915comprises a substantially conical central bore928that extends from the receiving portion926and terminates at a substantially cylindrical central bore930that extends between a lower end of the substantially conical central bore928to a lower end927of the isolator module915.

The isolator module915also includes an outer surface929. In some embodiments, the outer surface929may comprise a substantially similar diameter to a largest outer diameter of the landing sleeve918. However, in other embodiments, the outer surface929may comprise a diameter that can be accepted by the UBHO sub108. The isolator module915also includes an outer conical surface932and a substantially cylindrical outer surface934having a reduced diameter relative to the outer surface929. The substantially cylindrical outer surface934extends from the lower end927of the isolator module915and terminates at the outer conical surface932. The substantially cylindrical outer surface934may be substantially concentric with the substantially cylindrical central bore930. In some embodiments, the substantially cylindrical outer surface934comprises a substantially similar length as measured along the central axis924as the substantially cylindrical central bore930. However, in other embodiments, the substantially cylindrical outer surface934may not extend from the lower end927as far as the substantially cylindrical central bore930extends as measured along the central axis924. In some embodiments, the outer conical surface932may extend between the substantially cylindrical outer surface934and the outer surface929. However, in other embodiments, the outer conical surface932may extend between the substantially cylindrical outer surface934and other geometric features, including, but not limited to, a recess931.

The UBHO adapter916includes an outer surface941. In some embodiments, the outer surface941may comprise a substantially similar diameter to the outer surface929of the axial isolator914and/or the largest outer diameter of the landing sleeve918. The UBHO adapter916includes a substantially conical counterbore942and a substantially cylindrical counterbore944. The substantially conical counterbore942extends from an upper end of the UBHO adapter916and terminates at an upper end of the substantially cylindrical counterbore944. The substantially conical counterbore942may be configured at a complementary angle to the outer conical surface932with respect to the central axis924. The substantially conical counterbore942may also be configured to receive at least a portion of the outer conical surface932, while the substantially cylindrical counterbore944is configured to receive at least a portion of the substantially cylindrical outer surface934of the isolator module915. The UBHO adapter916also includes a first enlarged central bore946and a second enlarged central bore948that have a substantially cylindrical bore shape. The first enlarged central bore946extends from a lower end of the substantially cylindrical counterbore944and has a larger diameter than the substantially cylindrical counterbore944. The second enlarged central bore948extends from a lower end of the first enlarged central bore946through the remainder of the UBHO adapter916and has a larger diameter than the first enlarged central bore946.

Generally, the isolator module915and the UBHO adapter916of the axial isolator914of the isolating mule shoe900are joined together to form a substantially single component. More specifically, the isolator module915and the UBHO adapter916are bonded together by applying an elastomeric material940between at least the outer conical surface932of the isolator module915and the substantially conical counterbore942of the UBHO adapter916. In some embodiments, the elastomeric material940may also be applied between the substantially cylindrical outer surface934of the isolator module915and the substantially cylindrical counterbore944of the UBHO adapter916to bond the isolator module915to the UBHO adapter916. The elastomeric material940may include, but is not limited to, rubber (e.g., natural rubber) and/or nitrile. In alternative embodiments, the elastomeric material940may comprise any other suitable elastically deformable material and/or composite structure capable of bonding the isolator module915to the UBHO adapter916.

The isolator module915and the UBHO adapter916also include a plurality of catch tabs952. The catch tabs952are generally configured to restrict rotation between the isolator module915and the UBHO adapter916. In some embodiments, the isolator module915and the UBHO adapter916may use three catch tabs952. In alternative embodiments, more or fewer catch tabs952may be used. Each catch tab952includes a key954disposed at each of a lower end and an upper end of the catch tab952, an inner surface956, and an outer surface958. The catch tabs952may generally form a substantially U-shaped profile, such that the keys954extend inward from the inner surface956towards the central axis924at each of the upper end and the lower end of the catch tab952. The catch tab952may extend over at least a portion of the isolator module915and the UBHO adapter916. For each of the plurality of catch tabs952, the isolator module915and the UBHO adapter916may each comprise a key slot936,950and recessed surface937,951, respectively, for receiving the catch tab954. More specifically, the isolator module915includes a key slot936for receiving the key954of the upper end of the catch tab952and the UBHO adapter916includes a key slot950for receiving the key954of the lower end of the catch tab952. Additionally, the isolator module915includes a recessed surface937that is configured to abut a portion of the inner surface956of the catch tab952, and the UBHO adapter916includes a recessed surface951that also is configured to abut a portion of the inner surface956of the catch tab952. The recessed surfaces937,951are configured at a depth such that the outer surface958of the catch tab952does not extend further from the central axis924than either of the outer surfaces929,941of the isolator module915and the UBHO adapter, respectively.

The isolator module915also includes a fastener hole938that is configured to receive a fastener960that holds each catch tab952to the isolator module915. Additionally, each of the key slots950in the UBHO adapter916may be larger than the key954at the lower end of the catch tab952such that the key954at the lower end of the catch tab952may slide within the key slot950of the UBHO adapter916to allow a longitudinal displacement of the UBHO adapter916along the central axis924with respect to each of the isolator module915and the catch tabs952. In alternative embodiments, the UBHO adapter916may include the fastener hole938that is configured to receive a fastener960that holds each catch tab952to the UBHO adapter916. Additionally, in such alternative embodiments, each of the key slots936in the isolator module915may be larger than the key954at the upper end of the catch tab952such that the key954at the upper end of the catch tab952may slide within the key slot936of the isolator module915to allow a longitudinal displacement of the isolator module915along the central axis924with respect to each of the UBHO adapter916and the catch tabs952. It will be appreciated that the fastener960may comprise a screw, a pin and retaining ring, a weld, a rivet, or any other suitable fastening device capable of fastening the catch tabs952to either of the isolator module915and the UBHO adapter916.

In operation, when the axial isolator914is coupled with a mass to be isolated (i.e. electronic components112and/or more generally an isolated mass), the isolator module915and the UBHO adapter916bonded together by the elastomeric material940to form the axial isolator914, provide a relatively soft (relatively long settling time) spring mass system that operates to isolate the electronic components112from selected frequencies of vibrational perturbations. More specifically, the isolator module915may receive disturbing axial input forces (e.g. compressive forces and/or tension forces) from the landing sleeve918. The force may be transferred from the isolator module915through the elastomeric material940to the UBHO adapter916. To the extent that the isolator module915allows axial displacement of the UBHO adapter916as described herein, the UBHO adapter916may be free to axially displace in response to a compressive force input until an axial mechanical interference occurs (via the keys954of the catch tabs952and the key slots936,950). Similarly, the isolator module915may receive disturbing axial input forces (e.g. compressive forces and/or tension forces) from the UBHO adapter916. The force may be transferred from the UBHO adapter916through the elastomeric material940to the isolator module915. Flexure of the elastomeric material940may result in movement of the UBHO adapter916either toward or away from the isolator module915and consequently the electronic components112, depending on the axial direction and magnitude of the input forces. Accordingly, sufficient upward or compressive forces may result in a foreshortening of an overall length of the isolating mule shoe900. Similarly, sufficient downward or tension forces may result in a lengthening of an overall length of the isolating mule shoe900.

Other embodiments of the current invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. Thus, the foregoing specification is considered merely exemplary of the current invention with the true scope thereof being defined by the following claims.