Patent Description:
In some hydrocarbon recovery systems and/or downhole systems, electronics and/or other sensitive hardware (e.g., sometimes referred to as a tool string) may be included in a drill string. In some cases, a drill string may be exposed to both repetitive vibrations including a relatively consistent frequency and to vibratory shocks that may not be repetitive. Each of the repetitive vibrations and shock vibrations may damage and/or otherwise interfere with the 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. Some electronic devices are packaged in vibration resistant housings that are not capable of protecting the electronic devices against both the repetitive and shock vibrations. Active vibration isolation systems can isolate the electronics from harmful vibration but at added expense. <CIT> discloses a shock absorbing drill collar device consisting of two tubular members. Arranged between the two tubular members is a rubber member which is vulcanized to the adjacent walls of the tubular members. <CIT> relates to an off-bottom flow diverter assembly. <CIT> describes a joint alignment device. <CIT> describes a fluid coupling device employing a male spherical member with a fluid receiving bore and a female housing.

A lateral isolator is provided as defined in appended claim <NUM>. The lateral isolator comprises: a housing comprising an upstream end and a downstream end; an inner member comprising a pivot ring disposed within the housing; a first elastomeric package disposed between the housing and the inner member, at a position longitudinally between the pivot ring and the upstream end; and a second elastomeric package disposed between the housing and the inner member, at a position longitudinally between the pivot ring and the downstream end.

The lateral isolator comprises a centralizer sub attached at the upstream end of the housing, the centralizer sub comprising a plurality of compliant fins attached to an outer surface of the centralizer sub and being spaced radially apart from each other about a longitudinal central axis of the lateral isolator.

In some embodiments of the lateral isolator, the first elastomeric package and the second elastomeric package are configured to collectively respond to a first input force frequency range, wherein the plurality of compliant fins are configured to collectively respond to a second input force frequency range, and wherein the second input force frequency range is different than first input force frequency range.

In some embodiments of the lateral isolator, each of the compliant fins is configured such that, when a first compliant fin of the compliant fins is radially compressed, an area of an outer face of the compliant fin, which is in contact with a structure in which the lateral isolator is positioned increases to provide a nonlinear stiffening force to the lateral isolator.

In some embodiments of the lateral isolator, when the lateral isolator is disposed in a wellbore, the lateral isolator maintains a lateral isolator pressure column through a central bore of the lateral isolator that is pressure independent from a mud flow pressure column between an exterior of the lateral isolator and the wellbore.

In some embodiments of the lateral isolator, when an input force is laterally applied to the inner member in a first direction, the lateral isolator is configured such that a first reaction force opposing the input force is reacted through the first elastomeric package, a second reaction force for opposing the first reaction force is reacted through the second elastomeric package, and a fin force opposing the input force is reacted through at least one of the compliant fins.

In some embodiments of the lateral isolator, the first and second elastomeric packages are pre-compressed in an axial direction.

In some embodiments of the lateral isolator, the first and second elastomeric packages are configured to bulge and bulk load.

In some embodiments of the lateral isolator, the bulk loading is in response to a cocking movement of the inner member about the pivot ring, and wherein the bulk loading provides a soft snub rather than a direct contact.

The pivot ring comprises a polygonal profile complimentary to a polygonal profile provided within the housing, and wherein the polygonal profiles of the pivot ring and the housing are configured to provide torsional locking between the inner member and the housing.

In some embodiments of the lateral isolator, the elastomeric packages are configured such that the inner member is rotatably displaceable relative to the body.

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description.

Referring now to <FIG>, an example embodiment of a hydrocarbon recovery system (HRS), generally designated <NUM>, is shown. Although the HRS <NUM> is shown as being onshore (e.g., on land), in alternative embodiments, the HRS <NUM> can be installed in an offshore location (e.g., at sea). The HRS <NUM> generally includes a drill string, generally designated <NUM> suspended within a borehole, generally designated <NUM>. The borehole <NUM> extends substantially vertically away from the earth's surface over a vertical wellbore portion or, in some embodiments, deviates at any suitable angle from the earth's surface over a deviated or horizontal wellbore portion. In alternative operating environments, portions or substantially all of a borehole <NUM> may be vertical, deviated, horizontal, curved, and/or combinations thereof.

The drill string <NUM> includes a drill bit <NUM> at a lower end <NUM> of the drill string <NUM> and a universal bottom hole orienting (UBHO) sub <NUM> connected above the drill bit <NUM>. The UBHO sub <NUM> includes a mule shoe <NUM> configured to connect with a stinger or pulser helix <NUM> on a top side, generally designated <NUM>, of the mule shoe <NUM>. The HRS <NUM> further includes an electronics casing <NUM> incorporated within the drill string <NUM> above the UBHO sub <NUM>, for example, connected to a top side, generally designated <NUM>, of the UBHO sub <NUM>. The electronics casing <NUM> may at least partially house the stinger or pulser helix <NUM>, a lateral isolator <NUM> connected above the stinger or pulser helix <NUM>, an isolated mass <NUM> connected above the lateral isolator <NUM>, a lateral isolator <NUM> connected above the isolated mass <NUM>, and/or centralizers <NUM>. The isolated mass <NUM> can include electronic components. The HRS <NUM> includes a platform and derrick assembly, generally designated <NUM>, positioned over the borehole <NUM> at the surface. The platform and derrick assembly <NUM> includes a rotary table <NUM>, which engages a kelly <NUM> at an upper end, generally designated <NUM>, of the drill string <NUM> to impart rotation to the drill string <NUM>. The drill string <NUM> is suspended from a hook <NUM> that is attached to a traveling block. The drill string <NUM> is positioned through the kelly <NUM> and the rotary swivel <NUM> which permits rotation of the drill string <NUM> relative to the hook <NUM>. Additionally, or alternatively, a top drive system may be used to impart rotation to the drill string <NUM>.

The HRS <NUM> further includes drilling fluid <NUM> which may include a water-based mud, an oil-based mud, a gaseous drilling fluid, water, brine, gas, and/or any other suitable fluid for maintaining bore pressure and/or removing cuttings from the area surrounding the drill bit <NUM>. Some volume of drilling fluid <NUM> may be stored in a pit, generally designated <NUM>, and a pump <NUM> may deliver the drilling fluid <NUM> to the interior of the drill string <NUM> via a port in the rotary swivel <NUM>, causing the drilling fluid <NUM> to flow downwardly through the drill string <NUM>, as indicated by directional arrow <NUM>. The drilling fluid <NUM> may pass through an annular space <NUM> between the electronics casing <NUM> and each of the pulser helix <NUM>, the lateral isolator <NUM>, and/or the isolated mass <NUM> prior to exiting the UBHO sub <NUM>. After exiting the UBHO sub <NUM>, the drilling fluid <NUM> may exit the drill string <NUM> via ports in the drill bit <NUM> and be circulated upwardly through an annulus region <NUM> between the outside of the drill string <NUM> and a wall <NUM> of the borehole <NUM>, as indicated by directional arrows <NUM>. The drilling fluid <NUM> may lubricate the drill bit <NUM>, carry cuttings from the within the borehole <NUM> up to the surface as the drilling fluid <NUM> is returned to the pit <NUM> for recirculation and/or reuse, and/or create a mudcake layer (e.g., filter cake) on the walls <NUM> of the borehole <NUM>.

The drill bit <NUM> may generate vibratory forces and/or shock forces in response to encountering hard formations during the drilling operation. Although the drill bit <NUM> itself can be considered an excitation source <NUM> that provides some vibratory excitation to the drill string <NUM>, the HRS <NUM> may further include an excitation source <NUM> such as an axial excitation tool <NUM> and/or any other vibratory device configured to agitate, vibrate, shake, and/or otherwise change a position of an end of the drill string <NUM> and/or any other component of the drill string <NUM> relative to the wall <NUM> of the borehole <NUM>. In some cases, operation of such an axial excitation tool <NUM> may generate oscillatory movement of selected portions of the drill string <NUM>, so that the drill string <NUM> is less likely to become hung or otherwise prevented from advancing into and/or out of the borehole <NUM>. In some embodiments, low frequency oscillations of one or more excitation sources <NUM> may have values of about <NUM> to about <NUM>, inclusive. The term excitation source <NUM> is intended to refer to any source of the vibratory or shock forces described herein, including, but not limited to, a drill bit <NUM>, an axial excitation tool <NUM> that is purpose built to generate such forces, and/or combinations thereof. It will further be appreciated that drill bit whirl and stick slip are also primary sources of lateral shock and vibration and, hence, can also be primary sources of such lateral shock and vibration inputs.

In the embodiment of <FIG>, the HRS <NUM> further includes a communications relay <NUM> and a logging and control processor <NUM>. The communications relay <NUM> may receive information and/or data from sensors, transmitters, receivers, and/or other communicating devices that may form a portion of the isolated mass <NUM>. In some embodiments, the information is received by the communications relay <NUM> via a wired communication path through the drill string <NUM>. In other embodiments, the information is received by the communications relay <NUM> via a wireless communication path. In some embodiments, the communications relay <NUM> transmits the received information and/or data to the logging and control processor <NUM>. Additionally, or alternatively, the communications relay <NUM> can receive data and/or information from the logging and control processor <NUM>. In some embodiments, upon receiving the data and/or information, the communications relay <NUM> forwards the data and/or information to the appropriate sensor(s), transmitter(s), receiver(s), and/or other communicating devices. The isolated mass <NUM> may include measuring while drilling (MWD) devices and/or logging while drilling (LWD) devices and the isolated mass <NUM> may include multiple tools or subs and/or a single tool and/or sub. In the embodiment of <FIG>, the drill string <NUM> includes a plurality of tubing sections; that is, the drill string <NUM> is a jointed or segmented string. Alternative embodiments of drill string <NUM> can include any other suitable conveyance type, for example, coiled tubing, wireline, and/or wired drill pipe. The HRSs <NUM> that implement at least one embodiment of a lateral isolator <NUM> and/or lateral isolator <NUM> (see, e.g., <FIG>) disclosed herein may be referred to as downhole systems for isolating a component, (e.g., for isolating lateral and/or axial forces to an isolated mass <NUM>). Further, while the lateral isolator <NUM> and/or lateral isolator <NUM> disclosed herein may provide some nominal amount of axial isolation, most uses of such lateral isolators <NUM>, <NUM> will be accompanied by use of an axial isolator <NUM> disposed in series with the lateral isolators <NUM>, <NUM> along a drill string, such as drill string <NUM>, and/or along a tool string that comprises a portion of (e.g., is installed within and/or in-line with) a drill string, such as drill string <NUM>.

Referring generally to <FIG>, the lateral isolator <NUM> generally defines a longitudinally-extending flowbore <NUM> and has a central axis <NUM> with respect to which many of the components of the lateral isolator <NUM> are substantially coaxially aligned, when in a non-deflected state. The lateral isolator <NUM> generally includes a tubular housing <NUM>, a centralizer sub <NUM> connected to the housing <NUM> at a first end of the housing <NUM>, and a housing cap <NUM> connected to the housing <NUM> at a second end of the housing <NUM>. The housing <NUM> is configured to receive portions of an inner member, generally designated <NUM>, and two tubeform assemblies, generally designated <NUM>. In the example embodiment shown, the housing <NUM> comprises an interior circumferential shoulder <NUM>. A first of the two tubeform assemblies <NUM> can be, or is, retained longitudinally between the shoulder <NUM> and the housing cap <NUM>. A second of the two tubeform assemblies <NUM> can be, or is, retained longitudinally between the shoulder <NUM> and the centralizer sub <NUM>.

Referring primarily to <FIG>, <FIG>, and <FIG>, the inner member <NUM> is generally a tubular structure having a first tubular portion <NUM>, a second tubular portion <NUM>, and a tubular pivot ring <NUM>, which is connected between the first tubular portion <NUM> and the second tubular portion <NUM>. The first tubular portion <NUM> comprises an outer diameter that is substantially similar to an outer diameter of the second tubular portion <NUM>. The first tubular portion <NUM> is longer than the second tubular portion <NUM>. The pivot ring <NUM> comprises a generally polygonal exterior profile <NUM>, which is shaped, in the example embodiment shown, as a hexagonal profile having six sides <NUM> when viewed from above or below (e.g., along the central axis <NUM>). The sides <NUM> each comprise curved outer surfaces <NUM> that are configured to contact an interior shoulder surface <NUM> of the shoulder <NUM>. Further, the interior shoulder surface <NUM> comprises a shoulder profile <NUM> that is complementary to the polygonal exterior profile <NUM> of the inner member <NUM>. Accordingly, when the pivot ring <NUM> is received within the housing <NUM> and, more specifically, longitudinally within the shoulder <NUM> and in contact with the interior shoulder surface <NUM>, the inner member <NUM> is prevented from rotating angularly about the central axis <NUM> relative to the housing <NUM>. While the polygonal exterior profile <NUM> and the interior shoulder surface <NUM> each have generally hexagonal profiles, in alternative embodiments, the interior shoulder surface <NUM> and the polygonal exterior profile <NUM> can comprise any other suitable complementary shapes that, when nested together, similarly prevent relative angular rotation between the inner member <NUM> and the housing <NUM> about the central axis <NUM>, while allowing the relative movements of the inner member <NUM> relative to the housing <NUM> described elsewhere herein. It will be appreciated that the polygonal exterior profile <NUM> can be provided, in some embodiments, as having more or fewer than six sides, such as, but not limited to, pentagonal or octagonal shapes.

Even though the polygonal exterior profiles <NUM> described herein prevent relative angular movement (e.g., rotation) of the inner member <NUM> relative to the housing <NUM> about the central axis <NUM>, the inner member <NUM> is allowed to move both longitudinally relative to the housing <NUM> and/or in a pivoting or cocking motion relative to the housing <NUM>. The pivoting or cocking motion can allow, in some example embodiments, for up to and/or at least <NUM> degrees of relative deviation between an inner member central axis <NUM> of the inner member <NUM> and the central axis <NUM>, as shown in <FIG> and <FIG>. The amount of relative movement allowed between the inner member <NUM> and the housing <NUM> is limited by the presence of the tubeform assemblies <NUM>. Different amounts of relative angular deviation, both greater and smaller, between the inner member central axis <NUM> and the central axis <NUM> may be provided from the example value of <NUM> degrees provided herein.

Referring primarily to <FIG>, each tubeform assembly <NUM> comprises an inner retainer <NUM>, an outer retainer <NUM>, elastomeric package <NUM> disposed at least partially between the inner retainer <NUM> and the outer retainer <NUM>, and an end ring <NUM>. The inner retainer <NUM> is generally tubular (e.g., in the shape of a hollow cylinder) in shape and includes a central portion <NUM> comprising a substantially constant inner diameter suitable for receiving the second tubular portion <NUM> of the inner member <NUM>. The inner retainer <NUM> includes a captured lip <NUM> disposed at a first end of the central portion <NUM>. The captured lip <NUM> has an inner diameter substantially similar to the inner diameter of the central portion <NUM>, but has an outer diameter that is larger than an outer diameter of the central portion <NUM>. The inner retainer <NUM> also includes a flared end portion <NUM> disposed at a second end of the central portion <NUM>. The flared end portion <NUM> has a flared or gradually increasing inner diameter and an external diameter larger than the external diameter of the captured lip <NUM>.

The outer retainer <NUM> includes a central portion <NUM> having an outer diameter suitable for being received within the shoulder <NUM> of housing <NUM>. The outer retainer <NUM> also has an inward abutment ring <NUM> disposed at a first end of the central portion <NUM> and an outer abutment ring <NUM> disposed at a second end of the central portion <NUM>. The inward abutment ring <NUM> has an outer diameter substantially the same as the outer diameter of the central portion <NUM> but has an inner diameter that is smaller than the inner diameter of the central portion <NUM>. The outer abutment ring <NUM> has an inner diameter substantially the same as the inner diameter of the central portion <NUM> but has an outer diameter that is larger than the outer diameter of the central portion <NUM>.

The elastomeric package <NUM> is disposed, at least partially, in a space radially between inner retainer <NUM> and outer retainer <NUM>. The elastomeric package <NUM> is also disposed, at least partially, in a space longitudinally between the flared end portion <NUM> and the inward abutment ring <NUM>. Further, the elastomeric package <NUM> is disposed, at least partially, in a space radially between the inner retainer <NUM> and the housing cap <NUM>. A portion of the elastomeric package <NUM> is also disposed, at least partially, longitudinally between the captured lip <NUM> and the end ring <NUM>. The end ring <NUM> has an inner diameter configured to receive (e.g., the same size, or larger than) the first tubular portion <NUM> and an outer diameter that is smaller than than an inner diameter of the housing cap <NUM>. In this embodiment, a portion of the elastomeric package <NUM> is disposed radially between the end ring <NUM> and the housing cap <NUM>. Because the elastomeric package <NUM> is elastically deformable, the inner member <NUM> is movable relative to the housing <NUM> as a function of deforming the elastomeric package <NUM>, but the movement of the inner member <NUM> relative to the housing <NUM> is limited by the limited compressibility of the elastomeric material of the elastomeric package <NUM>, as well as the limited amount of free space into which the elastomeric material can be displaced. In this embodiment, the tubeform assemblies <NUM> are provided so that the elastomeric packages <NUM> are pre-compressed (e.g., in the axial direction), thereby maintaining a preload on the elastomer that eliminates gapping and reduces the effects of compression set. Under extreme axial loads applied to the tubeform assemblies <NUM>, the elastomer of the elastomeric packages <NUM> is allowed to bulge and fill free volume within the surrounding structure so that the elastomeric material bulk loads to control an amount of shear within the elastomeric material. This can be particularly useful when the elastomeric material comprises rubber.

Referring primarily to <FIG>, the first tubular portion <NUM> of the inner member <NUM> is connected to a movable sub <NUM>. The movable sub <NUM> is configured to receive a reduced neck portion <NUM> of the first tube portion <NUM> and a sub nut <NUM> is received within the movable sub <NUM> and configured to threadingly engage the reduced neck portion <NUM>, thereby capturing the movable sub <NUM> relative to the inner member <NUM> and ensuring that movement of the inner member <NUM> causes similar movement to the movable sub <NUM> and vice versa. The reduced neck portion <NUM> is a distal portion of the first tubular portion <NUM> having a reduced outer diameter as compared to the proximal portion of the first tubular portion <NUM>, the proximal portion of the first tubular portion <NUM> being adjacent to and/or in contact with the pivot ring <NUM>. The housing cap <NUM> comprises a bowl profile <NUM> configured to receive a guide neck <NUM> of the movable sub <NUM>, the guide neck <NUM> having an outer profile generally complementary to the bowl profile <NUM>. In this embodiment, at least a portion of the guide neck <NUM> remains received longitudinally within the housing cap <NUM>, thereby ensuring that relative longitudinal movement of the inner member <NUM> relative to the housing <NUM> does not result in the movable sub <NUM> becoming hung on an uninclined surface (e.g., a flat end surface) of the housing cap <NUM>. Also, the bowl profile <NUM> and the guide neck <NUM> have substantially similar contoured contact surfaces to work together to prevent excess or harmful cocking deviation of the inner member <NUM> relative to the housing <NUM>.

Still referring primarily to <FIG>, the centralizer sub <NUM> extends away from the housing <NUM> (e.g., in the direction of the central axis <NUM>) and comprises a carrier portion <NUM> comprising an outer diameter that is reduced, or smaller, compared to the outer diameter of the housing <NUM> and/or other portions of the centralizer sub <NUM>. The centralizer sub <NUM> further comprises compliant fins <NUM> carried by (e.g., rigidly attached to) the carrier portion <NUM>. In the example embodiment shown, the centralizer sub <NUM> includes three compliant fins <NUM> disposed about the central axis <NUM> in an evenly distributed angular array (e.g., spaced apart from each other with an angular pitch of about <NUM> degrees). The compliant fins <NUM> are configured for a directional installation relative to anticipated fluid flow along the exterior of the lateral isolator <NUM>. More specifically, each compliant fin <NUM> includes a downstream incline surface <NUM> that gradually decreases an outer diameter of the compliant fin <NUM> along the longitudinal length of the compliant fin <NUM> in the direction of fluid flow <NUM>. In contrast, a relatively blunt upstream incline surface <NUM> (e.g., having a larger angle relative to the central axis <NUM> than the downstream incline surface <NUM>) of the compliant fin <NUM> is provided. In this embodiment, the compliant fins <NUM> are constructed at least partially of elastomeric material, so that the lateral isolator <NUM> provides additional lateral and/or cocking compliance beyond the features disclosed elsewhere herein. The compliant fin <NUM> shape provides a varying load area that changes with respect to the amount of force on the face <NUM>. Under small loads, the face <NUM> has a smaller load area when compared to large loads. The face <NUM> can bulge to enable the non-linear stiffness behavior of the compliant fin <NUM>. As the compliant fin <NUM> is compressed radially, the surface area of the face <NUM> acting as a contact surface will increase due to the radial compression of the compliant fin <NUM>, thereby providing the varying, or variable, load area referenced herein.

Still referring primarily to <FIG>, the lateral isolator <NUM> is shown with an optional movable sub protector <NUM>, which is threadingly engaged to the movable sub <NUM>, and an optional centralizer sub protector <NUM>, which is threadingly engaged to the centralizer sub <NUM>. The movable sub protector <NUM> and the centralizer sub protector <NUM> can be provided on the lateral isolator <NUM> to protect the internal connection threads <NUM> of the movable sub <NUM> and the external connection threads <NUM> of the centralizer sub <NUM>, respectively, when the lateral isolator <NUM> is not yet installed within the drill string <NUM> of an HRS <NUM>.

Referring now to <FIG>, a longitudinal end view of the inner member <NUM> is shown disposed within housing <NUM>, with some components of the lateral isolator <NUM> being omitted from this view. The polygonal exterior profile <NUM> of inner member <NUM> is matched by (e.g., has an outer surface that is substantially the same size and shape as the outer surface of) a complimentary polygonal profile <NUM> of housing <NUM>.

Referring now to <FIG>, a simplified schematic representation of the lateral isolator <NUM> can be described more generally as a series spring/damper system where the elastomeric components, the elastomeric packages <NUM> and the compliant fins <NUM>, provide both spring and damping characteristics to the lateral isolator <NUM>. More specifically, the lateral isolator <NUM> is shown with kinematic connections between the unitary combination of the housing <NUM>, centralizer sub <NUM>, and housing cap <NUM> (labeled collectively as "ISOLATOR BODY" in <FIG>) and each of the inner member <NUM> and the movable sub <NUM> (labeled as "DRILL COLLAR" in <FIG>), these kinematic connections being the elastomeric package(s) <NUM> and the compliant fins <NUM>, respectively. The elastomeric packages <NUM> are shown as having a spring force component <NUM> and a damping force component <NUM>. The compliant fins <NUM> are shown as having a spring force component <NUM> and a damping force component <NUM>. Because the lateral isolator <NUM> comprises two unique sets of elastomeric components, the elastomeric packages <NUM> and the compliant fins <NUM>, the lateral isolator <NUM> can be referred to as a dual stage isolator.

Dual stage isolation can be provided by the lateral isolator <NUM> by tuning the two different sets of elastomeric components to any of a variety of performance characteristics, such as, for example, by selecting optimized stiffness and damping characteristics. For example, the dual stage isolation can be achieved by providing elastomeric packages <NUM> that are softer (e.g., have lower stiffness values) than the compliant fins <NUM>, which can be harder, or stiffer, than the elastomeric packages <NUM>. Alternatively, the dual stage isolation can be achieved by providing compliant fins <NUM> that are softer (e.g., have lower stiffness values) than the set of elastomeric packages <NUM>, which can be harder, or stiffer, than the compliant fins <NUM>. These arrangements allow for higher displacement under an aggressive, or large magnitude, force input and boosts lateral isolator <NUM> performance by more effectively mitigating shock by extending the duration of the input into the lateral isolator <NUM> system occurs. In some embodiments, stiffness of compliant fins <NUM> can be about <NUM> N/mm (<NUM>,<NUM> pounds per inch (lbs/in)) to about <NUM> N/mm (<NUM>,<NUM> lbs/in) to ensure proper operation of the dual stage isolation characteristics of the lateral isolator <NUM>. Of course, compliant fin <NUM> and elastomeric package <NUM> stiffness and geometries can be scaled or tailored to be appropriate for applications other than use with HRS <NUM>. In some cases, compliant fins <NUM> can be replaced by other compliant centralizing components, such as, for example, a drill pipe centralizer. Generally, the lateral isolator <NUM> can be scaled by using substantially the same design but with changes to material or geometry to satisfy different design constraints, such as larger or smaller ranges of frequency responsiveness or load capability.

The lateral isolator <NUM> is designed to be operated, in most circumstances, with an axial isolator, such as axial isolator <NUM>. Because axial shocks are not to be primarily handled by (e.g., absorbed and/or dissipated by) the lateral isolator <NUM>, the lateral isolator <NUM> is designed to have a high stiffness rating in the axial direction to limit strain on the elastomeric packages <NUM>, thereby increasing the service life of the elastomeric packages <NUM>. During high amplitude axial input shock events, the tubeform assemblies <NUM> are configured to allow full bulk loading in a compression region of the elastomer by capturing elastomer between the end ring <NUM> and the captured lip <NUM> and also between the flared end portion <NUM> and the inward abutment ring <NUM>. This bulk loading behavior restricts motion and keeps strain levels of the elastomeric packages <NUM> within acceptable limits.

The lateral isolator <NUM> can provide some torsional isolation and shock protection to the drill string <NUM> and/or a tool string <NUM> as well. As explained elsewhere herein, the inner member <NUM>, tubeform assemblies <NUM>, and collective isolator body (e.g., the housing <NUM>, the centralizer sub <NUM>, and the housing cap <NUM>) are all rotatably interlocked using polygonal profiles to provide torsional compliance through the elastomer region and eliminate motion across hard components. The component sizing tolerances are configured and selected to allow the largest gap to exist between the polygonal profile (e.g., <NUM>) of the inner member <NUM> and the complimentary polygonal profile (e.g., <NUM>) of the housing <NUM> to allow for torsional compliance between the downstream and upstream connections made to the lateral isolator <NUM>. As the center pivot polygon profile (e.g., <NUM>) of the pivot ring <NUM> wears (e.g., due to frictional contact with adjacent surfaces) during use, the torsional compliance provided by the lateral isolator <NUM> increases due to wearing of the polygon interface surfaces (e.g., <NUM>, <NUM>), thereby increasing torsional isolation provided by the lateral isolator <NUM> during the operational life of the lateral isolator <NUM>.

Referring now to <FIG>, a simplified force reaction diagram of a lateral isolator <NUM> in use is shown. When in use, the lateral isolator <NUM> is typically deployed in conjunction with another tool string component <NUM> connected in series along the length of the tool string <NUM>. In most applications, the tool string component <NUM> will comprise a centralizer <NUM>. The centralizer <NUM> can comprise, or be in the shape of, a plurality of radially arranged fins substantially similar to compliant fins <NUM> in shape, stiffness, and/or damping characteristics. However, the centralizer <NUM> may be shaped differently and may contact an interior wall <NUM> of a tubular component <NUM> differently as compared to how compliant fins <NUM> contact the tubular component <NUM>.

When the lateral isolator <NUM> and the tool string component <NUM> are deployed within the tubular component <NUM>, a substantially lateral input force <NUM> may be introduced (e.g., in a substantially radial direction, relative to the central axis <NUM>) to the lateral isolator <NUM> at the movable sub <NUM>. The lateral input force <NUM> is typically provided to the lateral isolator <NUM> by a component connected to the movable sub <NUM> at an opposite end from which the inner member <NUM> is connected thereto, in series along the tool string <NUM>. The lateral input force <NUM> is reacted to by an opposing fin force <NUM> that represents the interior wall <NUM> opposing the radial movement of one more compliant fins <NUM> as the compliant fins <NUM> are pressed against the interior wall <NUM> in response to the lateral input force <NUM> being transferred through the lateral isolator <NUM>. When the lateral input and fin forces <NUM>, <NUM> are of a sufficient magnitude, the inner member <NUM> pivots about the pivot ring <NUM> so as to be inclined, or cocked, relative to the rigid surrounding outer portions, such that the inner member central axis <NUM> is no longer coaxial with, or parallel to, the central axis <NUM>, thereby providing lateral bending compliance and preventing the need to accommodate such bending forces as are required to be accommodated in rigidly attached tool string components known from the prior art.

As shown, the lateral bending compliance is achieved by compressing elastomeric packages <NUM> between the inner member <NUM> and at least the housing cap <NUM>, resulting in a downstream reaction force <NUM>, and between the inner member <NUM> and at least the centralizer sub <NUM>, resulting in an upstream reaction force <NUM>. In response to the lateral input and fin forces <NUM>, <NUM>, the overall bending inputs to the tool string <NUM> can be balanced by radial movements of the centralizer <NUM> being opposed by contact with the interior wall <NUM>, thereby generating a balancing force <NUM>. <FIG> is also helpful in illustrating that, when the lateral isolator <NUM> is disposed within the tubular component <NUM> (e.g., a wellbore), the lateral isolator <NUM> defines a lateral isolator pressure column <NUM> longitudinally through the center of the lateral isolator <NUM> and a separate exterior pressure column <NUM> that is between the exterior of the lateral isolator <NUM> and the tubular component <NUM>. The lateral isolator pressure column <NUM> is pressure independent from the exterior pressure column <NUM>. Further, a fluid flow direction <NUM> within the lateral isolator pressure column <NUM> is in the same direction as the fluid flow direction <NUM> of the exterior pressure column <NUM>.

Referring now to <FIG>, a second example embodiment of a lateral isolator, generally designated <NUM>, is shown. The lateral isolator <NUM> is substantially similar to lateral isolator <NUM>, but rather than comprising the movable sub <NUM> and associated sub nut <NUM> shown and described in the lateral isolator <NUM>, the lateral isolator <NUM> comprises a movable sub <NUM> and a spanner nut <NUM>, which is disposed between the movable sub <NUM> and the housing cap <NUM>. Each of the spanner nut <NUM> and the movable sub <NUM> are configured for threadingly engaging with a threaded portion (e.g., a reduced neck portion <NUM>, see <FIG>) of the first tubular portion <NUM> of the inner member <NUM>.

In operation, the lateral isolators <NUM>, <NUM> can mitigate, or reduce, lateral shock and vibration caused by downhole drilling compared to conventional rigidly attached and/or assembled tool strings and/or drill strings, thereby preventing premature electronic and/or sensor failures caused by lateral vibrations and shock within the drill string <NUM>. The lateral isolators <NUM>, <NUM> can also mitigate, or reduce, lateral vibrations induced by drill string <NUM> whirling compared to conventional rigidly attached and/or assembled drill strings. Providing the lateral isolators <NUM>, <NUM> effectively mounts the sensitive components of the tool string within the drill string <NUM> in a manner that provides a relatively soft joint that allows cocking and lateral movement between components of the tool string <NUM> and/or the drill string <NUM> attached thereto, as opposed to being rigidly mounted and/or only providing axial vibration and shock reduction. The lateral isolators <NUM>, <NUM> provide the improved cocking and lateral movement, while high axial stiffness of the lateral isolators <NUM>, <NUM> prevents damage to the elastomeric components by limiting shear deformation of the elastomeric components. Further, the centralizer sub <NUM> and associated compliant fins <NUM> provide the tool string <NUM> and/or the drill string <NUM> stability and control, as well as additional lateral compliance characteristics for the lateral isolators <NUM>, <NUM>. The increased stability of the tool string <NUM> and/or the drill string <NUM> increases fatigue life of the system and maintains centralization of the MWD/LWD electronics.

Additionally, because the lateral isolators <NUM>, <NUM> are configured to maintain angular orientation while providing the lateral and cocking compliance, orientation and directionality of the MWD/LWD electronics are maintained, so that reference planes and direction in gyroscopes, accelerometers, and magnetometers are maintained and target locations are successfully reached. Similarly, since the angular orientations are maintained, drilling safety is improved due to the drill string being better prevented from entering off-limits regions and/or other wells. According to alternative embodiments of the disclosure, an HRS <NUM> may comprise two or more (e.g., a plurality of) lateral isolators <NUM>, <NUM> connected (e.g., in series) along the drill string <NUM> and/or the tool string <NUM>.

The lateral isolators <NUM>, <NUM> can be particularly useful in mitigating high lateral shocks to the isolated mass <NUM>. When the isolated mass <NUM> carries battery packs, the lateral isolators <NUM>, <NUM> may prevent immediate explosion of the battery packs in response to high lateral shocks. The lateral isolators <NUM>, <NUM> can also prevent fatigue in solder joints, wires, and mounts of an isolated mass <NUM>. Further, the lateral isolators <NUM>, <NUM> can prevent stress cracking of pressure barrels of a drill string and/or tool string, thereby preventing failure of the drill string and/or tool string. The lateral isolators <NUM>, <NUM> also allow an isolated mass <NUM> to survive longer in an aggressive drilling environment, where lateral shock and vibration are larger than in conservative drilling environments.

The lateral isolators <NUM>, <NUM>, when configured as dual stage isolators where one set of elastomeric components is tuned to have a first frequency response range and a second set of elastomeric components is tuned to have a second frequency response range. different from the first frequency response range, can provide a non-linear spring rate system that allows for infinite stiffness values to mitigate high frequency low amplitude inputs, as well as low frequency, high amplitude inputs. When low input events are received by the lateral isolators <NUM>, <NUM> as configured in the manner described above, the lateral isolators <NUM>, <NUM> can behave as "soft" isolators, while, when high input events are received by the lateral isolators <NUM>, <NUM>, the lateral isolators <NUM>, <NUM> can behave as "hard" isolators by asymptotically stiffening to control motion to a soft snub. Put another way, the lateral isolators <NUM>, <NUM> can, as a gradual stiffness is increased, provide a gradual stop to movements resulting from the excitation force inputs. Further, the lateral isolators <NUM>, <NUM> provide a soft joint in the tool string and/or drill string to allow bending to occur through the elastomer rather than bending metal components, thereby increasing the life span of the rigid components of the tool string and/or drill string. As described above, the lateral isolators <NUM>, <NUM> can mitigate shock and vibration in the lateral and/or cocking directions to reduce vibration and shock transmission into the electronics of an isolated mass, such as isolated mass <NUM>, or other sensitive electronics of a tool string, thereby enabling improved longevity and reliability of the electronics. The lateral isolators <NUM>, <NUM> also increase control over the operation of a drill string and/or tool string by incorporating the spring and damper system into a single component having elastomeric components. The elastomeric components effectively increase the duration of an input to the lateral isolators <NUM>, <NUM> and remove undesirable energy simultaneously to lessen the output movement from the lateral isolators <NUM>, <NUM> as compared to the input movement.

Referring now to <FIG>, a schematic illustration of a second example embodiment of a tool string, generally designated <NUM>, is shown. The tool string <NUM> includes an isolated mass <NUM> disposed in series between at least two lateral isolators <NUM>, <NUM>. An axial isolator <NUM> is disposed serially along the tool string <NUM>, axially beyond the at least two lateral isolators <NUM>, <NUM>.

Referring now to <FIG>, a schematic illustration of a third example embodiment of a tool string, generally designated <NUM>, is shown. The tool string <NUM> includes at least two lateral isolators <NUM>, <NUM>, which are disposed between an isolated mass <NUM> and an axial isolator <NUM>.

Referring now to <FIG>, a schematic illustration of a fourth example embodiment of a tool string, generally designated <NUM>, is shown. The tool string <NUM> includes a single lateral isolator <NUM>, <NUM> disposed between an isolated mass <NUM> and an axial isolator <NUM>.

Referring now to <FIG>, a schematic illustration of a fifth example embodiment of a tool string, generally designated <NUM>, is shown. The tool string <NUM> includes a single lateral isolator <NUM>, <NUM> disposed below (e.g., in the direction of the drill bit <NUM>, see <FIG>) an isolated mass <NUM>. In some such embodiments, the tool string <NUM> does not comprise an axial isolator.

Referring now to <FIG>, a schematic illustration of a sixth example embodiment of a tool string, generally designated <NUM>, is shown. The tool string <NUM> includes a directional module <NUM>, a battery <NUM>, a gamma module <NUM>, a pulser module <NUM>, a lateral isolator <NUM>,<NUM>, an axial isolator <NUM>, and a lower end <NUM>, disposed in the order listed and ending with the lower end being the component of the tool string that is closest to the drill bit (see, e.g., <NUM>, <FIG>).

Referring now to <FIG>, a graphical plot of run data during operating the tool string <NUM> of <FIG> is shown. The run data was acquired in a lateral segment in comparable run conditions. Each configuration was run five times, with data pulled from the pulser module <NUM>, gamma module <NUM>, and directional module <NUM>. Results showed favorable shock reduction with the greatest reduction being observed in the components along the tool string <NUM> that are closest to the lateral isolator <NUM>, <NUM>. The lateral isolator <NUM>, <NUM> provided the highest shock reduction near the pulser module <NUM> and the gamma module <NUM>. It is thought that the enhanced shock reduction observed at the pulser module <NUM> and the gamma module <NUM> is due to the close proximity of the lateral isolator <NUM>, <NUM> to these components. Shock reduction performance was observed to be greatest in components of the tool string <NUM> that have greater exposure to high (><NUM>) shock events typically observed adjacent the lower end <NUM> of the tool string <NUM>. The lateral isolator <NUM>, <NUM> is observed to perform incrementally better as shock inputs increase in magnitude.

Data was compiled using the start and end point of the tool string <NUM>. Runs <NUM>, <NUM>, and <NUM> were measured at the gamma module <NUM>. Runs <NUM> and <NUM> were obtained in a tool string having a standard axial isolator, while Run <NUM> was obtained in a tool string having a finned axial isolator <NUM> and lateral isolator <NUM>, <NUM>. Overall, the goal of reducing lateral shock and vibration in this series of run data was achieved. The tools performed as expected and showed a direct correlation of reducing lateral shock and vibration when a lateral isolator <NUM>, <NUM> and finned axial isolator <NUM> were paired together in a tool string. The finned axial isolator <NUM> provided a stabilized lower end <NUM>, while the lateral isolator <NUM>, <NUM> decoupled shock inputs at the lower end <NUM> from the remainder of the components of the tool string <NUM>.

Referring now to <FIG>, run data obtained from the pulser module <NUM> is shown. The run data showed an average shock reduction of approximately <NUM>%. However, the shock isolation and reduction benefit is seen in the normalized data for shock counts per hour. Results show approximately an <NUM>% reduction of shock counts greater than <NUM>. The results also confirmed that the shock isolation and reduction benefits are realized when higher shock inputs are received.

Referring now to <FIG>, run data obtained from the gamma module <NUM> is shown. The run data showed an average shock reduction of approximately <NUM>%. Like with the pulser module <NUM> data of <FIG>, the shock isolation and reduction benefits are seen in shock counts per hour. Results show approximately a <NUM>% reduction of shock counts greater than <NUM>. The results also confirmed that the shock isolation and reduction benefits are realized when higher shock inputs are received.

Referring now to <FIG>, run data obtained from the directional module <NUM> is shown. The run data showed an average shock reduction of approximately <NUM>%. The shock isolation and reduction characteristics are more attenuated (e.g., less) at the directional module <NUM> due to the lower overall shock inputs. Also, there was less run data on the directional module <NUM>, so conclusions are not as defined as the gamma module <NUM> and pulser module <NUM> run data shows in <FIG>.

Referring now to <FIG> and <FIG>, detailed shock values, counts, and reductions by run of the tool string <NUM> are provided.

It will be appreciated that the type of isolation provided by a lateral isolator <NUM>, <NUM> can be provided by a drill string level component and/or a tool string level component to reduce the transmission of lateral shocks along, and to other components of, a drill string and/or a tool string by similarly providing one or more components with a mechanism comprising at least an inner member <NUM> and a tubeform assembly <NUM>.

Claim 1:
A lateral isolator (<NUM>, <NUM>) comprising:
a tubular housing (<NUM>) comprising:
an upstream end;
a downstream end; and
an interior circumferential shoulder (<NUM>) comprising an interior shoulder surface (<NUM>), which has a shoulder profile (<NUM>);
an inner member (<NUM>) comprising:
a first tubular portion (<NUM>);
a second tubular portion (<NUM>); and
a pivot ring (<NUM>) disposed within the housing (<NUM>),
wherein the pivot ring (<NUM>) is connected between the first tubular portion (<NUM>) and the second tubular portion (<NUM>); and
wherein the pivot ring (<NUM>) comprises a polygonal profile (<NUM>) complimentary to the shoulder profile (<NUM>), the polygonal profile (<NUM>) of the pivot ring (<NUM>) and the shoulder profile (<NUM>) of the housing (<NUM>) being configured to provide torsional locking between the inner member (<NUM>) and the housing (<NUM>);
a centralizer sub (<NUM>) connected to the housing (<NUM>) at the upstream end of the housing (<NUM>), the centralizer sub (<NUM>) comprising a plurality of compliant fins (<NUM>) attached to an outer surface of the centralizer sub (<NUM>) and being spaced radially apart from each other about a longitudinal central axis (<NUM>) of the lateral isolator (<NUM>, <NUM>);
a housing cap (<NUM>) connected to the housing (<NUM>) at the downstream end of the housing (<NUM>), the housing cap (<NUM>) comprising a bowl profile (<NUM>) configured to receive a guide neck (<NUM>) of a movable sub (<NUM>), the guide neck (<NUM>) having an outer profile complementary to the bowl profile (<NUM>);
a first elastomeric package (<NUM>) disposed between the housing (<NUM>) and the inner member (<NUM>), at a position longitudinally between the pivot ring (<NUM>) and the housing cap (<NUM>); and
a second elastomeric package (<NUM>) disposed between the housing (<NUM>) and the inner member (<NUM>), at a position longitudinally between the pivot ring (<NUM>) and the centralizer sub (<NUM>).