Patent Description:
The barite can also adversely affect the setting tool. In particular, the debris-laden drilling fluid has the tendency to deposit debris into the workings of the tool's setting mechanisms, which interferes with the actuation of the setting of the liner hanger. Additionally, drilling fluid is traditionally used as the working fluid to pressurize a hydraulic setting cylinder of the liner hanger to set the slips. When such debris-laden fluid is used, there is an increased potential to foul the setting tool and the internal pressure volume of the liner hanger.

Although existing techniques may be useful and effective, the subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth. An example of a hydraulically operated setting tool is disclosed in document <CIT>.

According to the present disclosure, a setting tool is used on tubing and is activated by applied tubing pressure behind a deployed plug to set a liner hanger in a borehole. The liner hanger has a hanger bore with at least one inlet port. The at least on inlet port is disposed in fluid communication with a hydraulic setting mechanism for the liner hanger. The setting tool comprises: a tool body, a bonnet, an actuator piston, a check valve, and an actuator seat.

The tool body is disposed on the tubing and has a tool bore for borehole fluid. A stinger portion of the tool body is configured to seal inside the hanger bore and has at least one outlet port, which is disposed in fluid communication with the at least one inlet port. The bonnet is disposed on the tool body and contains a first volume configured to hold an activation fluid separate from the borehole fluid.

The actuator piston is disposed in the tool bore and has a second volume defined therewith. The second volume is configured to hold the actuation fluid, and the at least one outlet port communicates the second volume with the at least one inlet port of the hanger. The check valve is disposed on the tool body and is configured to communicate the actuation fluid from the first volume to the second volume.

The actuator seat is associated with the actuator piston and is configured to engage the deployed plug. The actuator piston is configured to move in response to the applied tubing pressure behind the deployed plug engaged in the actuator seat. In response to the movement, the actuator piston is configured to intensify the applied tubing pressure on the actuation fluid in the second volume to the hydraulic setting mechanism for the liner hanger.

According to the present disclosure, a method of setting a liner hanger in a borehole is disclosed. The liner hanger has a hydraulic setting mechanism. The method comprises: running the liner hanger into position in the borehole by using a setting tool disposed on tubing, the setting tool having a first volume with an actuation fluid separate from the borehole fluid, the setting tool having an actuator piston with a second volume for the actuation fluid; balancing pressure in the second volume to hydrostatic pressure in the borehole by drawing the actuation fluid from the first volume to the second volume; engaging a plug in the tubing on an actuator seat in the setting tool; applying tubing pressure behind the engaged plug in the actuator seat; moving the actuator piston in the setting tool in response to the applied tubing pressure behind the engaged plug; and intensifying the applied tubing pressure to an intensified pressure of the actuation fluid in the second volume of the actuator piston and communicating the intensified pressure to the hydraulic setting mechanism of the liner hanger.

The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.

<FIG> illustrates a schematic view of a setting tool <NUM> deploying and setting a liner hanger <NUM> according to the present disclosure. As shown in <FIG>, a borehole <NUM> has casing <NUM> in which the liner hanger <NUM> is being deployed with the setting tool <NUM> to hang a liner <NUM>.

The setting tool <NUM> is connected to a running string <NUM> from the surface/rig deck/rig drawworks or the like. The running string <NUM> is run through a wellhead <NUM> and runs in the liner <NUM> and the liner hanger <NUM> through the casing <NUM>. When the proper depth is reached, the setting tool <NUM> activates the liner hanger <NUM> by setting slips <NUM> and a packing element <NUM> so the liner <NUM> extends into the open borehole <NUM>. The setting tool <NUM> of the present disclosure allows the liner hanger <NUM> to be run and set in downhole environments having a heavy, debris-laden drilling fluid, which would typically interfere with setting the liner hanger <NUM> as noted above. As shown in <FIG>, after setting the liner <NUM> and hanger <NUM>, the setting tool (<NUM>) is released from the liner hanger system so additional operations can follow, such as cementing the liner <NUM> in the open borehole <NUM>.

<FIG> illustrates a cross-sectional view of the setting tool <NUM> according to the present disclosure for deploying and setting a liner hanger <NUM>. Briefly, the liner hanger <NUM> includes a mandrel <NUM> having a flow bore <NUM> therethrough. A hydraulic setting piston <NUM> (or other hydraulic setting mechanism) on the mandrel <NUM> can be hydraulically activated by fluid communication through a flow port <NUM> in the mandrel <NUM>. The activated piston <NUM> pushes slips <NUM> on the mandrel <NUM> against cones <NUM> so that the slips <NUM> can engage inside the casing <NUM>. As also shown, the hanger <NUM> has a polished bore receptacle <NUM> attached to the upper end of the mandrel <NUM>. Although not shown in <FIG>, the downhole end of the liner hanger <NUM> supports a liner (<NUM>).

Briefly, the setting tool <NUM> includes a body <NUM> having a flow bore <NUM> therethrough from an uphole end <NUM> to a downhole end <NUM>. As is typical but now shown, the uphole end <NUM> connects to a tubing string for running the setting tool <NUM> and liner hanger <NUM>. The downhole end <NUM> can have additional tubing that includes a coupler for attaching additional component and that includes a pickup spacer (not shown) for removing components of the setting tool <NUM> from inside the hanger <NUM> during retrieval as discussed below. The flow bore <NUM> allows running fluid to pass through the setting tool <NUM> during run-in operations so that circulation can be provided as the liner (<NUM>) and hanger <NUM> are run through the borehole (<NUM>).

A stinger portion of the tool body <NUM> uses a pack-off assembly <NUM> to seal inside the hanger bore <NUM> so at least one outlet port (not labelled in <FIG>) on the tool body <NUM>/pack-off assembly <NUM> is disposed in fluid communication with at least one inlet port <NUM> of the liner hanger's hydraulic setting piston <NUM>.

In addition to these elements, the setting tool <NUM> includes a floating junk bonnet <NUM>, a packer actuator <NUM>, a release mechanism <NUM>, a locking mechanism <NUM>, a slick stinger actuator <NUM>, a pressure-balancing check valve assembly (i.e., balancing check valve <NUM>), and an over-pressure venting assembly (i.e., venting valve <NUM>).

The floating junk bonnet <NUM> is disposed on the tool body <NUM> and defines a first reserve volume <NUM> configured to hold an activation fluid separate and different from the borehole fluid. The floating junk bonnet <NUM> prevents drilling fluid from being introduced in to an annular area of the inner bore <NUM> of the liner hanger mandrel <NUM>/polished bore receptacle <NUM> and the outside surface of the setting tool's components. In conjunction with the floating junk bonnet <NUM>, the pack-off assembly <NUM> isolates the hydraulic setting port <NUM> of the liner hanger <NUM> from the drilling fluids above and below it. The fluid above the pack-off assembly <NUM> is isolated from drilling fluid by the bonnet <NUM>, and pack-off seals 99a-b and 99c-d on a body <NUM> of the pack-off assembly <NUM> isolates the setting port <NUM>. This is part of the debris exclusion achieved by the setting tool <NUM>.

Looking at further details of the setting tool <NUM>, <FIG> illustrate cross-sectional views of detailed portions of the setting tool <NUM>, including the locking mechanism <NUM>, the actuator <NUM>, portion of the pack-off assembly <NUM>, the balancing check valve <NUM>, and the venting valve <NUM> relative to the liner hanger <NUM> in the casing <NUM>. The setting tool <NUM> includes debris exclusion feature, pressure-intensifying features, and pressure-balancing features.

The locking mechanism <NUM> of the setting tool <NUM> allows for high circulation rates without wear or premature setting of the liner hanger <NUM>. In particular, the setting tool <NUM> can withstand high-flow and circulation rates because the locking mechanism <NUM> prevents any unintentional movement of the actuator piston <NUM> until the system is unlocked and it is desired to set the system. Using of the locking mechanism <NUM>, the setting tool <NUM> can also withstand open-hole pack-off situations where circulation flow is suddenly stopped and wellbore pressure increases. The pressure increase without the locking mechanism <NUM> in place could cause the actuator piston <NUM> to actuate due to the differential piston surfaces that are on the actuator piston <NUM>. With the locking mechanism <NUM> in place, however, the actuator piston <NUM> is held in place to internal pressures well above <NUM>,<NUM> psi (<NUM>,<NUM> kPa). Pack-off pressure is not allowed to achieve such a magnitude because well formation damage would likely occur.

The slick stinger actuator <NUM> includes an actuator seat <NUM> and an actuator piston <NUM> disposed in the tool bore <NUM>. The actuator seat <NUM> is associated with the actuator piston <NUM> and is configured to engage the deployed plug B. The actuator piston <NUM> has a second (tool) volume <NUM> configured to hold the actuation fluid. The outlet ports <NUM>, <NUM> on the tool body <NUM>/pack-off body <NUM> communicate the tool volume <NUM> with the inlet port(s) <NUM> of the hanger <NUM>.

During general operation disclosed in more detail below, the setting tool <NUM> runs the liner hanger <NUM> to depth in the casing <NUM>. The actuation fluid from the reserve volume <NUM> of the bonnet (<NUM>) is drawn through the balancing check valve <NUM> to the tool volume <NUM> to balance pressure inside the setting tool <NUM> with the increasing hydrostatic pressure. The check valve <NUM> disposed on the tool body <NUM> is configured to communicate the actuation fluid from the reserve volume <NUM> of the bonnet <NUM> to the tool volume <NUM>, but to prevent reverse communication.

In this way, the balancing check valve <NUM> is employed to allow for a hydrostatic response of the floating junk bonnet <NUM> to transfer hydrostatic pressure to the tool volume <NUM> of the tool <NUM>, which in turn communicates with an isolated annular volume <NUM> of the pack-off assembly <NUM>. This ensures that the pressure effect of the drilling fluid weight and depth are not a pressure/load factor that must be overcome with applied setting pressure from the setting tool <NUM> for the liner hanger <NUM>. Thus, the tool <NUM> can become pressure-balanced to the hydrostatic pressure. As the setting tool <NUM> and liner hanger <NUM> are run in hole to depth, the effect of the hydrostatic pressure equalizes all internal and external components and features without the introduction of debris and weighted drilling fluids.

When ready to set the liner hanger <NUM>, operators deploy a plug (e.g., drop ball B) down the tubing string to the seat <NUM> of the actuator <NUM>. Tubing pressure is applied behind the seated plug B, and the locking mechanism <NUM> is unlocked. Then, the actuator piston <NUM> is sheared free and is moved. The actuator piston <NUM> in response to the movement intensifies the applied tubing pressure on the actuation fluid in the tool volume <NUM> communicated to the hydraulic setting piston <NUM> for the liner hanger <NUM>. This allows the setting slips <NUM> of the liner hanger <NUM> to engage inside the casing <NUM>.

Having a general understanding of the setting tool <NUM> and its operation, some of the benefits are now noted. For instance, the setting tool <NUM> can be particularly useful for deploying and setting the liner hanger <NUM> in downhole environments having a heavy, debris-laden drilling fluid, such as <NUM> lbf/gal (ppg) (i.e., <NUM>/L). As noted previously, a major weighting component in the drilling fluid can be barite, which has the tendency to sag or deposit in low flow velocity and low-pressure gradient areas within the fluid column.

The setting tool <NUM> of the present disclosure can mitigate issues encountered when setting the liner hanger <NUM> in such an environment. In particular, the setting tool <NUM> can overcome the resistance caused by deposits that accumulate in areas around the hydraulic setting piston <NUM> used to set the slips <NUM> of the hanger <NUM>. This disclosed setting tool <NUM> provides the required actuation pressure from the setting tool <NUM> to move and set the slips <NUM> by intensifying the pressure applied by the tubing pressure behind the seated plug B. Additionally, the inner workings of the setting tool's setting mechanism are kept free of the debris-laden drilling fluid to mitigate interference of the fluid with the actuation of the setting of the liner hanger <NUM> and to avoid fouling the setting tool <NUM> and the internal pressure volume <NUM> of the liner hanger <NUM>.

Overall, the disclosed setting tool <NUM> minimizes contact with the drilling fluid, which reduces operational risk for setting the liner hanger <NUM> and potential non-productive time (NPT). As will be appreciated, the liner hanger <NUM> will be exposed externally to the drilling fluid, but the internal actuation fluid and the means to deliver the pressurize fluid via the setting tool <NUM> are not contaminated or compromised by detrimental debris.

Additional debris exclusion for the setting tool <NUM> is achieved by isolating the actuator piston <NUM>, which is part of the slick stinger <NUM> of the setting tool <NUM>. The slick stinger's piston <NUM> acts as a sealing sleeve that provides debris and pressure isolation during cementing operations during the liner hanger <NUM> installation. The slick stinger actuator <NUM> provides pressure control while transitioning to a packer setting position after cementing. However, prior to any of these functions, the slick stinger actuator <NUM> houses setting mechanisms required to actuate and provide isolated setting pressure to the hydraulic setting piston <NUM> of the liner hanger <NUM>.

The actuator piston <NUM> in the slick stinger actuator <NUM> is isolated from the drilling fluid by seals 85a-b. In this way, the actuator piston <NUM> can prevent the drilling fluid from being introduced into the clean fluid inside the tool volume <NUM>. The clean setting fluid, which is used as part of the fluid volume from the pack-off assembly <NUM>, is fed from the balancing check valve <NUM>. The setting fluid is completely isolated from external dirty fluids, and only clean fluids are introduced into the liner hanger setting port <NUM> and hydraulic chamber <NUM> of the hydraulic setting piston <NUM> during the setting operation.

The disclosed setting tool <NUM> also excludes annular wellbore fluids by using the floating junk bonnet <NUM> and by isolating the tool volume <NUM> using the pack-off assembly <NUM>. Additionally, to exclude debris, the intensifying actuator piston <NUM> uses clean fluid from the volumes <NUM>, <NUM> of the bonnet <NUM> and the actuation mechanism. The actuator piston <NUM> does not introduce contaminated, dirty wellbore fluids into the hydraulic setting piston <NUM> of the liner hanger <NUM>.

The disclosed setting tool <NUM> is pressure-balancing because the setting tool <NUM> is always hydrostatically balanced via the balancing check valve <NUM> on the pack-off assembly <NUM>. This ensures that only relative pressures above the hydrostatic pressure reference may be applied to set the liner hanger <NUM>.

In one configuration, the intensifying actuator piston <NUM> of the setting tool <NUM> can provide a power ratio of <NUM> to <NUM>, multiplying the applied tubing pressure by almost <NUM> time to produce a setting pressure that provides a large setting force to push through debris-laden environment to set the slips <NUM> of the liner hanger <NUM>. In one example, an applied tubing pressure from the surface of <NUM>,<NUM> psi (<NUM>,<NUM> kPa) against the seated plug B in the actuator seat <NUM> relates to an applied setting pressure of about <NUM>,<NUM> psi (<NUM>,<NUM> kPa) to the hydraulic setting piston <NUM> of the liner hanger <NUM>.

<FIG> illustrate cross-sectional views of detailed portions of the disclosed setting tool <NUM>. These views are similar to those disclosed above with reference to <FIG>. In this embodiment, the actuator <NUM> is shown with the locking mechanism <NUM>. Shown without a ball engaged in <FIG>, the seat <NUM> is held uphole by the locking mechanism <NUM>. Shown with the ball engaged in <FIG>, the seat <NUM> is shifted downhole when the locking mechanism <NUM> is released. In contrast to the configuration in <FIG>, the piston <NUM> of the actuator <NUM> disposed in the bore <NUM> of the tool body <NUM> is not arranged to engage an uphole shear pin (88a; <FIG>) for a secondary pressure relief system of the tool volume <NUM> discussed in more detail below.

<FIG> illustrates a process <NUM> for running in and setting the liner hanger <NUM> with the setting tool <NUM> of the present disclosure. Initially, the setting tool <NUM> is arranged (sealed and locked) in the liner hanger <NUM>, the bonnet <NUM> has its volume filled with clean actuation fluid, etc. The liner hanger <NUM> is then run into position in the borehole using the setting tool <NUM> disposed on tubing. During run in, pressure in the setting tool's volume <NUM> is balanced to hydrostatic pressure in the borehole by drawing the actuation fluid from the reserve volume <NUM> of the bonnet <NUM> to the tool volume <NUM> of the tool <NUM> (Block <NUM>).

Once the setting tool <NUM> runs in the liner hanger <NUM> to depth, a setting ball B is dropped to the release mechanism <NUM> of the setting tool <NUM> (Block <NUM>). The setting tool <NUM> is then unlocked using tubing pressure against the dropped ball B seated in a first seat of the release mechanism <NUM> (Block <NUM>). <FIG> and <FIG>discussed below show details of this first stage of operation.

With the ball B expelled from the release mechanism <NUM>, the ball B reaches a second seat <NUM> of the actuator <NUM> (Block <NUM>), and pressure is applied to unlock a locking mechanism <NUM> holding the seat <NUM> (Block <NUM>). <FIG> shows details of this second stage of operation. Once the seat <NUM> is unlocked, tubing pressure against the ball B seated in the actuator seat <NUM> can start to shear the floating actuator piston <NUM> of the actuator <NUM> free (Block <NUM>).

Operation of the setting tool <NUM> can then follow a normal stage of operation (Blocks <NUM>). <FIG> show details of this stage of operation. Tubing pressure is increased behind the engaged plug B in the actuator seat <NUM>, and the actuator piston <NUM> is moved in the setting tool <NUM> in response to the applied tubing pressure behind the engaged plug B. The actuator piston <NUM> shears free (Block <NUM>). Movement of the actuator piston <NUM> intensifies the applied tubing pressure to an intensified pressure of the actuation fluid in the tool volume <NUM>, and this intensified pressure is communicated to the hydraulic setting piston <NUM> of the liner hanger <NUM> (Block <NUM>).

When successful, the liner hanger <NUM> is set in the casing <NUM> by actuating the hydraulic setting piston <NUM> of the liner hanger <NUM> using the intensified pressure (Block <NUM>). When setting of the liner hanger <NUM> is successful in the end, then further stages of operation can follow in which cementing darts are dropped and a packer of the liner hanger system is set (Block <NUM>). Once operations complete, a releasable connection <NUM> on the setting tool <NUM> is released from inside the liner hanger <NUM>, and the setting tool <NUM> is retrieved from the liner hanger <NUM> set in the casing <NUM> (Block <NUM>).

Should normal operation be unsuccessful, operation of the setting tool <NUM> can then follow an alternative stage of operation in which the setting tool is reset and actuation is reattempted (Blocks <NUM>, <NUM>). Again, <FIG> show details related to this alternative stage. If setting operations fail, operation of the setting tool <NUM> can follow a retrieval plan to remove the tool <NUM> and liner hanger <NUM> (Block <NUM>). <FIG> show some details of retrieval stages.

<FIG> and 7A-7C illustrate cross-sectionals views showing portions of the setting tool <NUM> and the liner hanger <NUM> in a first stages of setting. In these first stages, the liner hanger <NUM> is run to depth in the casing <NUM>. As shown in <FIG>, the balancing check valve assembly <NUM> is a check valve that allows for pressure to balance between the clean reserve volume <NUM> of the junk bonnet <NUM> and the clean tool volume <NUM> for the activation piston <NUM> on the setting tool <NUM>. Hydrostatic pressure builds as the setting tool <NUM> is run downhole, and the balancing check valve <NUM> allows fluid at the increasing pressure of the bonnet's volume <NUM> to enter into the tool's volume <NUM> for the activation piston <NUM>. This ensures that there is a balance of pressure once the activation piston <NUM> is ready to be moved.

As shown in <FIG>, the balancing check valve <NUM> has a piston chamber <NUM> and a piston <NUM>. The piston chamber <NUM>, in the form of a cylindrical chamber, is disposed in communication between the reserve and tool volumes <NUM>, <NUM> and has a chamber seat <NUM> disposed therein. The piston <NUM> is in the form of a cylindrical body disposed in the piston chamber <NUM>. The piston <NUM> is movable in the piston chamber <NUM> relative to the chamber seat <NUM> in response to a pressure differential. As shown, the movable piston <NUM> has an outer annular seal 107a that can selectively engage and seal with the chamber seat <NUM>. An inner annular seal 107b on the piston <NUM> stays sealed to the tool body <NUM> and can include chevron seals as shown.

The piston <NUM> in a closed position as shown in <FIG> has the seal 107a engaged with the chamber seat <NUM>, which prevents fluid communication in the reverse direction from the tool volume <NUM> to the reserve volume <NUM>. The piston <NUM> in an opened condition is disengaged from the chamber seat <NUM>, which permits fluid communication from the reserve volume <NUM> to the tool volume <NUM>. A biasing element <NUM> disposed in the piston chamber <NUM> biases the piston <NUM> toward the chamber seat <NUM> and acts against the pressure difference.

<FIG> illustrates another detailed view of the balancing check valve assembly <NUM> for the disclosed setting tool <NUM>. This view is similar to that disclosed above with reference to <FIG>. In this embodiment, the actuator <NUM> is shown with the locking mechanism <NUM>. Shown with the ball B engaged, the seat <NUM> is shifted downhole when the locking mechanism <NUM> is released. In contrast to the configuration in <FIG>, the piston <NUM> of the actuator <NUM> disposed in the bore <NUM> of the tool body <NUM> is not arranged to engage an uphole shear pin (88a; <FIG>) in an uphole direction for the secondary pressure relief system of the tool volume <NUM> discussed in more detail below.

As then shown in <FIG>, the setting tool <NUM> is then unlocked once run to depth. To do this, a ball B is landed on the setting tool's release seat 55a of the release mechanism <NUM>. Tubing pressure is increased to a predetermined pressure (e.g., <NUM> psi or <NUM>,<NUM> kPa) to shift a sleeve 55c, which unprops locking dogs 55d in the release mechanism <NUM>. Once shifted, the sleeve 55b is locked down, with a catch ring 55e, to prevent re-propping of the dogs 55d. With the release mechanism <NUM> unlocked, the setting tool's body <NUM> can be manipulated relative to other components of the system. Eventually with the applied pressure to a predetermined threshold, the ball B is expelled from expandable release seat 55a to travel toward the tool's second seat (<NUM>) for setting the liner hanger (<NUM>).

Continuing with the setting procedures, <FIG> shows details of the second stage of operation. As shown in <FIG>, the ball B lands on the second expandable seat <NUM> of the slick stinger actuator <NUM>. The seat <NUM> has pressure acting on both sides so the arrangement is pressure balanced and the shear pins <NUM> do not have a load on them until the ball B engages in the seat <NUM>. Pressure applied against the landed ball B shears the actuator seat <NUM> free of the locking mechanism <NUM> so that the actuator <NUM> can be operated. As noted previously, the locking mechanism <NUM> prevents premature actuation of the actuator <NUM>, which could be caused by any number of reasons during run-in. For example, the velocity of the fluid flow through the seat <NUM> could prematurely activate the actuator <NUM> if not locked in place.

The locking mechanism <NUM> includes a sleeve <NUM> having the actuator seat <NUM>. The sleeve <NUM> is held by shear pins <NUM> inside the tool body <NUM>, and a locking collet <NUM> has collet fingers <NUM> held engaged against a ring <NUM> inside the tool body <NUM>. As will be appreciated, other configurations can be used to lock the seat <NUM> in place.

While running in the hole with the liner hanger <NUM>/setting tool <NUM>, the actuator seat <NUM> is locked into place by the locking mechanism <NUM> having the supported locking collet <NUM>. The shear pins <NUM> prevent premature movement of the sleeve <NUM> in response to forces during run-in, such as any forces caused by fluid flow through the tool body <NUM>. Once ready to deploy the liner hanger <NUM> in the casing <NUM>, the actuator piston <NUM> may only be actuated after a closed pressure volume is pressurized to produce the required force to shear locking pins <NUM> and un-support the locking collet <NUM> so the seat <NUM> can engage (affix to) the piston <NUM>.

To do this, initial pressure is applied behind the dropped setting ball B landed on the expandable seat <NUM>, the sleeve <NUM> can shear the shear pin <NUM> once a predetermined force is reached. The sleeve <NUM> then shifts a short distance. The shifted sleeve <NUM> then shoulders against the actuator's piston <NUM> so that pressure applied against the seated ball B in the seat <NUM> can be applied to the actuator's piston <NUM>. A lock ring <NUM>, such as an expanding locking C-ring <NUM> on the sleeve <NUM>, can lock in a locking groove of the piston <NUM> to lock them together. This locking prevents re-supporting the collet <NUM> and locking the sleeve <NUM> again.

As shown in <FIG>, the back support on the collet fingers <NUM> is removed. The unsupported collet fingers <NUM> can allow shifting of the actuator piston <NUM> uphole (to the left in <FIG>) should the upper shear pin 88a be sheared according to procedures disclosed below.

As shown in <FIG>, the actuator piston <NUM> includes a temporary connection 88b with the tool bore <NUM>. The temporary connection 88b has a connected state configured to prevent movement of the actuator piston <NUM>. In response to a predetermined force, the temporary connection 88b has an unconnected state, which allow movement of the actuator piston <NUM> in response to the applied tubing pressure behind the deployed plug B engaged in the actuator seat <NUM>. As shown here, the temporary connection 88a can include shear pins disposed between the actuator piston <NUM> and the tool bore <NUM>.

During operation as shown in <FIG>, the setting tool <NUM> is activated to start shearing the hydraulic setting piston <NUM> of the liner hanger <NUM> free. Here, tubing pressure is increased behind the seated plug B to a predetermined pressure (e.g., <NUM> to <NUM> psi or <NUM>-<NUM>,<NUM> kPa) to start shearing the actuator piston <NUM> free. The actuator piston <NUM> may travel a short distance (d1) before being freed.

As shown in <FIG>, increased pressure can start to shear the hydraulic setting piston <NUM> free by shearing the shear pins 25a, and the setting piston <NUM> can move an initial distance (d2). As the actuator piston <NUM> moves, the distance of the upper shear pins 88a from a shoulder of the piston <NUM> increases. As noted previously, the setting volume <NUM> of the actuator <NUM> holds the clean actuation fluid communicated from the clean volume <NUM> by the balancing check valve <NUM>. This volume <NUM> is sealed from tubing fluids by the piston's seals 85a-b that engage inside the bore <NUM> of the setting tool's body <NUM>. Movement of the actuator piston <NUM> decreases this volume <NUM> and builds pressure that is communicated to the hanger's hydraulic setting piston <NUM>.

As then shown in <FIG>, tubing pressure is increased to an increased pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa) to shear the shear pins 88b of the actuator piston <NUM> and begin the transfer of fluid from the setting volume <NUM> to the hydraulic cylinder setting chamber <NUM> of the hanger's piston <NUM> to set the slips <NUM>. Fluid in the setting volume <NUM> communicates through ports <NUM>, <NUM> in the setting tool <NUM> and pack-off body <NUM> to reach a sealed annulus <NUM> between the pack-off body <NUM> and the inner bore <NUM> of the liner hanger's body <NUM>. Packing seals 99a-b and 107b-c on the setting tools <NUM> are sealed against the inner bore <NUM> so that the annulus <NUM> is clear of other fluids. The clean fluid can travel through the setting port <NUM> of the hanger <NUM> to the chamber <NUM> for the hanger's piston <NUM>.

Once the shear pins 88b are sheared, the volume <NUM> of the tool's volume <NUM> can be transferred to the liner hanger hydraulic chamber <NUM>. The tubing pressure is increased to a predetermined pressure until the liner hanger <NUM> takes liner hang weight. Preferably, the tubing pressure is increased in increments to the predetermined pressure. For example, the tubing pressure can be increased in <NUM> psi increments from <NUM>,<NUM> psi to reach <NUM>,<NUM> psi (<NUM>,<NUM> kPa increments from <NUM>,<NUM> kPa to reach <NUM>,<NUM> kPa).

As the actuator piston <NUM> travels a greater distance as shown in <FIG>, the hydraulic setting piston <NUM> moves a greater distance (d3) so that the slips <NUM> rid up the cones <NUM> and contact with the casing <NUM>. At the final tubing pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa), the pressure from the actuator piston <NUM> to the hydraulic setting chamber <NUM> is intensified to a greater pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa). During the time that the intensifier pressure increases, the pressure moves the hydraulic setting piston <NUM> to push the slips <NUM> onto the ramps of the cones <NUM>.

As can be seen, the actuator piston <NUM> transfers the clean fluid to the piston chamber <NUM>. The axial displacement of the closed ball seat <NUM> is equal to the axial displacement of the actuator piston <NUM>. The displaced volume created by the differential piston volume of the actuator piston <NUM> can sufficiently displace the hydraulic setting piston <NUM> to create slip contact with the casing <NUM>. The intensifying actuator piston <NUM> also compresses the fluid volume to create an elevated internal pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa). The working fluid may preferably be water because the Bulk Modulus of water can help calculate the required amount of water needed to pressurize the hydraulic setting piston <NUM> to deliver the pressure load to set the slips <NUM>.

Once the liner hanger <NUM> is determined to be able to take weight, the applied surface pressure is increased to the point where the setting ball B is expelled from the expandable seat <NUM> and the controlled closed volume is removed. The applied pressure from the surface drives the actuator piston <NUM> to apply pressure to the hydraulic chamber <NUM> of the hydraulic setting piston <NUM> as long as the setting ball B remains on the expandable seat <NUM> and the actuator piston <NUM> displaces to its fully stroked position.

As can be seen, the setting of the liner hanger <NUM> depends on applied pressure from the surface to a closed tubing volume created by the setting ball B on the expandable seat <NUM>. The setting ball B eventually expands the actuator seat <NUM> and is expelled at a predetermined pressure, such as <NUM>,<NUM> psi (<NUM>,<NUM> kPa) depending on the implementation.

As mentioned, debris-laden environment may increase the need for more force to move components to set the liner hanger <NUM>. For this reason, the actuator piston <NUM> provides a differential piston that takes the applied surface pressure and intensifies the output pressure at a configured ratio, such as <NUM>:<NUM>, to the hydraulic setting chamber <NUM> of the liner hanger <NUM>. As one example, input surface pressure of <NUM>,<NUM> psi (<NUM>,<NUM> kPa) can deliver an output pressure of <NUM>,<NUM> psi (<NUM>,<NUM> kPa) to the liner hanger system to force its way through bedded debris.

The total stroke of the actuator piston <NUM> accounts for the pressure to rupture the shear pins in the liner hanger's piston <NUM>, fully stroke the piston <NUM>, and drive the slips <NUM> into the wall of the casing <NUM> with the application of surface pressure with volume to spare. If another application of setting pressure is desired to be applied to the hydraulic setting piston <NUM> of the liner hanger <NUM>, operators can release the applied surface pressure, as this will allow the actuator piston <NUM> of the intensifier to return to its start position. The hydraulic setting piston <NUM> cannot go back to its original position due to a body lock ring or slip lock dogs. Yet, as the actuator piston <NUM> is pushed back by its compression spring <NUM>, a differential pressure is created that causes the balancing check valve <NUM> of the pack-off assembly <NUM> to accept clean fluid from the bonnet's volume <NUM>. This recharges the setting volume <NUM> with fluid for the next pressure application. At this point, the surface pressure may again be applied.

The slips <NUM> should be able to handle the liner hanger's weight. If the slips <NUM> are taking load, then pressuring-up of the tubing pressure can be performed until the ball B is expelled from the expandable set <NUM>. The expelling pressure can be a pressure of about <NUM>,<NUM> to <NUM>,<NUM> psi (<NUM>,<NUM>-<NUM>,<NUM> kPa) with a maximum of <NUM> psi (<NUM>,<NUM> kPa) intensified pressure to the hydraulic setting piston <NUM>. This pressure can be a safe burst load to the liner hanger <NUM>.

The expelling of the setting ball B through the expandable seat <NUM> in the debris environment may require applying surface pressures greater than the predetermined pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa) to the point where the intensified pressure of the actuator piston <NUM> delivers a pressure greater than a maximum pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa) that can potentially damage equipment.

<FIG> illustrate cross-sectionals views of another embodiment of the setting tool <NUM> and the liner hanger system in stages of setting. These views are similar to those disclosed above with reference to <FIG>. In this embodiment, the actuator <NUM> is shown with the locking mechanism <NUM>. Shown with the ball B engaged in <FIG>, the seat <NUM> is shifted downhole when the locking mechanism <NUM> is released, and pressure applied behind the seated ball B shifts the actuator piston <NUM>, reducing the tool volume <NUM>. In contrast to the configuration in <FIG>, the piston <NUM> of the actuator <NUM> disposed in the bore <NUM> of the tool body <NUM> is not arranged to engage a shear pin (88a; <FIG>) in an uphole direction for the secondary pressure relief system of the tool volume <NUM> discussed in more detail below.

The over-pressure venting assembly (i.e., venting valve <NUM>) can respond to the increase in the intensified pressure and can shift, but not shear a venting pin <NUM>. To prevent over-pressurization of the hydraulic setting piston <NUM> and its seals, for example, the venting valve <NUM> prevents any pressure above the maximum pressure (<NUM>,<NUM> psi or <NUM>,<NUM> kPa) from being delivered to the liner hanger <NUM>. As shown in <FIG> and described in more detail below, the venting valve <NUM> has a floating internal piston <NUM> and expands the tool volume <NUM> in reaction to the intensified pressure. For example, the gap between the floating piston <NUM> and the venting shear pins <NUM> can relieve hydrostatic pressure if the running tool <NUM> and the liner hanger assembly needs to be retrieved without setting. This relief of the hydrostatic pressure can prevent the slips <NUM> on the liner hanger from setting during retrieval.

In maintaining the pressure balance, the venting valve <NUM> can also respond to increases in temperature downhole by moving accordingly. For example, the gap between the floating piston <NUM> and the venting shear pins <NUM> can be calibrated for thermal expansion of the clean fluid in the volume <NUM> from ambient temperature up to about <NUM> F. This can help keep pressures balanced during run-in of the setting tool <NUM> and when operated at depth.

Once the maximum pressure (<NUM>,<NUM> psi or <NUM>,<NUM> kPa) threshold has been created, the floating piston <NUM> can shear a set of venting shear pins <NUM> to relieve the pressure to outside of the isolated volume <NUM> to the reserve volume <NUM>, where the floating junk bonnet <NUM> can react to the pressure increase through expanding volume upwards. At this point, the system equalizes and returns to its original position due to the compression spring <NUM>.

Once the setting ball B has been expelled, the system reverts to where the over-pressure venting valve <NUM> closes, the actuator piston <NUM> is pushed back into place by the compression spring <NUM>, the hydraulic setting piston <NUM> returns to an intermediate position determined by the location of the slip lock dogs, and any fluid draw into the volume <NUM> from the spring <NUM> pushing the actuator piston <NUM> comes from the balancing check valve <NUM>.

In a debris environment, the expelling pressure of the ball B from the seat <NUM> can be as much as <NUM>,<NUM> psi (<NUM>,<NUM> kPa) resulting in <NUM> kpsi (<NUM>,<NUM> kPa) in intensified pressure to the hydraulic setting piston <NUM> of the liner hanger <NUM>. This event would activate the over-pressure venting valve <NUM> to protect the liner hanger from over pressuring. Further details are disclosed below with reference to <FIG>.

In final stages of operation, cementation darts (not shown) are dropped, and a packer of the liner hanger system is set as normal. The running tool <NUM> can then be retrieved. As shown in <FIG>, the setting tool <NUM> includes a releasable connection <NUM> inside the hanger bore <NUM>. The releasable connection <NUM> in an engaged condition has locking dogs engaged with the hanger bore <NUM>. In the unengaged position, the releasable connection <NUM> has the locking dogs disengaged from the hanger bore <NUM>, which allows the stinger portion of the setting tool <NUM> to be removed from the hanger's bore <NUM>.

As shown in <FIG>, the setting tool <NUM> is pulled out of the liner hanger <NUM>, which has been set in the casing <NUM>. The packer actuator <NUM> is stroked a distance from the polished bore receptacle <NUM>. Meanwhile, at the other end, the pickup spacer <NUM> moves toward the setting tool's pack-off assembly <NUM> so that the locking dogs of the releasable connection <NUM> can be disengaged.

During setting operations, an alternative operation can be performed when the slips <NUM> fail to set due to debris when shearing the actuator piston <NUM>. As noted previously with reference to <FIG>, the tubing pressure is increased to the predetermined pressure (<NUM>,<NUM> psi or <NUM>,<NUM> kPa) to shear the shear pins 88b of the actuator piston <NUM> and to begin the transfer of fluid from the setting volume <NUM> to the hydraulic setting piston <NUM> to set the slips <NUM>. The actuator piston <NUM> moves a short distance d1 to stat shearing the actuator piston pins 88b.

Once the actuator piston <NUM> shears the pins 88b, the fluid volume of the tool chamber <NUM> is transferred to the hanger's hydraulic chamber <NUM>. Again, the transfer of input pressure to output pressure can be controlled by controlling the application of the tubing pressure, such as in stepped increments. The tubing pressure is increased to the predetermined pressure (<NUM>,<NUM> psi or <NUM>,<NUM> kPa), such as in <NUM> psi (<NUM>,<NUM> kPa) increments from <NUM>,<NUM> psi (<NUM>,<NUM> kPa), until the liner hanger <NUM> takes hang weight. The hydraulic setting piston <NUM> travels a distance d3 to achieve slip contact with the casing <NUM>.

At the increase (<NUM>,<NUM> psi or <NUM>,<NUM> kPa) tubing pressure, the intensifier pressure provided to the hydraulic setting piston <NUM> is intensified (e.g., to <NUM>,<NUM> psi or <NUM>,<NUM> kPa). The slips <NUM> should be able to handle the hang weight. The reasons for the slips <NUM> not taking a load may be because debris is preventing the hydraulic setting piston <NUM> from moving. If the slips <NUM> are not taking load and are not setting, then the tubing pressure may be relieved back to zero in this alternative operation. In relieving the pressure, the ball B is not expelled from the expandable seat <NUM>. The actuator piston <NUM> is reset by the compression spring <NUM> to refill the tool volume <NUM> with charging fluid from the balancing check valve <NUM>.

The refilling of the actuator piston's charging volume <NUM> allows for the full charging of the hydraulic chamber <NUM> of the liner hanger <NUM> to maximize the pressure delivered to setting the slips <NUM>. Once the actuator piston <NUM> returns to its initial position, tubing pressure may again be applied to the increased pressure (e.g., <NUM>,<NUM> to <NUM>,<NUM> psi in <NUM> psi increments or <NUM>,<NUM> to <NUM>,<NUM> kPa in <NUM>,<NUM> kPa increments). The travel of the actuator piston <NUM> will be much less than the initial movement where fluid transfer must occur to shift the hydraulic setting piston <NUM>. During the second pressure up to the increased tubing pressure <NUM>,<NUM>-<NUM>,<NUM> psi (<NUM>,<NUM> to <NUM>,<NUM> kPa), the intensified pressure delivered to the hydraulic setting piston <NUM> will immediately hit an elevated pressure (e.g., <NUM>,<NUM> psi or <NUM>,<NUM> kPa). This cycling of the setting volume <NUM> may happen as many times as needed to drive the slips into place.

Once the expelling pressure of <NUM>,<NUM> to <NUM>,<NUM> psi (<NUM>,<NUM> to <NUM>,<NUM> kPa) with a maximum of <NUM>,<NUM> psi (<NUM>,<NUM> kPa) intensified pressure to the hydraulic setting piston <NUM> is delivered, the setting ball B may be expelled from the seat <NUM>. Again, this pressure is expected to be a safe burst load to the liner hanger <NUM>.

Once the setting ball B has been expelled, the system reverts to where the over-pressure venting valve <NUM> closes, the actuator piston <NUM> is pushed back into place by the rectangular wire compression spring <NUM>, the hydraulic setting piston <NUM> returns to an intermediate position determined by the location of the slip lock dogs, and any fluid draw from the spring <NUM> pushing the sleeve <NUM> comes from the pressure balance check valve <NUM>. With this stage completed, operations can then follow other steps as normal.

When performing the setting stages, it is possible that too much pressure is applied by the setting tool <NUM> to the hydraulic setting piston <NUM> of the liner hanger <NUM>. The over-pressure venting assembly <NUM> of the tool <NUM> can prevent over-pressure. As shown in <FIG> and described previously, the over-pressure venting assembly having the venting valve <NUM> is disposed on the tool body <NUM> and is configured to relieve the intensified pressure of the actuation fluid above a predetermined threshold in the tool volume <NUM> to outside the tool body <NUM>.

The venting valve <NUM> includes a port 113a in the tool body <NUM> that is openable to communicate the tool volume <NUM> outside the tool body <NUM> to the reserve volume <NUM> contained by the bonnet <NUM>. The port 113a has a shearable pin <NUM>, and the venting valve <NUM> include a piston <NUM> disposed in fluid communication between the tool volume <NUM> and tubing pressure in the liner hanger (via an opening 113b). The piston <NUM> is movable to shear the shear pin <NUM> from the port 113a in response to the intensified pressure in the tool volume <NUM> exceeding the predetermined threshold. The piston <NUM> can move in a piston chamber <NUM> disposed in communication between the tool volume <NUM> and the port 113a. The piston <NUM> is movable in the piston chamber <NUM> relative to the shearable pin <NUM> in response to a pressure differential. The piston <NUM> in a first condition is disengaged with shearable pin <NUM> and prevents fluid communication from the tool volume <NUM> to the port 113a. As shown in <FIG>, the piston <NUM> in a second condition is engaged with the port's shearable pin 113a, and excess pressure in the tool volume <NUM> shears the shear pin <NUM>, permitting fluid communication from the tool volume <NUM> to the port 113a.

As shown, the piston <NUM> can include a cylindrical body disposed in the piston chamber <NUM>, and inner and outer annular seals 117a-b disposed on the cylindrical body of the piston <NUM> can seal with the piston chamber <NUM>. A biasing element <NUM> disposed in the piston chamber can bias the piston <NUM> against the pressure in the tool volume <NUM> so that the piston <NUM> is disengaged from the shar pin <NUM>. When retrieving the setting tool <NUM>, the piston <NUM> and the port 113a of the venting valve <NUM> can absorb changes in pressure. In necessary, a secondary venting system can be used in which the piston <NUM> can move further uphole to increase the tool volume <NUM>. This is described below with reference to <FIG>.

When performing the setting operations, it is also possible that the setting tool <NUM> needs to be retrieved without the liner hanger <NUM> having been set. As shown in <FIG>, the setting tool <NUM> and the liner hanger <NUM> are shown in yet another alternative operation. The slips <NUM> may have failed to set because enough pressure cannot be produced by the actuator piston <NUM>.

To pull the setting tool <NUM> and liner hanger <NUM>, an internal over-pressure mechanism can relieve the internal pressure of the tool volume <NUM> to prevent setting the slips <NUM>. As the system is pulled out of the borehole, the hydrostatic pressure decreases while the internal pressure of the tool volume <NUM> from the hydrostatic pressure at setting depth remains captured in the setting tool <NUM>.

To relieve that trapped pressure, the actuator piston <NUM> includes another temporary connection (e.g., shear pins) 88a with the tool bore <NUM>. The temporary connection 88a has a connected state configured to prevent an increase in the tool volume <NUM>. In response to a predetermined force, however, the temporary connection 88a has an unconnected state so the actuator piston <NUM> is able to move upward and so the tool volume <NUM> is allowed to increase.

As shown in <FIG>, the temporary connection 88a in the form of a retrieval venting shear pin 88a shears so the actuator piston <NUM> can move upward. This allow the trapped volume <NUM> to expand and relieves the trapped pressure, thus preventing the slips <NUM> from deploying while pulling the liner hanger <NUM> out of the hole.

In particular, the trapped pressure in the tool volume <NUM> acts against the shear pins 88a as the setting tool <NUM> and liner hanger <NUM> are retrieved. Eventually, the increased pressure shears these pins 88a to allow the tool volume <NUM> to increase. In turn, the increased tool volume <NUM> prevents the deployment of the slips <NUM> upon system retrieval by relieving the trapped hydrostatic pressure within the pack-off assembly <NUM> as the system is tripped back to the surface. The compensation is intended to prevent a threshold pressure (<NUM>,<NUM> psi or <NUM>,<NUM> kPa) from being delivered to the hydraulic setting piston <NUM> of the liner hanger <NUM>. As the external hydrostatic pressure is reduced when the system is brought to the surface, the trapped internal volume <NUM> and pressure in the tool <NUM> can be relieved via the floating piston <NUM> of the primary venting valve <NUM>. Because the floating piston <NUM> references external hydrostatic pressure, the piston <NUM> expands in response to the differential created from the trapped volume/pressure internally. This system is expected to dissipate/absorb <NUM>,<NUM> psi (<NUM>,<NUM> kPa).

The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. It will be appreciated with the benefit of the present disclosure that features described above in accordance with any embodiment or aspect of the disclosed subject matter can be utilized, either alone or in combination, with any other described feature, in any other embodiment or aspect of the disclosed subject matter.

Claim 1:
A setting tool (<NUM>) used on tubing (<NUM>) and activated by applied tubing pressure behind a deployed plug (B) to set a liner hanger (<NUM>) in a borehole (<NUM>), the liner hanger (<NUM>) having a hanger bore (<NUM>) with at least one inlet port (<NUM>), the at least one inlet port (<NUM>) disposed in fluid communication with a hydraulic setting mechanism (<NUM>) for the liner hanger, the setting tool (<NUM>) comprising:
a tool body (<NUM>) disposed on the tubing (<NUM>) and having a tool bore (<NUM>) for borehole fluid, a stinger portion of the tool body (<NUM>) being configured to seal inside the hanger bore (<NUM>) and having at least one outlet port (<NUM>, <NUM>), the at least one outlet port (<NUM>, <NUM>) being configured to be positioned in fluid communication with the at least one inlet port (<NUM>);
a bonnet (<NUM>) disposed on the tool body (<NUM>) and containing a first volume (<NUM>), the first volume (<NUM>) configured to hold an actuation fluid separate from the borehole fluid;
an actuator piston (<NUM>) disposed in the tool bore (<NUM>) and having a second volume (<NUM>) defined therewith, the second volume (<NUM>) configured to hold the actuation fluid, the at least one outlet port (<NUM>, <NUM>) communicating the second volume (<NUM>) with the at least one inlet port (<NUM>) of the hanger (<NUM>);
a check valve (<NUM>) disposed on the tool body (<NUM>) and being configured to communicate the actuation fluid from the first volume (<NUM>) to the second volume (<NUM>); and
an actuator seat (<NUM>) associated with the actuator piston (<NUM>) and configured to engage the deployed plug (B),
the actuator piston (<NUM>) being configured to move in response to the applied tubing pressure behind the deployed plug (B) engaged in the actuator seat (<NUM>), the actuator piston (<NUM>) in response to the movement being configured to intensify the applied tubing pressure on the actuation fluid in the second volume (<NUM>) to the hydraulic setting mechanism (<NUM>) for the liner hanger (<NUM>).