Convertible autofill float equipment having poppet valve and sliding sleeve

Abstract

A float assembly for a tubing string includes a sleeve, a poppet valve, and a shifting assembly. The sleeve can move from an open condition to a closed condition, controlling fluid flow through a bypass pathway via a bypass port in the sleeve. The valve (e.g., poppet valve) within the sleeve permits downbore fluid flow while preventing upbore fluid flow. Downstream, a shifting assembly in the sleeve allows upbore fluid flow when the shifting assembly is in a first condition. When in a second condition, the shifting assembly at least restricts downbore flow so the shifting assembly can shift the sleeve to close the bypass pathway once the fluid flow exceeds a first threshold. The shifting assembly can then be released to allow for unrestricted flow when a second threshold is exceeded.

Description

Atty. Dkt. No.: 230-0852WO (6827-PCT)-1- CONVERTIBLE AUTOFILL FLOAT EQUIPMENT HAVING POPPET VALVE AND SLIDING SLEEVECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Appl. 63 / 753,811 filed February 4, 2025, which is incorporated herein by reference in its entirety.BACKGROUND OF THE DISCLOSURE

[0002] After a wellbore is drilled in a formation, the wellbore can be lined with a tubular, such as a casing string or a liner. As the casing string is run into the wellbore, the casing string is typically filled with a fluid, such as drilling mud. As is common, a float assembly, such as a float shoe or a float collar, is placed at or near the bottom of the casing string. The float assembly has one or more unidirectional float valves that allow fluid flow to pass out from the casing string into the annulus but prevent fluid flow from the annulus back into the casing string.

[0003] While running the casing string into the wellbore, the wellbore fluid can be used to sustain a portion of the weight of the casing string by floating the casing string in the wellbore fluid. The float assembly prevents fluid flow into the bottom of the casing string, allowing the casing string to float in the fluid present in the wellbore. Once the casing string is in position in the wellbore, a cementing operation is performed to fill the annulus between the casing string and the wellbore with cement, which can prevent the casing string from moving within the wellbore once set. During the cementing operation, the one or more float valves allow flow of fluids, such as spacer fluid, cement, displacement fluid and the like, pumped down the casing string to pass through the unidirectional float valves and pass into the wellbore annulus. The float valves keep these fluids from flowing from the annulus back into the casing string. In the end, the combination of the cement and the casing string strengthens the wellbore and isolates certain areas of the formation behind the casing for the production of hydrocarbons.

[0004] For a typical example, Fig. 1 A illustrates a float collar 50A according to the prior art. The float collar 50A includes a tubular housing 52 accommodating a fill valve 60 therein. The fill valve 60 has a valve member that is generally mushroom shaped with a head biased upwardly against a valve seat by a spring circumjacent a stem of the valve member. A base in the seat supports the valve member and the spring.

[0005] The interior 54 of the housing 52 has an annulus filled with high density cement / concrete C therein. The cement C supports the fill valve 60, and the cement C has a passage communicating with the fill valve 60. During use, fluids including mud,Atty. Dkt. No.: 230-0852WO (6827-PCT)-2-conditioning fluid, and cement can flow through the passage and through the valve 60, but fluid from the wellbore is not permitted to pass uphole through the valve 60. The float collar 50A can be mounted with its box end 58 at the bottom of a casing string (not shown). The pin end 56 can attach to another extent of casing. Alternatively, a shoe (not shown) with box thread can thread to the pin end 56 of the float collar 50A to form a float shoe, or the float collar 50A may have a shoe integrally formed on the downhole end of the float collar 50A.

[0006] In some instances, a casing string may be deployed in a wellbore without floating the casing string. In this case, the unidirectional float valves are a hinderance to running in the casing string. Instead, a bidirectional valve is needed, allowing fluid flow to pass up into the casing string. During run in, for example, a convertible valve acts as a bidirectional valve, and the convertible valve is then converted to a unidirectional valve, operating like a typical float valve, once positioned downhole.

[0007] As can be seen, the conversion of the convertible valve allows fluid flow upwards during run in but prevents flow back into the casing string during later pumping operations. Convertible valves, or auto-fill valves, are known in the industry. A convertible valve of the prior art typically relies on a flapper valve, which is maintained in an open position during run in to allow automatic filling of the casing string. The convertible valve is then converted to a unidirectional valve by releasing the flapper from the open position so the flapper can then be biased towards the closed position.

[0008] For example, Fig. 1B shows a float collar 50B as disclosed in US 10,208,567 having a convertible valve arrangement of the prior art. The float collar 50B has a tubular housing 52 attached to a tubular string 15. A valve assembly positioned within the tubular housing 52 includes flapper seats 62, flapper valves 64, a tubular element 70, and ball plug 76. The flapper seats 62 are attached to the interior of the tubular housing 52, and the flapper valves 64 are hingedly attached to the flapper seats 62 and are movable between opened and closed positions. The tubular element 70 is releasably connected by a shear pin 71 or one of the flapper seats 62. The tubular element 70 holds the flapper valves 64 in the opened position. The tubular element 70 has a downstream seat 72 and an upstream seat 74, which keep the ball plug 76 in the tubular element 70. The ball plug 76 is movable between the upstream and downstream seats 72, 74.

[0009] US 12,012,812 discloses another example of float equipment having a convertible valve assembly of the prior art. A flow-actuated valve includes a body, a poppet, a spring, and a shifter. The poppet is movable relative to the body between an open position and a closed position, and the spring biases the poppet toward the closedAtty. Dkt. No.: 230-0852WO (6827-PCT)-3-position. The shifter has a drogue and a detent engaged with a detent profile of the poppet and a locking receptacle of the body when in an auto-fill mode, thereby keeping the poppet in a partially open position. The valve is operable to shift to a float mode in response to a first flow rate moving the poppet toward the open position to disengage the detent from the locking receptacle and a second flow rate imparting a drag force on the drogue sufficient to disengage the detent from the detent profile. The second flow rate is different than the first flow rate.

[0010] US 2024 / 0410251 discloses yet another example of float equipment having a convertible valve assembly of the prior art. A convertible valve assembly includes a valve housing defining a throughbore and includes a valve assembly for controlling fluid flow through the throughbore. The valve assembly has an upper plunger valve with an upper valve element and has a lower plunger valve with a lower valve element. The upper valve element and the lower valve element are connected such that the valve elements move in unison. The valve assembly has an open position such that both the upper and lower valve elements allow fluid flow through the valve assembly. The valve assembly has a closed position such that both the upper and lower valve elements are positioned to prevent fluid flow through the valve assembly. A retainer assembly for maintaining the valve assembly in the open position can selectively release the valve assembly to the closed position such that the upper and lower valves are biased toward the closed position.

[0011] Although existing float equipment may be useful, operators may require different configurations to improve functioning downhole. Accordingly, 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 above.SUMMARY OF THE DISCLOSURE

[0012] According to the present disclosure, a float assembly is for use on a tubing string having a throughbore for fluid flow. The float assembly comprises a housing, a sleeve, at least one valve, and a shifting assembly. (The at least one valve can be a poppet valve or other type of one-way valve, check valve, etc.) The housing is configured to couple to the tubing string. The housing defines a bore therein communicating with the throughbore of the tubing string. The sleeve is disposed in the bore and is movable from an open condition to a closed condition. The sleeve defines a flow passage and defines a bypass port. With the sleeve in the open condition, the bypass port is disposed in communication with a bypass pathway. With the sleeve in the closed condition, the bypass port is disposed out of communication with the bypass pathway.Atty. Dkt. No.: 230-0852WO (6827-PCT)-4-

[0013] The at least one valve is disposed in the flow passage of the sleeve. The at least one valve permits fluid flow in a downbore direction and prevents fluid flow in an upbore direction. The shifting assembly is disposed in the flow passage of the sleeve and is convertible between a first condition and a second condition. The shifting assembly in the first condition permits fluid flow in at least the upbore direction. Meanwhile, the shifting assembly in the second condition is configured to move the sleeve from the opened condition to the closed condition in response to fluid flow in the downbore direction above a first predetermined level.

[0014] In one configuration, the shifting assembly can comprise a flow tube and a plug. The flow tube has an upbore barrier and has a downbore barrier. The plug is movable in the flow tube between the upbore barrier and the downbore barrier. The shifting assembly in the first condition has the plug engaged with the upbore barrier and permits fluid flow in the upbore direction. The shifting assembly in the second condition has the plug engaged with the downbore barrier and at least restricts fluid flow in the downbore direction.

[0015] In one example, the shifting assembly can be disposed downbore of the at least one valve. The flow tube can comprise a releasable connection to the sleeve. The releasable connection can be releasable in response to fluid flow in the downbore direction above a second predetermined level acting against the plug engaged in the downbore barrier of the flow tube.

[0016] In another example, the shifting assembly can be disposed downbore of the at least one valve. The downbore barrier can comprise a releasable connection to the flow tube. The releasable connection can be releasable in response to fluid flow in the downbore direction above a second predetermined level acting against the plug engaged in the downbore barrier.

[0017] In one configuration, the bore of the housing can define an annular space for the bypass pathway about the sleeve. The bypass port can be defined in the sleeve between the at least one valve and the shifting assembly. The bypass port on the sleeve in the open condition can be aligned with the annular space and can be disposed in communication with the bypass pathway. Meanwhile, the bypass port on the sleeve in the closed condition can be misaligned with the annular space and can be disposed out of communication with the bypass pathway.

[0018] In an alternative configuration, the housing can define an external port for the bypass pathway communicating the bore outside the housing. The bypass port defined in the sleeve can be defined upbore of the at least one valve. The bypass port with the sleeve in the opened condition can be aligned with the external port and can be disposedAtty. Dkt. No.: 230-0852WO (6827-PCT)-5-in communication with the bypass pathway. Meanwhile, the bypass port on the sleeve in the closed condition can be misaligned with the external port and can be disposed out of communication with the bypass pathway.

[0019] According to the present disclosure, a method is used for a tubing string in a wellbore, the tubing string having a throughbore for fluid flow. The method comprises: deploying the tubing string in the wellbore while allowing fluid flow in an upbore direction and a downbore direction through a bypass pathway of a float assembly in an opened state, the float assembly disposed on the tubing string and having a sleeve, at least one valve (such as a poppet valve or other type of one-way valve or check valve), and a shifting assembly, the sleeve disposed in the float assembly, the at least one valve disposed in the sleeve, the shifting assembly disposed in the sleeve and disposed downbore of the at least one valve; converting the bypass pathway of the float assembly from the opened state to a closed state; and permitting fluid flow only in the downbore direction through the at least one valve with the bypass pathway of float assembly in the closed condition.

[0020] The step of converting the bypass pathway of the float assembly from the opened state to a closed state can comprise: pumping fluid flow in the downbore direction; restricting fluid flow pumped in the downbore direction through the shifting assembly; moving the sleeve in the float assembly from an opened condition to a closed condition relative to the bypass pathway of the float assembly in response to fluid flow pumped in the downbore direction to a first predetermined level; and closing off fluid communication of a bypass port in the sleeve with the bypass pathway in response to the sleeve moved to the closed condition.

[0021] The foregoing summary is not intended to summarize each potential configuration or every aspect of the present disclosure.BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1A illustrates a float collar according to the prior art.

[0023] Fig. 1 B illustrates another float assembly having a convertible valve assembly according to the prior art.

[0024] Fig. 2A illustrates a liner system having a liner disposed in a borehole and having one or more autofill float assemblies according to the present disclosure.

[0025] Fig. 2B illustrates an isolated view of an autofill float assembly according to the present disclosure.

[0026] Fig. 3A illustrates an autofill float assembly having poppet valves and an internal bypass of the present disclosure in a run-in condition.Atty. Dkt. No.: 230-0852WO (6827-PCT)-6-

[0027] Fig. 3B illustrates the autofill float assembly of Fig. 3A in a converted condition.

[0028] Fig. 3C illustrates the autofill float assembly of Fig. 3A in a final condition.

[0029] Fig. 3D illustrates the autofill float assembly of Fig. 3A with an alternative arrangement for the final condition.

[0030] Fig. 4A illustrates an autofill float assembly having poppet valves and an external bypass in a run-in condition.

[0031] Fig. 4B illustrates the autofill float assembly of Fig. 4A in a converted condition.

[0032] Fig. 4C illustrates the autofill float assembly of Fig. 4A in a final condition.

[0033] Fig. 4D illustrates the autofill float assembly of Fig. 4A with an alternative arrangement for the final condition.

[0034] Fig. 5A illustrates an autofill float assembly similar to that in Fig. 3A, but having a shifting assembly disposed upbore of the poppet valves.

[0035] Fig. 5B illustrates another autofill float assembly similar to that in Fig. 4A, but having a shifting assembly disposed upbore of the poppet valves.DETAILED DESCRIPTION OF THE DISCLOSURE

[0036] Fig. 2A illustrates a liner system 20 being lowered into a wellbore 10 on a work string 24. The wellbore 10 may have a cased portion 12 and an open hole portion 14 and may or may not have a horizontal section. A liner hanger 26 is supported by the work string 24 and is operable to secure a tubing string 22 (e.g., casing string or liner) in the wellbore 10. The work string 24 and the liner hanger 26 may include and / or be operable with any conventional running tools known in the art for securing liner hangers in wells.

[0037] The liner 22 can have one or more float assemblies 30, 32 having an autofill configuration and allowing fluids to enter and exit the liner 22 while the liner 22 is deployed into the wellbore 10. During run-in of the liner 22, for example, the wellbore 10 can be damaged by surge pressure arising from displaced wellbore fluid exerting pressure on the wellbore 10. To help alleviate surge pressure, the one or more float assemblies 30, 32 are designed to permit wellbore fluids to flow into the liner 22 while the liner 22 is lowered into the wellbore 10. As a result, wellbore fluids can be displaced into the liner 22 as it is lowered, which reduces surge pressure. In this way, the one or more float assemblies 30, 32 can allow the liner 22 to be run into the wellbore 10 at a more efficient speed without damaging the wellbore 10.

[0038] Although the one or more float assemblies 30, 32 are designed for bi-directional operation to permit wellbore fluids to flow into the liner 22 during run-in, the one or more float assemblies 30, 32 are also convertible to uni-directional operation to permit only oneway flow of fluid to flow out of the liner 22 for the cementing operation. During thisAtty. Dkt. No.: 230-0852WO (6827-PCT)-7-cementing operation, for example, displacement fluid, spacers fluid, cement slurry, and the like is pumped downhole through the liner 22 and into the annular area between the liner 22 and the wellbore 10. During this operation, the one or more float assemblies 30, 32 act as a one-way check valve permitting cement slurry to be expelled from the liner 22 while subsequently preventing the cement slurry from reverse flowing (also referred to as a U-tubing) back into the liner 22.

[0039] Without the uni-directional operation at the downhole end of the liner 22, the cement slurry may reverse flow into the liner 22 if the hydrostatic pressure within the wellbore annulus exceeds the hydrostatic pressure within the liner 22. For example, after the cement slurry is expelled from the liner 22, hydrostatic pressure within the liner 22 is sometimes relieved or reduced. Hydrostatic pressure within the wellbore annulus may then exceed the hydrostatic pressure within the liner 22. In this situation, the one or more float assemblies 30, 32 must act as a one-way check-valve to prevent reverse flow.

[0040] For the one or more float valve assemblies 30, 32 to permit wellbore fluids to flow into the liner 22 during run-in, the one or more float assemblies 30, 32 include a convertible valve assembly, as disclosed below. Such a convertible valve assembly initially permits wellbore fluid to enter into the liner 22 during run-in to alleviate surge pressure within the wellbore. The convertible valve assembly is then converted to a oneway check valve to prevent cement slurry from reverse flowing from the annular area back into the liner 22.

[0041] In one configuration, for example, one float assembly 30 can be part of a float shoe on the liner system 20. During run-in, the float assembly 30 can have an autofill configuration, allowing fluids to enter and exit the liner 22 while the liner 22 is lowered into the wellbore 10 to alleviate surge pressure within the wellbore 10. During cementation, the float assembly 30 can then be converted to operate as a one-way valve to prevent cement from reverse flowing back into the liner 22 after placement.

[0042] In such a configuration, another float valve assembly 32 can also be used and can be part of a float collar on the liner system 20. As part of a float collar, the float assembly 32 may be placed one or more joints above a guide shoe or a float shoe. This other float assembly 32 can also have an autofill configuration, allowing fluids to enter and exit the liner 22 while the liner 22 is lowered into the wellbore 10 to alleviate surge pressure within the wellbore 10. Then, for cementing, the other float valve assembly 32 can be converted to a one-way valve to prevent reverse flow into the liner 22.

[0043] Additionally, this other float assembly 32 can provide a seat for cement plugs during a cement operation. The space 34 between the float assemblies (i.e., float shoe 30Atty. Dkt. No.: 230-0852WO (6827-PCT)-8-and the float collar 32) can be used to entrap the contaminated fluids left from the wiping action of a top cementing plug during the cement operation. This space 34 can keep the contaminated fluid away from the float shoe 30 where a strong cement bond is needed.

[0044] In another arrangement, the space 34 between the float valve assemblies 32, 36 can initially be filled with a material having a density less than the density of the fluids in the wellbore 10. For example, the space 34 may hold air, nitrogen, light weight liquids or solids, foam, polystyrene, plastic, rubber, or combinations thereof. For run-in, the space 34 of lower density can make the liner 22 buoyant as the liner 22 is moved through the fluids in the wellbore 10, which can reduce drag forces created by contact with the surfaces of the wellbore 10. The float assemblies 30, 32 can be initially configured for autofill to allow fluid communication into and out of the liner 22 should surge pressure within the wellbore 10 needs to be alleviated while the liner 22 is lowered into the wellbore 10. Then, to perform cementing, the float assemblies 30, 32 can be converted to a oneway valve to contain backpressure and prevent cement from flowing back into the liner 22 after placement.

[0045] As noted above, one or more of the float assemblies 30, 32 can have an autofill configuration. Briefly, Fig. 2B illustrates an isolated view of an example of an autofill float assembly 30 according to the present disclosure. The float assembly 30 includes a housing 101, a sleeve 110, at least one valve 130, and a shifting assembly 160. The housing 101 couples to the tubing string (22), and the housing 101 defines a bore 102 therein communicating with the throughbore of the tubing string (22). The sleeve 110 is disposed in the housing’s bore 102 and is movable from an opened condition to a closed condition. The sleeve 110 defines a flow passage 122, such as in filling material 120. The sleeve 110 also defines a bypass port 114. When the sleeve 110 is in the opened condition, the bypass port 114 is disposed in communication with a bypass pathway 108. When the sleeve (110) is in the closed condition, the bypass port 114 is disposed out of communication with the bypass pathway (108).

[0046] The at least one valve 130 is disposed in the flow passage 122 of the sleeve 110. The at least one valve 130 can be a one-way valve, a check valve, a spring biased poppet valve, a flapper valve, a ball check valve, or the like. Two valves 130 are shown here and can operate independently. The at least one valve 130 permits fluid flow in a downbore direction and prevents fluid flow in an upbore direction.

[0047] The shifting assembly 160 is disposed in the flow passage 122 of the sleeve 110. The shifting assembly 160 is convertible between a first condition and a second condition. The shifting assembly 160 in the first condition permits fluid flow in at least the upboreAtty. Dkt. No.: 230-0852WO (6827-PCT)-9-direction, whereas the shifting assembly 160 in the second condition is configured to move the sleeve 110 from the opened condition to the closed condition in response to fluid flow in the downbore direction above a first predetermined level.

[0048] Figs. 3A-3D illustrate cross-sections of an autofill float assembly 100 according to the present disclosure, which can be used on a liner as discussed above or can be used on another type of tubing string. The autofill float assembly 100 solves issues associated with float equipment when used to alleviate surge pressure during deployment (run-in) of a tubular string. As shown, the autofill float assembly 100 uses poppet valves 130, which are maintained independent of one another. (Although dual valves 130 being maintained independent of one another are shown and described herein, the autofill float assembly 100 can use one or more valves 130. Moreover, although the use of a spring-loaded poppet valve 130 is shown and described, other types of one-way valve, check valve, flapper valve, ball check valve, and the like can be used.)

[0049] During run-in, a selective bypass pathway 108 in an opened state allows for reverse flow to bypass the poppet valves 130. A shifting assembly 160 of the autofill float assembly 100 is activated by an increased flow rate, which converts the selective bypass pathway 108 from an opened state to a closed state. As a result, the autofill float assembly 100 is converted from bi-directional operation (suitable for surge pressure alleviation) to downbore-only operation (suitable for cementing).

[0050] As shown in Fig. 3A, the autofill float assembly 100 includes a housing or body 101 , a sleeve 110, and a poppet valve 130. Two poppet valves 130 are shown, but other configurations of the autofill float assembly 100 may have one poppet valve 130 or more than two poppet valves 130 of the present disclosure. The housing 101 is configured to couple to the tubing string (not shown), and the housing 101 defines a bore 102 therein communicating with the throughbore of the tubing. As will be appreciated, the housing 101 can be a tubular having appropriate box and / or pins on the ends for coupling to tubulars or other downhole tools on a tubing string.

[0051] The sleeve 110 is disposed in the housing’s bore 102. In a run-in condition shown in Fig. 3A, the sleeve 110 is spaced from a shoulder 105 in the housing’s bore 102. A releasable connection 106 holds the sleeve 110 in the run-in condition. This releasable connection 106, as well as others disclosed herein, can be a shear pin, a shear ring, a shear screw, a breakaway bolt, a frangible stud, a spring clip, a ball dent, a releasable latch, or another feature known in the art. At the upbore end, the sleeve 110 includes spacers 115, which are engaged in the housing’s bore 102 and allow for fluid flow to pass in the annular space between the sleeve 110 and the housing’s bore 102.Atty. Dkt. No.: 230-0852WO (6827-PCT)-10-

[0052] Each of the poppet valves 130 includes a support 140 and a poppet 150. As shown, the sleeve 110 can have a filler material 120, such as cement or the like, disposed in the bore 112 of the sleeve 110. The filler material 120 defines a flow passage 122 communicating with the housing’s bore 102, and the filler material 120 supports the poppet valves 130.

[0053] For its part, the support 140 as shown in Fig. 3A has an insert 141 defining a chamber 143, which has a seat 145 communicating with the flow passage 122. A base or support ledge 142 disposed in the chamber 143 has the poppet 150 disposed thereon. The poppet 150 is biased by a biasing element 158 toward the seat 145. As further shown, the poppet 150 includes a head 152, a seal 153, and a stem 154, and a biasing element 158. The poppet 150 is biased by the biasing element 158 toward the seat 145. For example, the biasing element 158 can be a spring engaged between the support ledge 142 and the poppet’s head 152.

[0054] The poppet 150 is movably disposed on the support ledge 142 and is biased by the spring 158 from an opened position (in which the head 152 is distanced from the seat 145) to a closed position (in which the head 152 is engaged against the seat 145). The poppet 150 in the opened position permits fluid flow through the flow passage 122 (as well as bore 112 and chamber 143) in downbore and upbore directions. The poppet 150 in the closed position permits fluid flow through the flow passage 122 (as well as bore 112 and chamber 143) in the downbore direction and restricts fluid flow in the upbore direction.

[0055] Downbore of the poppet valves 130, the sleeve 110 defines flow openings or bypass ports 114, which allow for fluid communication between the housing’s bore 102 and the sleeve’s bore 112. The shifting assembly 160 includes a flow tube or cage 162, an upbore barrier 164, a downbore barrier 166, and an occluding device 170 (e.g., a plug or a ball). The upbore barrier 164 is supported in the filler material 120 in the sleeve 110. The flow tube 162 extends from the upbore barrier 164 and is attached by fixtures 168a. The downbore barrier 166 is attached to the distal end of the flow tube 162, and the plug 170 is movable inside the flow tube 162 between the upbore barrier 164 and the downbore barrier 166.

[0056] As shown, the flow tube 162 can define one or more port holes 165, which can allow fluid to be circulated at a circulation rate downbore through the autofill float assembly 100 even after the plug 170 forms a fluid tight seal with the downbore barrier 166. The one or more port holes 165 can provide for a low circulation rate so the autofill float assembly 100 can remain unconverted until a predefined pressure from downbore fluid flow is pumped against the plug 170 in the downbore barrier 166 to shift the sleeve 110 asAtty. Dkt. No.: 230-0852WO (6827-PCT)-11-described below. Flow through such port holes 165 can be useful for flowing debris (such as cuttings, lost circulation material, high solids content mud, or formation rock from a weak formation) out of the casing string, for example.

[0057] For example, the one or more port holes 165 allow downward fluid flow up to a preselected flow rate without building sufficient pressure above the plug 170 to cause the release of the sleeve’s releasable connection 106. Flow through the one or more port holes 165 exits the flow tube 162 into the downhole portion of the float assembly 100. In one configuration, the one or more port holes 165 can be designed to allow a relatively low flow rate of around 2 to 5 barrels per minute (bpm) without actuating the sleeve’s releasable connection 106. (In general, the flow rate can range between 2 to 12 bmp, such as 2 to 4, 5 to 8, or 10 to 12 bpm.) When the pump rate is increased to a preselected rate, such as 5 to 8 barrels per minute (bpm), pressure in the flow tube 162 above the plug 170 rises to a preselected pressure, at which point the plug 170, pushing downward on the downbore barrier 166, shears the sleeve’s releasable connection 106, thereby releasing the sleeve 110 to shift in the housing 101. These flow rates are merely presented as an example, and other arrangements can be configured to meet the needs of particular implementations. A person of ordinary skill in the art will appreciate that the required flow rates, pressures, and forces can be adjusted by altering the size / number of the port holes 165 and the strength of the releasable connection 106.

[0058] The upbore barrier 164 defines a flow opening, and the plug 170 can engage the upbore barrier 164 in response to upbore fluid flow. The upbore barrier 164 can be a seat, a crossbar, or the like and can include flutes, protrusions, gaps, or the like that allow for fluid to pass through the upbore barrier 164 even when the plug 170 is engaged. As already noted, the plug 170 may be any type of occluding device, including, but not limited to, a ball or another flow-obstructing device.

[0059] The downbore barrier 166 defines a flow opening, and the plug 170 can engage the downbore barrier 166 in response to downbore fluid flow. The downbore barrier 166 can be a seat, such as a ball seat, which prevents fluid from passing in the downstream direction when the plug 170 is engaged.

[0060] During run-in as shown in Fig. 3A, upbore flow can communicate along the selective bypass pathway 108. The plug 170 can engage in the upbore barrier 164 in response to reverse flow upbore through the autofill float assembly 100. In the run-in (autofill) condition shown in Fig. 3A, flow can pass in an upbore direction through downbore barrier 166, the flow tube 162, and the plug 170 engaged in the upbore barrier 164. Moreover, in the selective bypass pathway 108, the upbore flow can pass out of theAtty. Dkt. No.: 230-0852WO (6827-PCT)-12-bypass ports 114 to the annular area (of the selective bypass pathway 108) between the sleeve 110 and the housing’s bore 102. The upbore flow can now pass further uphole past the spacers 115 on the end of the sleeve 110.

[0061] When this autofill feature is no longer required, operators increase the flow rate from surface. The increased flow can flow downbore through the annular area (of the selective bypass pathway 108) and the bypass ports 114. If sufficient, the increased flow can also open the poppet valves 130, which allow the downbore flow to pass. The increased downbore flow in turn acts on the plug 170, eventually lodging the plug 170 against the downbore barrier 166 on the shifting assembly 160.

[0062] At this point, the increased downbore flow acts on the sleeve 110. Once a sufficient force is reached, the releasable connection 106 shears the sleeve 110 free to move in the housing’s bore 102. As shown in Fig. 3B, the autofill float assembly 100 then converts to a converted condition. The sleeve 110 shifts in the housing’s bore 102 from an opened condition to a closed condition. The sleeve 110 engages a shoulder 105, which prevents further downbore shifting of the sleeve 110. Although not shown, a lock (e.g., latch ring, ratcheting lock ring, detent ring, locking taper, groove arrangement, or the like) may lock the sleeve 110 in its downbore position so it cannot move upbore after shifting. With the sleeve 110 engaging the shoulder 105, the bypass ports 114 in the sleeve 110 move from the expanded portion of the bore 112. As shown in Fig. 3B, the ports 114 are now sealed from the annular area (of the selective bypass pathway 108) by the seals 103 on the sleeve 110 engaged in the housing’s bore 102.

[0063] In the end, the shifting assembly 160 can be retained, connected to the sleeve 110. Alternatively, the shifting assembly 160 can be dropped, in whole or part, from the end of the tubing string into the wellbore (or, if present, shoe assembly) depending on the use and position of any releasable connections for the shifting assembly 160. For example, the increased downbore flow can continue acting on the plug 170 engaged in the downbore barrier 166, and at least the plug 170 can eventually be released from the shifting assembly 160, which would allow for fluid flow in both the upbore and downbore directions through the shifting assembly 160. The downbore barrier 166 can be a releasable ball seat that can release the plug 170 in response to a predetermined force.

[0064] Alternatively, as shown in Fig. 3C, a releasable connection 168b can release the plug 170 and the downbore barrier 166 free from the flow tube 162 when a sufficient force is reached. This releasable connection 168b, as well as others disclosed herein, can be a shear pin, a shear screw, a frangible stud, a spring clip, a ball dent, a releasable latch, or another feature. Now, the autofill float assembly 100 can operate in a uni-directionalAtty. Dkt. No.: 230-0852WO (6827-PCT)-13- (downbore-only) flow state in which fluid can be channeled through the poppet valves 130 in a downbore-only direction.

[0065] After the hydrostatic pressure within the tubular string reaches a predetermined level or threshold, for example, the plug 170 exerts enough force against the downbore barrier 166 to shear the releasable connection 168b connecting the downbore barrier 166 to the flow tube 162, thereby releasing the downbore barrier 166 from the flow tube 162 as shown in Fig. 3C. After the downbore barrier 166 is released, the downbore barrier 166 is pushed downbore within the wellbore by fluid being pumped through the tubular string such that the downbore barrier 166 is ejected from the housing 101. The ejection of the downbore barrier 166 permits unobstructed flow through the poppet valves 130, which reduces circulating pressures on surface. As noted, the poppet valves 130 is normally closed and opens in response to a downbore pressure differential sufficient to shift the poppets 150 against the springs 158. Cement slurry can be expelled from the tubular string into the surrounding wellbore (10). After the cement slurry is expelled, the poppet valves 130, which are biased to the closed position by the biasing springs 158, prevent reverse flow of the cement slurry so the float assembly acts as a one-way check valve preventing reverse flow or U-tubing of the cement slurry.

[0066] As an alternative shown in Fig. 3D, the fixture 168a on the upbore end of the flow tube 162 can be a releasable connection, which released the flow tube 162 free when a sufficient force is reached. This releasable connection 168a, as well as others disclosed herein, can be a shear pin, a shear screw, a frangible stud, a spring clip, a ball dent, a releasable latch, or another feature. With the flow tube 162 released, the autofill float assembly 100 can operate in a downbore-only flow state in which fluid can be channeled through the poppet valves 130 in a downbore-only direction.

[0067] As noted above, subject flow rates can range between 2 to 12 bpm, such as in the intervals of 2 to 4, 5 to 8, or 10 to 12 bpm. An example flow rate to shear the releasable connection 106 and shift the sleeve 110 can be in the range of approximately 5 to 8 bpm. An example flow rate to shear the releasable connection 168a or 168b and release the flow tube 162 or the downbore barrier 166 can be in the range of approximately greater than the 5 to 8 bpm used to free the sleeve 110. These flow rates are merely presented as an example, and other arrangements can be configured to meet the needs of particular implementations. A person of ordinary skill in the art will appreciate that the required flow rates, pressures, and forces can be adjusted by altering the strengths of the releasable connections 106, 168a-b.Atty. Dkt. No.: 230-0852WO (6827-PCT)-14-

[0068] Figs. 4A-4D illustrates cross-sections of another autofill float assembly 100 according to the present disclosure. This autofill float assembly 100 is similar to that discussed previously so the same reference numerals are used for equivalent components. The autofill float assembly 100 solves issues associated with float equipment when used to alleviate surge pressure during deployment (run-in) of a tubular string. The autofill float assembly 100 uses poppet valves 130, which are maintained independently. (Although dual valves 130 being maintained independent of one another are shown and described herein, the autofill float assembly 100 can use one or more valves 130. Moreover, although the use of a spring-loaded poppet valve 130 is shown and described, other types of one-way valve, check valve, flapper valve, ball check valve, and the like can be used.)

[0069] During run-in, a selective bypass pathway 108 allows for reverse flow to bypass the poppet valves 130. The shifting assembly 160 is activated by an increased flow rate, which converts the selective bypass pathway 108 from an opened state to a closed state. As a result, the autofill float assembly 100 is converted from bi-directional operation to downbore-only operation.

[0070] As shown in Fig. 4A, the autofill float assembly 100 includes a housing or body 101, a sleeve 110, and a poppet valve 130. Two poppet valves 130 are shown, but other configurations of the autofill float assembly 100 may have one poppet valve 130 or more than two poppet valves 130 of the present disclosure. The housing 101 is configured to couple to the tubing string (not shown), and the housing 101 defines a bore 102 therein communicating with the throughbore of the tubing. As will be appreciated, the housing 101 can be a tubular having appropriate box and / or pins on the ends for coupling to tubing or other downhole tools on the tubing string.

[0071] The sleeve 110 is disposed in the housing’s bore 102. In a run-in condition shown in Fig. 4A, the sleeve 110 is spaced from a shoulder 105 in the housing’s bore 102. A releasable connection 106, such as shear pins, shear screws, or other feature, holds the sleeve 110 in the run-in condition.

[0072] Each of the poppet valves 130 includes a support 140 and a poppet 150. As shown, the sleeve 110 can have a filler material 120, such as cement or the like, disposed in the bore 112 of the sleeve 110. The filler material 120 defines a flow passage 122 communicating with the housing’s bore 102, and the filler material 120 supports the poppet valves 130.

[0073] For its part, the support 140 as shown in Fig. 4A has an insert 141 defining a chamber 143, which has a seat 145 communicating with the flow passage 122. A base orAtty. Dkt. No.: 230-0852WO (6827-PCT)-15-support ledge 142 disposed in the chamber 143 has the poppet 150 disposed thereon. The poppet 150 is biased by a biasing element 158 toward the seat 145. As further shown, the poppet 150 includes a head 152, a seal 153, and a stem 154, and a biasing element 158. The poppet 150 is biased by the biasing element 158 toward the seat 145. For example, the biasing element 158 can be a spring engaged between the support ledge 142 and the poppet’s head 152.

[0074] The poppet 150 is movably disposed on the support ledge 142 and is biased by the spring 158 from an opened position (in which the head 152 is distanced from the seat 145) to a closed position (in which the head 152 is engaged against the seat 145). The poppet 150 in the opened position permits fluid flow through the flow passage 122 (as well as bore 112 and chamber 143) in downbore and upbore directions. The poppet 150 in the closed position permits fluid flow through the flow passage 122 (as well as bore 112 and chamber 143) in the downbore direction and restricts fluid flow in the upbore direction.

[0075] Upbore of the poppet valves 130, the sleeve 110 defines flow openings or bypass ports 114. To allow for fluid communication to alleviate surge pressure, these bypass ports 114 are aligned with external ports 104 on the housing 101. The shifting assembly 160 includes a flow tube or cage 162, an upbore barrier 164, a downbore barrier 166, and an occluding device 170 (e.g., a plug or a ball). The upbore barrier 164 is supported in the filler material 120 in the sleeve 110. The flow tube 162 extends from the upbore barrier 164 and is attached by fixtures 168. The downbore barrier 166 is attached to the distal end of the flow tube 162, and the plug 170 is movable inside the flow tube 162 between the upbore barrier 164 and the downbore barrier 166.

[0076] As shown, the flow tube 162 defines one or more port holes 165, which can allow fluid to be circulated at a circulation rate downbore through the autofill float assembly 100 even after the plug 170 forms a fluid tight seal with the downbore barrier 166. The one or more port holes 165 can provide for a low circulation rate so the autofill float assembly 100 can remain unconverted until a predefined pressure from downbore fluid flow is pumped against the plug 170 in the downbore barrier 166 to shift the sleeve 110 as described below.

[0077] The upbore barrier 164 defines a flow opening, and the plug 170 can engage the upbore barrier 164 in response to upbore fluid flow. The upbore barrier 164 can be a seat, a crossbar, or the like and can include flutes, protrusions, gaps, or the like that allow for fluid to pass through the upbore barrier 164 even when the plug 170 is engaged. The plug 170 may be any type of flow-obstructing device, including, but not limited to, a ball.Atty. Dkt. No.: 230-0852WO (6827-PCT)-16-

[0078] The downbore barrier 166 defines a flow opening, and the plug 170 can engage the downbore barrier 166 in response to downbore fluid flow. The downbore barrier 166 can be a seat, such as a ball seat, which prevents fluid from passing in the downstream direction when the plug 170 is engaged.

[0079] During run-in as shown in Fig. 4A, upbore flow can communicate along the selective bypass pathway 108. The plug 170 can engage in the upbore barrier 164 in response to reverse flow upbore through the autofill float assembly 100. In the run-in (autofill) condition shown in Fig. 4A, flow can pass in an upbore direction through downbore barrier 166, the flow tube 162, and the plug 170 engaged in the upbore barrier 164. The upbore flow may not be able to pass the poppet valves 130, which will close due to the upbore flow. Instead, the selective bypass pathway 108 allows flow that is external to the housing 101 to enter through the external ports 104 and aligned bypass ports 114 and to pass further uphole through the autofill float assembly 100.

[0080] When this autofill feature is no longer required, operators increase the flow rate from surface. The increased flow can flow downbore through the bypass ports 114 and aligned external ports 104. If sufficient, the increased flow can open the poppet valves 130 to allow the downbore flow to pass to the shifting assembly 160. The increased downbore flow in turn acts on the plug 170, eventually lodging the plug 170 against the downbore barrier 166 on the shifting assembly 160.

[0081] At this point, the increased downbore flow acts on the sleeve 110. Once a sufficient force is reached, the releasable connection 106 shears the sleeve 110 free to move in the housing’s bore 102. As shown in Fig. 4B, the autofill float assembly 100 then converts to a converted condition. The sleeve 110 shifts in the housing’s bore 102 from an opened condition until the sleeve 110 engages a shoulder 105, which prevents further downbore shifting of the sleeve 110 in a closed condition. Although not shown, a lock (e.g., latch ring, ratcheting lock ring, detent ring, locking taper, groove arrangement, or the like) may lock the sleeve 110 in its downbore position to that it cannot move upbore after shifting. With the sleeve 110 engaging the shoulder 105, the bypass ports 114 in the sleeve 110 are no longer aligned with the external ports 104. As shown in Fig. 4B, the misaligned ports 104, 114 are sealed from one another by the seals 103 on the sleeve 110 engaged in the housing’s bore 102.

[0082] In the end, the shifting assembly 160 can be retained, connected to the sleeve 110. Alternatively, the shifting assembly 160 can be dropped, in whole or part, from the end of the tubing string into the wellbore (or, if present, shoe assembly) depending on the use and position of any releasable connections for the shifting assembly 160. ForAtty. Dkt. No.: 230-0852WO (6827-PCT)-17-example, the increased downbore flow can continue acting on the plug 170 engaged in the downbore barrier 166, and at least the plug 170 can eventually be released from the shifting assembly 160, which would allow for fluid flow in both the upbore and downbore directions through the shifting assembly 160. The downbore barrier 166 can be a releasable ball seat that can release the plug 170 in response to a predetermined force.

[0083] Alternatively, as shown in Fig. 4C, a releasable connection 168b can shear the downbore barrier 166 free from the flow tube 162 when a sufficient force is reached. Now, with the plug 170 and the downbore barrier 166 released, the autofill float assembly 100 can operate in a uni-directional (downbore-only) flow state in which fluid can be channeled through the poppet valves 130 in a downbore-only direction.

[0084] After the hydrostatic pressure within the tubular string reaches a predetermined level or threshold, for example, the plug 170 exerts enough force against the downbore barrier 166 to shear the releasable connection 168b connecting the downbore barrier 166 to the flow tube 162, thereby releasing the downbore barrier 166 from the flow tube 162 as shown in Fig. 4C. After the downbore barrier 166 is released, the downbore barrier 166 is pushed downbore within the wellbore by fluid being pumped through the tubularstring such that the downbore barrier 166 is ejected from the housing 101. The ejection of the downbore barrier 166 permits the poppet valves 130 to operate normally, thereby being normally closed and only opening in response to a downbore pressure differential sufficient to shift the poppets 150 against the springs 158. Cement slurry can be expelled from the tubular string into the surrounding annular area. After the cement slurry is expelled, the poppet valves 130, which are biased to the closed position by the biasing springs 158, prevent reverse flow of the cement slurry so the float assembly acts as a oneway check valve preventing reverse flow or U-tubing of the cement slurry.

[0085] As an alternative shown in Fig. 4D, a releasable connection 168a shears the flow tube 162 free when a sufficient force is reached. With the flow tube 162, the downbore barrier 166, and the plug 170 released, the autofill float assembly 100 can operate in a downbore-only flow condition in which fluid flow can be channeled through the poppet valves 130 in a downbore-only direction.

[0086] As noted above, the subject flow rates can range between 2 to 12 bpm, such as in the intervals of 2 to 4, 5 to 8, or 10 to 12 bpm. An example pressure to shear the releasable connection 106 and to shift the sleeve 110 can be produced when the flow rate is in the range of approximately 5 to 8 bpm. The example pressure can be in the range of approximately 700 to 10,000 psi. Likewise, an example pressure to shear the releasable connection 168a or 168b and to release the flow tube 162 or the downbore barrier 166 canAtty. Dkt. No.: 230-0852WO (6827-PCT)-18-be in the range of approximately 700 to 10,000 psi and / or can be produced when the flow rate is in the range of approximately greater than the 5 to 8 bpm used to free the sleeve 110. These flow rates are merely presented as an example, and other arrangements can be configured to meet the needs of particular implementations. A person of ordinary skill in the art will appreciate that the required pressures can be adjusted by altering the strengths of the releasable connections 106, 168a-b.

[0087] The shifting assemblies 160 can be positioned upbore of the poppet valves 130. For example, Fig. 5A shows the autofill float assembly 100 comparable to Figs. 3A-3D having the shifting assembly 160 disposed in the interior 112 of the sleeve 110 upbore of the poppet valves 130. During run-in, the selective bypass pathway 108 is in an open state, as shown. The selective bypass pathway 108 allows for reverse flow to bypass the poppet valves 130 by communicating through the sleeve’s bypass ports 114 and through the annular area between the housing 101 and sleeve 110. As before, the shifting assembly 160 is activated by an increased flow rate against the plug 170 engaged in the downbore barrier 166, which shifts the sleeve 110, closes off the bypass ports 114, and converts the selective bypass pathway 108 from the opened state to the closed state. As a result, the autofill float assembly 100 is converted from bi-directional operation to downbore-only operation. Components of the shifting assembly 160 may remain in place during cementing, with fluid flow being permitted through the port holes 165 to pass through the autofill float assembly 100 even after the plug 170 forms a fluid tight seal with the downbore barrier 166.

[0088] In another example, Fig. 5B shows the autofill float assembly 100 comparable to Figs. 4A-4D having the shifting assembly 160 disposed in the interior 112 of the sleeve 110 upbore of the poppet valves 130. During run-in, the selective bypass pathway 108 is in an open state, as shown. The selective bypass pathway 108 allows for reverse flow to bypass the poppet valves 130 by communicating through the sleeve’s bypass ports 114 aligned with the housing’s external ports 104. As before, the shifting assembly 160 is activated by an increased flow rate against the plug 170 engaged in the downbore barrier 166, which shifts the sleeve 110, closes off the bypass ports 114, and converts the selective bypass pathway 108 from the opened state to the closed state. As a result, the autofill float assembly 100 is converted from bi-directional operation to downbore-only operation. Again, components of the shifting assembly 160 may remain in place during cementing, with fluid flow being permitted through the port holes 165 to pass through the autofill float assembly 100 even after the plug 170 forms a fluid tight seal with the downbore barrier 166.Atty. Dkt. No.: 230-0852WO (6827-PCT)-19-

[0089] As described in the autofill float assemblies 100 disclosed herein with reference to Figs. 3A through 5B, the shifting assembly 160 is activated by increased flow rate. For the internal bypass arrangement of Figs. 3A-3B and 5A, the selective bypass pathway 108 allows upbore flow to pass inside of the autofill float assembly 100. For the external bypass arrangement of Figs. 4A-4B and 5B, the selective bypass pathway 108 allows upbore flow to pass outside of the autofill float assembly 100.

[0090] The shifting assembly 160 can be activated on demand by increasing the downbore flow rate, which in turn acts on the releasable connection 106 of the sleeve 110. This enables the selective bypass pathway 108 for downbore or upbore (forward or reverse) flow in the poppet valves 130. The shifting assembly 160 open / closes ports, enabling conversion to / from autofill mode to a conventional float equipment mode.Moreover, the autofill float assembly 100 can use the two poppet valves 130, which can be independent of each other and can provide desired redundancy.

[0091] The sliding sleeve 110 is held in place by a releasable connection 106, such as shear screws, shear ring, or similar shear mechanism. In the run-in position, bypass ports on the sleeve 110 are positioned to allow flow to bypass around the poppet valves 130, whether inside or outside the housing 101 , enabling the casing to be filled during run-in (autofill position). As required during operations, when the autofill operation is no longer required, the flow rate is increased to release the releasable connection 106 of the sleeve 110 to the housing 101. When the sleeve 110 is shifted, the bypass ports 114 are closed, eliminating the selective bypass pathway 108 and channeling fluid only through the poppet valves 130 for downbore-only flow as required.

[0092] As can be seen, the autofill float assembly 100 can be converted from the autofill condition to the operational condition in response to fluid flow in the downbore direction. The poppet valves 130 are not obstructed or altered during conversion. When the autofill float assembly 100 is converted, fluid flow can be pumped down the tubing string against the poppet valves 130, which are biased closed and can operate independently of one another. Once fluid pressure above the given poppet valve 130 exceeds the forces exerted by its biasing element 158, the poppet 150 opens, allowing fluid flow therethrough. For example, cement can be pumped from the surface and through the tubing string, forcing open the poppet valves 130 and passing out the lower end of the housing 101 and eventually into the wellbore. The poppet valves 130, operating independently for redundancy, can prevent flow back from the wellbore. After the cement sets, the sleeve 110, the filler material 120, the poppet valves 130, any remaining part of the shiftingAtty. Dkt. No.: 230-0852WO (6827-PCT)-20-assembly 160, and the like can be composed of a millable material and can be drilled out, clearing the tubing string of restrictions.

[0093] Configurations of the present disclosure can be characterized by the following:1. A float assembly (100) for use on a tubing string (22) having a throughbore for fluid flow, the float assembly (100) comprising:a housing (101) configured to couple to the tubing string (22), the housing (101) defining a bore (102) therein communicating with the throughbore of the tubing string (22);a sleeve (110) disposed in the bore (102) and being movable from an opened condition to a closed condition, the sleeve (110) defining a flow passage (122) and defining a bypass port (114), the bypass port (114) with the sleeve (110) in the opened condition being disposed in communication with a bypass pathway (108), the bypass port (114) with the sleeve (110) in the closed condition being disposed out of communication with the bypass pathway (108);at least one valve (130) disposed in the flow passage (122) of the sleeve (110), the at least one valve (130) permitting fluid flow in a downbore direction and preventing fluid flow in an upbore direction; anda shifting assembly (160) disposed in the flow passage (122) of the sleeve (110), the shifting assembly (160) being convertible between a first condition and a second condition, the shifting assembly (160) in the first condition permitting fluid flow in at least the upbore direction, the shifting assembly (160) in the second condition being configured to move the sleeve (110) from the opened condition to the closed condition in response to fluid flow in the downbore direction above a first predetermined level.2. The float assembly (100) of Clause 1 , wherein the bore (102) of the housing (101 ) defines an annular space for the bypass pathway (108) about the sleeve (110); and wherein the bypass port (114) is defined in the sleeve (110) between the at least one valve (130) and the shifting assembly (160), the bypass port (114) on the sleeve (110) in the opened condition being aligned with the annular space and being disposed in communication with the bypass pathway (108), the bypass port (114) on the sleeve (110) in the closed condition being misaligned with the annular space and being disposed out of communication with the bypass pathway (108).3. The float assembly (100) of Clause 1 , wherein the housing (101) defines an external port (104) for the bypass pathway (108) communicating the bore (102) outside the housing (101); and wherein the bypass port (114) defined in the sleeve (110) is defined upbore of the at least one valve (130), the bypass port (114) with the sleeve (110) in the opened condition being aligned with the external port (104) and being disposed inAtty. Dkt. No.: 230-0852WO (6827-PCT)-21-communication with the bypass pathway (108), the bypass port (114) on the sleeve (110) in the closed condition being misaligned with the external port (104) and being disposed out of communication with the bypass pathway (108).4. The float assembly (100) of Clause 1 , 2 or 3, wherein the sleeve (110) comprises a filler material (120) disposed in an interior (112) of the sleeve (110), the filler material (120) defining a portion of the flow passage (122) and supporting the at least one valve (130) and at least a portion of the shifting assembly (160) in the interior of the sleeve (110).5. The float assembly (100) of any one of Clauses 1 to 4, wherein the shifting assembly (160) comprises a plug (170) movable in the shifting assembly (160) and being configured to seal in the downbore direction against a barrier (166) of the shifting assembly (160); and wherein the sleeve (110) comprises a first releasable connection (106) releasably connecting the sleeve (110) in the opened condition in the housing (101), the first releasable connection (106) being configured to release the sleeve (110) to move in the bore (102) in response to fluid flow in the downbore direction above the first predetermined level acting against the plug (170) sealed against the barrier of the shifting assembly (160).6. The float assembly (100) of Clause 5, wherein the shifting assembly is disposed downbore of the at least one valve (130); and wherein the shifting assembly (160) comprises a second releasable connection (168a, 168b) being configured to release at least a portion of the shifting assembly (160) from the sleeve (110) in response to fluid flow in the downbore direction above a second predetermined level acting against the plug (170) sealed against the barrier (166) of the shifting assembly (160).7. The float assembly (100) of any one of Clauses 1 to 4, wherein the shifting assembly (160) comprises:a flow tube (162) having an upbore barrier (164) and having a downbore barrier (166); anda plug (170) movable in the flow tube (162) between the upbore barrier (164) and the downbore barrier (166),the shifting assembly (160) in the first condition having the plug (170) engaged with the upbore barrier (164) and permitting fluid flow in the upbore direction,the shifting assembly (160) in the second condition having the plug (170) engaged with the downbore barrier (166) and at least restricting fluid flow in the downbore direction.8. The float assembly (100) of Clause 7, wherein the shifting assembly is disposed downbore of the at least one valve; and wherein:Atty. Dkt. No.: 230-0852WO (6827-PCT)-22- the flow tube (162) comprises a releasable connection (168a) to the sleeve (110), the releasable connection (168a) being releasable in response to fluid flow in the downbore direction above a second predetermined level acting against the plug (170) engaged in the downbore barrier (166) of the flow tube (162); and / orthe downbore barrier (166) comprises a releasable connection (168b) to the flow tube (162), the releasable connection (168b) being releasable in response to fluid flow in the downbore direction above a second predetermined level acting against the plug (170) engaged in the downbore barrier (166).9. The float assembly (100) of any one of Clauses 1 to 8, wherein the at least one valve (130) comprises a poppet valve at least including:a support (140) disposed in the flow passage (122) and having a seat (145);a biasing element (158) disposed on the support (140); anda poppet (150) disposed on the support (140) and being movable between a closed position and an opened position relative to the seat (145), the poppet (150) being biased by the biasing element (158) toward the closed position, the poppet (150) in the closed position being engaged with the seat (145) and being configured to restrict fluid flow in the upbore direction, the poppet (150) in the opened position being disengaged with the seat (145) and being configured to permit fluid flow in the downbore direction.10. A method used for a tubing string (22) in a wellbore (10), the tubing string (22) having a throughbore for fluid flow, the method comprising:deploying the tubing string (22) in the wellbore (10) while allowing fluid flow in an upbore direction and a downbore direction through a bypass pathway (108) of a float assembly (100) in an opened state, the float assembly (100) disposed on the tubing string (22) and having a sleeve (110), at least one valve (130), and a shifting assembly (160), the sleeve (110) disposed in the float assembly (100), the at least one valve (130) disposed in the sleeve (110), the shifting assembly (160) disposed in the sleeve (110) and disposed downbore of the at least one valve (130);converting the bypass pathway (108) of the float assembly (100) from the opened state to a closed state by:pumping fluid flow in the downbore direction;restricting fluid flow pumped in the downbore direction through the shifting assembly (160);moving the sleeve (110) in the float assembly (100) from an opened condition to a closed condition relative to the bypass pathway (108) of the float assembly (100) in response to fluid flow pumped in the downbore direction to a first predetermined level; andAtty. Dkt. No.: 230-0852WO (6827-PCT)-23- closing off fluid communication of a bypass port (114) in the sleeve (110) with the bypass pathway (108) in response to the sleeve (110) moved to the closed condition; and permitting fluid flow only in the downbore direction through the at least one valve (130) with the bypass pathway (108) of float assembly (100) in the closed condition.11. The method of Clause 10, wherein allowing fluid flow in the upbore direction and the downbore direction through the bypass pathway (108) of the float assembly (100) comprises communicating with the bypass pathway (108) by aligning the bypass port (114) in the sleeve (110), disposed in the opened condition in the float assembly (100), with an annular space for the bypass pathway (108) defined about the sleeve (110) in the float assembly (100).12. The method of Clause 11 , wherein restricting fluid flow pumped in the downbore direction through the shifting assembly (160) comprises sealing a plug (170) in the shifting assembly (160) in the downbore direction against a barrier (166) in the shifting assembly (160); and wherein moving the sleeve (110) in the float assembly (100) from the opened condition to the closed condition comprises applying a force, from fluid flow pumped against the plug (170) and the barrier (166), to the sleeve (110); and optionally wherein sealing the plug (170) in the shifting assembly (160) in the downbore direction against the barrier (166) in the shifting assembly (160) comprises passing fluid flow pumped in the downbore direction to the shifting assembly (160) through at least one of: (a) the bypass pathway (108) to the bypass port (114) disposed upbore of the shifting assembly (160), and (b) the at least one valve (130) disposed upbore of the shifting assembly (160).13. The method of Clause 11 or 12, wherein closing off fluid flow through the bypass port (114) in the sleeve (110) with the bypass pathway (108) in response to the sleeve (110) moved to the closed condition comprises misaligning the bypass port (114) in the sleeve (110) in the closed condition with the annular space.14. The method of Clause 10, wherein allowing fluid flow in the upbore direction and the downbore direction through the bypass pathway (108) of the float assembly (100) comprises communicating with the bypass pathway (108) by aligning the bypass port (114) in the sleeve (110), disposed in the opened condition in the float assembly (100), with an external port (104) for the bypass pathway (108) defined in the float assembly (100).15. The method of Clause 14, wherein restricting fluid flow pumped in the downbore direction through the shifting assembly (160) comprises sealing a plug (170) in the shifting assembly (160) in the downbore direction against a barrier (166) in the shifting assembly (160); and wherein moving the sleeve (110) in the float assembly (100) from theAtty. Dkt. No.: 230-0852WO (6827-PCT)-24-opened condition to the closed condition comprises applying a force, from fluid flow pumped against the plug (170) and the barrier (166), to the sleeve (110); and optionally wherein sealing the plug (170) in the shifting assembly (160) in the downbore direction against the barrier (166) in the shifting assembly (160) comprises passing fluid flow pumped in the downbore direction through the at least one valve (130) to the shifting assembly (160).16. The method of Clause 14 or 15, wherein closing off fluid flow through the bypass port (114) in the sleeve (110) with the bypass pathway (108) in response to the sleeve (110) moved to the closed condition comprises misaligning the bypass port (114) in the sleeve (110) in the closed condition with the external port (104) for the bypass pathway (108) defined in the float assembly (100).17. The method of Clause 10, wherein allowing fluid flow in the upbore direction and the downbore direction through the bypass pathway (108) of the float assembly (100) in the opened condition comprises allowing a plug (170) in the shifting assembly (160) to engage between an upbore barrier (164) and a downbore barrier (166), the plug (170) engaged with the upbore barrier (164) permitting fluid flow in the upbore direction through the shifting assembly (160), the plug (170) engaged with the downbore barrier (166) at least restricting fluid flow in the downbore direction through the shifting assembly (160).

[0094] Any relative terms, such as “above” and “below,” “uphole” and “downhole,” “upbore” and “downbore,” and the like, are used herein without respect to whether the wellbore is vertical or horizontal. These and other relative terms are used to improve understanding. As one skilled in the art will understand, the subject matter of the present disclosure is applicable to horizontal and vertical wells.

[0095] 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 configuration or aspect of the disclosed subject matter can be utilized, either alone or in combination, with any other described feature, in any other configuration or aspect of the disclosed subject matter.

[0096] In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.

Claims

Atty. Dkt. No.: 230-0852WO (6827-PCT)-25- CLAIMS:

1. A float assembly for use on a tubing string having a throughbore for fluid flow, the float assembly comprising:a housing configured to couple to the tubing string, the housing defining a bore therein communicating with the throughbore of the tubing string; a sleeve disposed in the bore and being movable from an opened condition to a closed condition, the sleeve defining a flow passage and defining a bypass port, the bypass port with the sleeve in the opened condition being disposed in communication with a bypass pathway, the bypass port with the sleeve in the closed condition being disposed out of communication with the bypass pathway;at least one valve disposed in the flow passage of the sleeve, the at least one valve permitting fluid flow in a downbore direction and preventing fluid flow in an upbore direction; anda shifting assembly disposed in the flow passage of the sleeve, the shifting assembly being convertible between a first condition and a second condition, the shifting assembly in the first condition permitting fluid flow in at least the upbore direction, the shifting assembly in the second condition being configured to move the sleeve from the opened condition to the closed condition in response to fluid flow in the downbore direction above a first predetermined level.

2. The float assembly of claim 1 , wherein the shifting assembly comprises:a flow tube having an upbore barrier and having a downbore barrier; anda plug movable in the flow tube between the upbore barrier and the downbore barrier,the shifting assembly in the first condition having the plug engaged with the upbore barrier and permitting fluid flow in the upbore direction,the shifting assembly in the second condition having the plug engaged with the downbore barrier and at least restricting fluid flow in the downbore direction.

3. The float assembly of claim 2, wherein the shifting assembly is disposed downbore of the at least one valve; and wherein the flow tube comprises a releasable connection to the sleeve, the releasable connection being releasable in response to fluid flow in the downbore direction above a second predetermined level acting against the plug engaged in the downbore barrier of the flow tube.Atty. Dkt. No.: 230-0852WO (6827-PCT)-26- 4. The float assembly of claim 2, wherein the shifting assembly is disposed downbore of the at least one valve; and wherein the downbore barrier comprises a releasable connection to the flow tube, the releasable connection being releasable in response to fluid flow in the downbore direction above a second predetermined level acting against the plug engaged in the downbore barrier.

5. The float assembly of any one of claims 1 to 4, wherein the at least one valve comprises a poppet valve at least including:a support disposed in the flow passage and having a seat;a biasing element disposed on the support; anda poppet disposed on the support and being movable between a closed position and an opened position relative to the seat, the poppet being biased by the biasing element toward the closed position, the poppet in the closed position being engaged with the seat and being configured to restrict fluid flow in the upbore direction, the poppet in the opened position being disengaged with the seat and being configured to permit fluid flow in the downbore direction.

6. The float assembly of any one of claims 1 to 5, wherein the bore of the housing defines an annular space for the bypass pathway about the sleeve; and wherein the bypass port is defined in the sleeve between the at least one valve and the shifting assembly, the bypass port on the sleeve in the opened condition being aligned with the annular space and being disposed in communication with the bypass pathway, the bypass port on the sleeve in the closed condition being misaligned with the annular space and being disposed out of communication with the bypass pathway.

7. The float assembly of claim 6, wherein the sleeve comprises seals configured to seal the bypass port from the annular space with the sleeve in the closed condition.

8. The float assembly of any one of claims 1 to 5, wherein the housing defines an external port for the bypass pathway communicating the bore outside the housing; and wherein the bypass port defined in the sleeve is defined upbore of the at least one valve, the bypass port with the sleeve in the opened condition being aligned with the external port and being disposed in communication with the bypass pathway, the bypass port on the sleeve in the closed condition being misaligned with the external port and being disposed out of communication with the bypass pathway.

9. The float assembly of claim 8, wherein the sleeve comprises seals configured to seal the bypass port from the external port with the sleeve in the closed condition.Atty. Dkt. No.: 230-0852WO (6827-PCT)-27- 10. The float assembly of any one of claims 1 to 9, wherein the sleeve comprises a filler material disposed in an interior of the sleeve, the filler material defining a portion of the flow passage and supporting the at least one valve and at least a portion of the shifting assembly in the interior of the sleeve.

11. The float assembly of any one of claims 1 to 10, wherein the shifting assembly comprises a plug movable in the shifting assembly and being configured to seal in the downbore direction against a barrier of the shifting assembly; and wherein the sleeve comprises a first releasable connection releasably connecting the sleeve in the opened condition in the housing, the first releasable connection being configured to release the sleeve to move in the bore in response to fluid flow in the downbore direction above the first predetermined level acting against the plug sealed against the barrier of the shifting assembly.

12. The float assembly of claim 11 , wherein the shifting assembly is disposed downbore of the at least one valve; and wherein the shifting assembly comprises a second releasable connection being configured to release at least a portion of the shifting assembly from the sleeve in response to fluid flow in the downbore direction above a second predetermined level acting against the plug sealed against the barrier of the shifting assembly.

13. A method used for a tubing string in a wellbore, the tubing string having a throughbore for fluid flow, the method comprising:deploying the tubing string in the wellbore while allowing fluid flow in an upbore direction and a downbore direction through a bypass pathway of a float assembly in an opened state, the float assembly disposed on the tubing string and having a sleeve, at least one valve, and a shifting assembly, the sleeve disposed in the float assembly, the at least one valve disposed in the sleeve, the shifting assembly disposed in the sleeve and disposed downbore of the at least one valve;converting the bypass pathway of the float assembly from the opened state to a closed state by:pumping fluid flow in the downbore direction;restricting fluid flow pumped in the downbore direction through the shifting assembly;moving the sleeve in the float assembly from an opened condition to a closed condition relative to the bypass pathway of the float assembly inAtty. Dkt. No.: 230-0852WO (6827-PCT)-28- response to fluid flow pumped in the downbore direction to a first predetermined level; andclosing off fluid communication of a bypass port in the sleeve with the bypass pathway in response to the sleeve moved to the closed condition; and permitting fluid flow only in the downbore direction through the at least one valve with the bypass pathway of float assembly in the closed condition.

14. The method of claim 13, wherein allowing fluid flow in the upbore direction and the downbore direction through the bypass pathway of the float assembly comprises communicating with the bypass pathway by aligning the bypass port in the sleeve, disposed in the opened condition in the float assembly, with an annular space for the bypass pathway defined about the sleeve in the float assembly.

15. The method of claim 14, wherein restricting fluid flow pumped in the downbore direction through the shifting assembly comprises sealing a plug in the shifting assembly in the downbore direction against a barrier in the shifting assembly; and wherein moving the sleeve in the float assembly from the opened condition to the closed condition comprises applying a force, from fluid flow pumped against the plug and the barrier, to the sleeve.

16. The method of claim 15, wherein sealing the plug in the shifting assembly in the downbore direction against the barrier in the shifting assembly comprises passing fluid flow pumped in the downbore direction to the shifting assembly through at least one of: (a) the bypass pathway to the bypass port disposed upbore of the shifting assembly, and (b) the at least one valve disposed upbore of the shifting assembly.

17. The method of claim 14, 15, or 16, wherein closing off fluid flow through the bypass port in the sleeve with the bypass pathway in response to the sleeve moved to the closed condition comprises misaligning the bypass port in the sleeve in the closed condition with the annular space.

18. The method of claim 13, wherein allowing fluid flow in the upbore direction and the downbore direction through the bypass pathway of the float assembly comprises communicating with the bypass pathway by aligning the bypass port in the sleeve, disposed in the opened condition in the float assembly, with an external port for the bypass pathway defined in the float assembly.

19. The method of claim 18, wherein restricting fluid flow pumped in the downbore direction through the shifting assembly comprises sealing a plug in the shifting assembly in the downbore direction against a barrier in the shifting assembly; and wherein moving the sleeve in the float assembly from the opened condition to the closed condition comprises applying a force, from fluid flow pumped against the plug and the barrier, to the sleeve.Atty. Dkt. No.: 230-0852WO (6827-PCT)-29- 20. The method of claim 19, wherein sealing the plug in the shifting assembly in the downbore direction against the barrier in the shifting assembly comprises passing fluid flow pumped in the downbore direction through the at least one valve to the shifting assembly.

21. The method of claim 18, 19, or 20, wherein closing off fluid flow through the bypass port in the sleeve with the bypass pathway in response to the sleeve moved to the closed condition comprises misaligning the bypass port in the sleeve in the closed condition with the external port for the bypass pathway defined in the float assembly.

22. The method of any one of claims 13 to 21 , wherein allowing fluid flow in the upbore direction and the downbore direction through the bypass pathway of the float assembly in the opened condition comprises allowing a plug in the shifting assembly to engage between an upbore barrier and a downbore barrier, the plug engaged with the upbore barrier permitting fluid flow in the upbore direction through the shifting assembly, the plug engaged with the downbore barrier at least restricting fluid flow in the downbore direction through the shifting assembly.

23. The method of claim 22, further comprising releasing the restriction of fluid flow pumped in the downbore direction through the shifting assembly in response to fluid flow pumped in the downbore direction to a second predetermined level by:releasing at least the plug from the shifting assembly; andpermitting fluid flow in the upbore direction and the downbore direction through the shifting assembly after the release.

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