Wet shoe wiper plug and related systems and methods

Abstract

A dual wiper plug for wiping a casing string down a wellbore is provided. The dual wiper plug includes a liner wiper and a plug wiper. The liner wiper includes a wiper body coupled to a lock body, liner wiper fins, and an anti-release mechanism. The plug wiper is received and secured in the anti-release mechanism to seal off fluid communication through the liner wiper while the casing string is being wiped. The plug wiper is released from the liner wiper only when the dual wiper plug lands in a subjacent structure, such as a wet shoe sub, to establish fluid communication through the liner wiper, thus preventing premature disengagement of the plug wiper. The anti-release mechanism can include a catch collar and a catch ring that, when engaged by the subjacent structure, releases the catch collar to release the plug wiper and re-establish fluid communication through the liner wiper.

Description

WET SHOE WIPER PLUG AND RELATED SYSTEMS AND METHODSTECHNICAL FIELD

[0001] The technical field generally relates to wet shoe wiper plugs. In particular, the technical field relates to wet shoe wiper plugs with an anti-release mechanism.BACKGROUND

[0002] In hydrocarbon recovery operations, such as well completion or refracturing operations, intentionally forming a wet shoe track may be desirable. After the liner or casing is run into the well, the casing is cemented into place by pumping cement through the casing and into an annulus formed between the casing and the well. To prevent the cement from flowing back up the casing, float tools are used in the toe of the well. In a wet shoe track, the cement is displaced from the float tools so as not to set the float tools at the toe of the well and allowing fluid communication to remain between the casing and the float valve in the toe of the well. A wet shoe track thus allows other operations, such as pumping equipment or fluids down the casing via fluid flow.

[0003] When the cement is pumped through the casing, wipers are used to wipe the casing uphole from the cement to push the cement downhole and remove any excess cement on the casing walls. Some conventional approaches include a lead liner wiper, which is deployed down the casing prior to the cement to clean the liner or casing of debris ahead of the cement and act as a barrier to provide a transition between the cement and the wellbore fluid. The lead or bottom wiper can include a rupturable membrane that ruptures at a predetermined amount of pressure, thus allowing the cement to flow through the lead line wiper and out the float collar. After the predetermined amount of cement has been pumped down through the casing, a follow or top plug wiper can be deployed using displacement fluid. The follow wiper wipes the cement from the casing and lands in the lead liner wiper. When engaged with the lead liner wiper, the follow wiper can displace the lead liner wiper and allow the displacement fluid to flow around the lead and follow wipers and displace the cement in the well toe. However, to accommodate fluid flow paths around the wiper plugs, a wider diameter of casing, sometimes referred to as a bypass, is required in the wet shoe track or the landing collar. Having to accommodate a bypass results in asmaller inner diameter of the casing uphole of the bypass, which restricts fluid flow in a wellbore string that already has limited space for maximizing the inner diameter of the casing. Moreover, such conventional wiper plugs rely on a predetermined pressure in the operating string to facilitate their movement (engagement or disengagement) and reestablish the fluid path. However, irregular pressure in the operating string can result in a premature engagement or disengagement of the liner wiper and the plug wipers, thus reestablishing the fluid path too early or too late to establish a wet shoe track.

[0004] There is thus a need for a technology that overcomes at least some of the drawbacks of what is known in the field.SUMMARY

[0005] According to some broad aspects, there is provided a dual wiper plug comprising: a liner wiper having fluid communication between an uphole end and a downhole end, the liner wiper comprising: a wiper body coupled at a downhole end to a lock body; one or more liner wiper fins disposed around the wiper body; and an antirelease mechanism at the downhole end of the liner wiper; a plug wiper comprising a plug wiper body and a wiper nose configured to be received in the anti-release mechanism; wherein the anti-release mechanism is configured to secure the plug wiper in the liner wiper in a pre-release configuration and seal off the fluid communication through the downhole end of the liner wiper; and wherein the anti-release mechanism is configured to release the plug wiper from the liner wiper in a released configuration when the dual wiper plug lands in a subjacent structure to establish or re-establish the fluid communication through the downhole end of the liner wiper.

[0006] According to some implementations, the anti-release mechanism comprises a catch collar and a catch ring releasably coupled to the lock body around the catch collar in the pre-release configuration, wherein the catch collar is configured to have a smaller inner diameter than the downhole end of the lock body in the pre-release configuration that is expandable in the released configuration when the catch ring is decoupled from the lock body.

[0007] According to some implementations, the catch collar is a retaining collet.

[0008] According to some implementations, the catch collar is at least one mechanical dog.

[0009] According to some implementations, the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 200 psi.

[0010] According to some implementations, the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 400 psi.

[0011] According to some implementations, the catch ring is configured to decouple from the lock body when the catch ring is subjected to a predetermined pressure to shear value against a surface of the subjacent structure.

[0012] According to some implementations, the predetermined pressure to shear value is between about 1400 PSI and about 15000 PSI.

[0013] The dual wiper plug of claim 7, wherein the predetermined pressure to shear value is about 1750 PSI.

[0014] According to some implementations, the predetermined pressure to shear value is at least 5000 PSI.

[0015] According to some implementations, the predetermined pressure to shear value is at least 10000 PSI.

[0016] According to some implementations, the surface of the subjacent structure is a release shoulder configured to reduce an inner diameter of a downhole section of the subjacent structure to a value equal to or greater than an outer diameter of the lock body and less than an outer diameter of the catch ring, such that the catch ring is decoupled from the lock body upon contact with the release shoulder.

[0017] According to some implementations, when in the released configuration, the liner wiper defines a fluid path between the downhole end of the liner wiper and a downhole end of the subjacent structure.

[0018] According to some implementations, the plug wiper body comprises one or more plug wiper fins disposed therearound.

[0019] According to some implementations, an outer surface of the plug wiper comprises a first safe guard surface that is configured to engage with an inner surface of the liner wiper to prevent the plug wiper from flowing out the uphole end of the liner wiper.

[0020] According to some implementations, the first safe guard surface is a grooved plug wiper collar configured to engage with a first grooved surface on the inner surface of the liner wiper.

[0021] According to some implementations, an outer surface of the liner wiper comprises a second safe guard surface that is configured to engage with an inner surface of the subjacent structure to prevent the liner wiper or the dual wiper plug from flowing out an uphole side of the subjacent structure.

[0022] According to some implementations, the second safe guard surface is a grooved liner wiper collar configured to engage with a second grooved surface on the inner surface of the subjacent structure.

[0023] According to some implementations, the subjacent structure is a wet shoe sub.

[0024] According to another aspect, there is provided a dual wiper plug comprising: a liner wiper having fluid communication between and through an uphole end and a downhole end, the liner wiper comprising: a wiper body; one or more liner wiper fins disposed around the wiper body; and a lock body having a catch collar at the downhole end of the liner wiper secured by a catch ring; a plug wiper comprising a plug wiper body and a wiper nose configured to be received in the catch collar; wherein the catch collar is configured to secure the plug wiper in the liner wiper and seal off the fluid communication through the downhole end of the liner wiper; and wherein the catch collar is configured to release the plug wiper upon the dual wiper plug landing in a subjacent structure to establish or re-establish the fluid communication through the downhole end of the liner wiper.

[0025] According to another aspect, there is provided a dual wiper plug for use in establishing a wet shoe track, the dual wiper plug comprising a liner wiper having a hollow tubular body and a plug wiper configured to be retained in the hollow tubular body: wherein the liner wiper is configured to retain the plug wiper in the liner wiper in a pre-release configuration and wipe at least a downhole portion of the wellbore; and wherein the linerwiper is configured to release the plug wiper downhole in a released configuration when the dual wiper plug lands in a subjacent structure.

[0026] According to some implementations, the plug wiper is configured to wipe an uphole portion of a wellbore and land in the liner wiper to plug the hollow tubular body.

[0027] According to some implementations, the liner wiper is configured to prevent the release of the plug wiper downhole until the dual wiper plug lands in the subjacent structure.

[0028] According to another aspect, there is provided a wet shoe assembly comprising the dual wiper plug as defined herein and a wet shoe sub comprising a wet shoe collar, an extension sub coupled to a downhole end of the wet shoe collar, and a plug catcher coupled to the downhole end of the wet shoe collar, wherein the subjacent structure is the wet shoe sub.

[0029] According to another aspect, there is provided a wet shoe assembly comprising: a liner wiper having fluid communication between an uphole end and a downhole end, the liner wiper comprising a wiper body with one or more liner wiper fins disposed therearound and a lock body with a catch collar coupled to a downhole end of the lock body, wherein a catch ring retains the catch collar at a smaller inner diameter than an inner diameter of the lock body; a plug wiper comprising a plug wiper body and a wiper nose configured to be received in the catch collar; and a wet shoe sub comprising a wet shoe collar, an extension sub coupled to a downhole end of the wet shoe collar, and a plug catcher coupled to the downhole end of the wet shoe collar; wherein the catch collar is configured to secure the plug wiper in the liner wiper in a pre-release configuration and seal off the fluid communication at the downhole end of the liner wiper; and wherein the catch ring is configured to release the catch collar to release the plug wiper into the wet shoe sub in a released configuration when the dual wiper plug lands in the wet shoe sub to establish or re-establish the fluid communication at the downhole end of the liner wiper into the uphole end of the wet shoe sub.

[0030] According to some implementations, the plug wiper body comprises one or more plug wiper fins disposed therearound.

[0031] According to some implementations, the catch collar is configured to have a smaller inner diameter than the downhole end of the lock body in the pre-releaseconfiguration that is expandable in the released configuration when the catch ring is decoupled from the lock body.

[0032] According to some implementations, the catch collar is a retaining collet.

[0033] According to some implementations, the catch collar is at least one mechanical dog.

[0034] According to some implementations, the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 200 psi.

[0035] According to some implementations, the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 400 psi.

[0036] According to some implementations, the catch ring is configured to decouple from the lock body when the catch ring is subjected to a predetermined pressure to shear value against a surface of the wet shoe sub.

[0037] According to some implementations, the predetermined pressure to shear value is between about 1400 PSI and about 2800 PSI.

[0038] According to some implementations, the predetermined pressure to shear value is about 1750 PSI.

[0039] According to some implementations, the surface of the wet shoe sub is a release shoulder configured to reduce an inner diameter of a downhole section of the wet shoe sub to a value equal to or greater than an outer diameter of the lock body and less than an outer diameter of the catch ring, such that the catch ring is decoupled from the lock body upon contact with the release shoulder.

[0040] According to some implementations, when in the released configuration, the liner wiper defines a fluid path between the downhole end of the liner wiper and a downhole end of the wet shoe sub.

[0041] According to another aspect, there is provided a wet shoe assembly comprising: a dual wiper plug comprising a liner wiper comprising a body with one or more liner wiper fins disposed therearound and a catch collar; and a plug wiper nestable within the liner wiper; and a wet shoe sub comprising a sub body and a plug catcher disposed inside the sub body, wherein the catch collar is configured to secure the plug wiper in the liner wiperand seal off the fluid communication through the liner wiper; and wherein the catch collar is configured to release the plug wiper into the wet shoe sub upon the dual wiper plug landing in the wet shoe sub to establish or re-establish the fluid communication through the liner wiper and into the wet shoe sub.

[0042] According to some implementations, the plug wiper comprises a plug wiper body having one or more plug wiper fins disposed therearound.

[0043] According to another aspect, there is provided a method of cleaning a shoe track at a bottom of a tubular member in a wellbore, the method comprising: running a plug wiper through an uphole portion of the wellbore with a displacement fluid to displace a cement from the uphole portion; engaging the plug wiper in a liner wiper to form a dual wiper plug and running the dual wiper plug through a downhole portion of the wellbore to displace the cement from the downhole portion; landing the dual wiper plug in a wet shoe sub in the downhole portion; disengaging the plug wiper from the liner wiper such that the plug wiper flows into the wet shoe sub; and displacing the cement downhole of the wet shoe sub with the displacement fluid.

[0044] According to some implementations, the uphole portion includes a drill pipe, a drill string, a work string, and / or a running tool.

[0045] According to some implementations, the downhole portion is a casing or a liner.

[0046] According to some implementations, the plug wiper is a wiper dart.

[0047] According to some implementations, the liner wiper comprises a wiper body coupled at a downhole end to a lock body; one or more liner wiper fins disposed around the wiper body; and an anti-release mechanism at the downhole end of the liner wiper, wherein the anti-release mechanism is configured to engage the plug wiper in the liner wiper in the downhole portion of the wellbore and disengage the plug wiper from the liner wiper when the dual wiper plug lands in the wet shoe sub.

[0048] According to some implementations, the anti-release mechanism comprises a catch collar and a catch ring releasably coupled to the lock body around the catch collar, wherein disengaging the plug wiper from the liner wiper comprises expanding the catch collar and releasing the catch ring from the lock body.

[0049] According to some implementations, expanding the catch collar occurs when a predetermined pressure uphole of the dual wiper plug is exceeded.

[0050] According to some implementations, the predetermined pressure uphold of the dual wiper plug is between about 200 psi and about 400 psi.

[0051] According to some implementations, releasing the catch ring from the lock body occurs when a predetermined pressure to shear value against a surface of the wet shoe sub is exceeded.

[0052] According to some implementations, the predetermined pressure to shear value is one of: between about 1400 psi and about 15000 psi, is about 1750 psi, at least 5000 psi, or at least 10,000 psi.

[0053] According to some implementations, engaging the plug wiper in the liner wiper to form the dual wiper plug further comprises an outer surface of the plug wiper engaging with an inner surface of the liner wiper.

[0054] According to some implementations, the outer surface of the plug wiper is a grooved plug wiper collar that engages with a first grooved surface on the inner surface of the liner wiper.

[0055] According to some implementations, landing the dual wiper plug in the wet shoe sub further comprises engaging an outer surface of the liner wiper with an inner surface of the wet shoe sub.

[0056] According to some implementations, the outer surface of the liner wiper comprises a grooved liner wiper collar configured to engage with a second grooved surface on the inner surface of the wet shoe sub.

[0057] According to another aspect, there is provided a method of cleaning a shoe track at a bottom of a tubular member in a wellbore, the method comprising: running a dual wiper plug comprising a plug wiper disposed within a liner wiper through the wellbore with a displacement fluid to displace a cement from the wellbore; landing the dual wiper plug in a wet shoe sub in the wellbore; disengaging the plug wiper from the liner wiper such that the plug wiper flows into the wet shoe sub; and displacing the cement downhole of the wet shoe sub with the displacement fluid.

[0058] According to some implementations, the liner wiper comprises a wiper body coupled at a downhole end to a lock body; one or more liner wiper fins disposed around the wiper body; and an anti-release mechanism at the downhole end of the liner wiper, wherein the anti-release mechanism is configured to disengage the plug wiper from the liner wiper when the dual wiper plug lands in the wet shoe sub.

[0059] According to some implementations, the anti-release mechanism comprises a catch collar and a catch ring releasably coupled to the lock body around the catch collar, wherein disengaging the plug wiper from the liner wiper comprises expanding the catch collar and releasing the catch ring from the lock body.

[0060] According to some implementations, expanding the catch collar occurs when a predetermined pressure uphole of the dual wiper plug is exceeded.

[0061] According to some implementations, the predetermined pressure uphold of the dual wiper plug is between about 200 psi and about 400 psi.

[0062] According to some implementations, releasing the catch ring from the lock body occurs when a predetermined pressure to shear value against a surface of the wet shoe sub is exceeded.

[0063] According to some implementations, the predetermined pressure to shear value is one of: between about 1400 psi and about 15000 psi, is about 1750 psi, at least 5000 psi, or at least 10,000 psi.

[0064] According to some implementations, the method further comprises engaging the plug wiper in the liner wiper to prevent the plug wiper from flowing uphole.

[0065] According to some implementations, engaging the plug wiper in the liner wiper comprises an outer surface of the plug wiper engaging with an inner surface of the liner wiper.

[0066] According to some implementations, the outer surface of the plug wiper is a grooved plug wiper collar that engages with a first grooved surface on the inner surface of the liner wiper.

[0067] According to some implementations, landing the dual wiper plug in the wet shoe sub further comprises engaging an outer surface of the liner wiper with an inner surface of the wet shoe sub.

[0068] According to some implementations, the outer surface of the liner wiper comprises a grooved liner wiper collar configured to engage with a second grooved surface on the inner surface of the wet shoe sub.

[0069] In some implementations, the dual wiper plug and / or wet shoe assembly has one or more features as defined herein and / or as described or illustrated herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The attached figures illustrate various features, aspects and implementations of the technology described herein.

[0071] FIG. 1 is a schematic view of a well completion system showing a casing string being cemented in a wellbore;

[0072] FIG. 2 is an expanded side view of a wet shoe assembly according to one implementation, showing a wet shoe sub and a dual wiper plug having a liner wiper and a plug wiper;

[0073] FIG. 3 is a side cross-sectional view of the wet shoe assembly shown in FIG. 2, showing the dual wiper plug landed in the wet shoe sub in a pre-release configuration;

[0074] FIG. 4 is a side cross-sectional view of the wet shoe assembly shown in FIG. 2, showing the dual wiper plug in a released configuration with the plug wiper having flowed downhole into the wet shoe sub;

[0075] FIG. 5 is a side cross-sectional view of the wet shoe sub of the wet shoe assembly shown in FIG. 2, the wet shoe sub having a wet shoe collar, an extension sub, and a plug catcher;

[0076] FIG. 6 is a side cross-sectional view of a wet shoe collar of the wet shoe sub shown in FIG. 5;

[0077] FIG. 7 is an enlarged view of the wet shoe sub shown in FIG. 5, showing the connection between the wet shoe collar, the extension sub, and the plug catcher;

[0078] FIG. 8A is a cross-sectional side view of the liner wiper of the wet shoe assembly shown in FIG. 2, showing a wiper body, a lock body, and an anti-release mechanism in a pre-release configuration;

[0079] FIG. 8B is a cross-sectional side view of the liner wiper of the wet shoe assembly shown in FIG. 2, showing the anti-release mechanism in a released configuration;

[0080] FIG. 9A is a side view of the liner wiper shown in FIG. 8A with the anti-release mechanism in the pre-release configuration;

[0081] FIG. 9B is a side view of the liner wiper shown in FIG. 8B with the anti-release mechanism in the released configuration;

[0082] FIG. 10 is a side view of the plug wiper of the wet shoe assembly shown in FIG. 2;

[0083] FIG. 11 is a side cross-sectional view of the plug wiper shown in FIG. 10;

[0084] FIG. 12 is an enlarged view of the wet shoe assembly shown in FIG. 3, showing the relationship between the wet shoe sub, the liner wiper, and the plug wiper in the landed, pre-released configuration; and

[0085] FIG. 13 is an enlarged view of the wet shoe assembly shown in FIG. 4, showing the relationship between the wet shoe sub, the liner wiper, and the plug wiper in the landed, released configuration.DETAILED DESCRIPTION

[0086] Techniques described herein relate to systems, devices and methods for the recovery of hydrocarbon material from a subterranean formation. However, it is understood that the systems, devices, and methods described herein can also be used in other applications, such as in geothermal well construction, etc.

[0087] As will be explained below in relation to various implementations, the present disclosure also relates to well completion, and more specifically, to the process of cementing the casing within the wellbore to create a wet shoe track. “Wet shoe track” in the present disclosure means a partial or complete absence of cement in the shoe track of the wellbore. In other words, there is a partial or complete absence of cement in the casing section between adjacent pieces of float equipment, such as between a float collar and a float shoe.

[0088] The present disclosure also provides for a wet shoe assembly, which can be adapted for downhole deployment within a wellbore extending into a hydrocarbon- containing reservoir to cement the casing within the wellbore and facilitate the creation of a wet shoe track. The wet shoe assembly can include a wet shoe sub and a dual wiper plug. The dual wiper includes a liner wiper with a body (wiper body and lock body) having a hollow interior. The lock body is configured to releasably receive the plug wiper and includes an anti-release mechanism that prevents the release of the plug wiper (thereby sealing off fluid communication between an uphole side of the dual wiper plug and a downhole side of the dual wiper plug) until the dual wiper plug has landed in the wet shoe sub. Once the plug wiper is released into the wet shoe sub, a fluid path through the hollow interior of the liner wiper and into the wet shoe sub is established ( / .e., fluid communication between the uphole side of the dual wiper plug and the downhole side of the dual wiper plug is established or re-established). Having a fluid path through the interior of the liner wiper facilitates a wider inner diameter of the flow path areas in the wet shoe assembly and / or allows a smaller overall diameter of the wet shoe sub. For the avoidance of doubt, the internal components of the well completion assembly (such as, the work string, running tool, casing string, etc.) define an inner passageway along their length and therefore, fluid communication refers to fluid flow through the inner passageway from the surface to the toe of the well.

[0089] In some implementations, the wet shoe assembly and / or the dual wiper plug can be configured to be used with a long-string application. In such implementations, the dual wiper plug includes a liner wiper and a plug (which may or may not include fins, as there is no section uphole of the liner wiper to wipe) that are deployed together ( / .e., deployed from surface with the plug already installed in the liner wiper in the pre-released configuration).

[0090] In some implementations, the portion of the wellbore that is uphole of the liner wiper before cementing can be referred to as the uphole portion and the portion of the wellbore that is downhole from the liner wiper may be referred to as the downhole portion. The plug wiper optionally wipes cement in the uphole portion ( / .e., the portion of the wellbore uphole of the liner wiper at the onset of cementing) and the liner wiper or the dual wiper wipes cement in the downhole portion ( / .e., the portion of the wellbore downhole of the liner wiper at the onset of cementing). For the avoidance of doubt, uphole anddownhole refer to the relative position of the element in relation to the surface or the toe of the well, respectively.

[0091] Referring to FIG. 1 , a well completion system 10 for cementing a casing string 12 into a wellbore 14 extending into an underground reservoir 5, is shown. The casing string 12 comprises a length of pipe (such as, a casing or liner), typically a series of tubulars assembled at the surface 18 before being lowered into the wellbore 14. The casing string 12 (which can also be referred to as the wellbore string) may also include a liner hanger 15 at the uphole end, float shoe elements, such as a float collar 20 and float shoe 22, closer to the downhole end or toe 16, and other functional tubular elements, such as fracturing sleeves, dispersed at various intervals along the length of casing string 12. The casing string 12 may extend from the surface 18, or may be hung from a pre-existing casing, such as a surface casing 13 (as shown in FIG. 1). When hung from a pre-existing casing, the casing string 12 may be deployed downhole attached to, via the liner hanger 15, to a running tool 11 , suspended by and fluidly attached to a work string 19, the liner hanger 15 having slips 17 for anchoring the casing string 12 to the pre-existing casing, such as the surface casing 13. The work string 19 may include a drill pipe or drill string. For long string applications, where the casing string 12 extends from the surface, a work string 19, running tool 11 , and liner hanger 15 may not be required.

[0092] The float shoe 22 is installed in the toe 16 of the casing string 12 and includes an aperture and check valve that allows the fluid to pass through in only one direction. The float collar 20 is installed uphole from the float shoe 22 to create a wet shoe track 24 in the space therebetween. The float collar 20 and float shoe 22 each include a check valve that prevents fluid being pumped downhole from flowing back uphole {e.g., U-tubing). In some implementations, the check valve or valves can have a cracking pressure of between about 15 and about 50 psi, or in some implementations, about 25 psi.

[0093] Still referring to FIG. 1 , the well completion system 10 can further include a wet shoe assembly. The wet shoe assembly includes a wet shoe sub 26, the liner wiper 28, and the plug wiper 30. At the onset of well completion the liner wiper 28 is connected to the downhole end of the running tool 11 , and the plug wiper 30 is held at or near the surface 18. As described herein, following cementing, the plug wiper 30 is released, and wipes the inner passageway uphole of the liner wiper 28 (e.g. the inner surfaces of the work string 19 and the running tool 11) and engages the liner wiper 28 to form a dualwiper, which travels down the casing string 12 to wipe the internal surfaces thereof ( / .e., wiping the portion of the wellbore 14 downhole of the liner wiper 28 and uphole of the wet shoe sub 26) before engaging the wet shoe sub 26. The wet shoe assembly association of the dual wiper and the wet shoe sub allows for the creation of the wet shoe track 24, which provides for an open flow path for the displacement fluid behind the dual wiper plug to flow between the float collar 20 and the float shoe 22 to partially or fully displace the cement in the shoe track and flow out of the float shoe 22 and into the annulus to create the wet shoe track 24. In other words, the wet shoe assembly is configured to allow the over displacement of the cement to clear the casing string between the float collar 20 and float shoe 22, resulting in a desired wet shoe track 24. For example, in some implementations, a minimum of between about 5 feet and about 10 feet of a wet shoe track 24 can be established uphole of the toe 16. When 500 feet of casing is being cemented, the amount of cement to be displaced to establish 500 feet of casing cement and about 5 to 10 feet of a wet shoe track 24 can then be calculated and the determined volume of displacement fluid is then pumped into the wellbore uphole from the dual wiper plug. In other implementations, larger wet shoe tracks 24 can be establish, such as up to 500 feet.

[0094] In some implementations, the amount of cement being displaced can be equal to a minimum amount required to establish fluid communication within the wet shoe track 24 for the desired length of the wet shoe track 24. For example, when 20,000 feet of casing is being cemented and the operator wants to establish 100 feet of wet shoe track 24, the amount of cement displaced will be equal to about 0.5% of the total cement being pumped downhole. If a larger wet shoe track 24 is desired, then more cement should be displaced from the wet shoe track 24. For example, to establish a 500-foot wet shoe track 24 on a 10,000-foot casing operation, about 5% of the cement being pumped downhole must be displaced from the wet shoe track 24. In some implementations, the amount of cement being displaced within the wet shoe track 24 can be between about 0.1% and about 10% of the total cement being pumped downhole to cement the casing string 12.

[0095] During the cementing operation, a predetermined amount of cement is pumped down the work string 19, through the running tool 11 , and subsequently through the casing string 12. In some implementations, after all the cement is pumped into the work string 19, the plug wiper 30 is deployed from surface 18 into the work string 19 and is pushed, usingdisplacement fluid, downhole through the work string 19 and the running tool 11 and towards the liner wiper 28 to displace the cement and wipe an internal diameter of the work string 19 and the running tool 11 uphole of the liner wiper 28. The plug wiper 30 lands in the liner wiper 28 in close proximity to the uphole end of the casing string 12 being cemented in place (for example, at the downhole end of the running tool 11). In other implementations, such as the long-string application, the dual wiper plug including the plug wiper 30 (with or without plug wiper fins) and the liner wiper 28 are deployed together from surface into the casing string as the dual wiper plug.

[0096] After landing within the liner wiper 28, the plug wiper 30 is secured within the liner wiper 28 by a lock body with an anti-release mechanism that only releases the plug wiper 30 when the dual wiper plug ( / .e., the plug wiper 30 landed in the liner wiper 28) lands in the wet shoe sub 26. More regarding the lock body and operation of the assembly will be described below.

[0097] The dual wiper plug is pushed downhole towards the wet shoe sub 26 near the toe 16 of the wellbore 14 using displacement fluid and displaces and wipes the cement in the casing string 12. The cement flows through the wet shoe sub 26, through the float collar 20, and out of the casing string 12 through the float shoe 22. After flowing out the float shoe 22, the cement flows up through an annulus between an outer surface of the casing string 12 and the wellbore 14 to secure the casing string 12 in the wellbore 14.

[0098] Once the dual wiper plug lands in the wet shoe sub 26, the anti-release mechanism on the lock body of the liner wiper 28 releases the plug wiper 30 from the liner wiper 28. Once the plug wiper 30 is released from the liner wiper 28, the displacement fluid (or other fluid flowing behind or uphole from the dual wiper plug) pushes the liner wiper 28 into the wet shoe sub 26 and the plug wiper 30 is received in a plug catcher in the wet shoe sub 26 to prevent the plug wiper 30 from flowing into the float collar 20. Once the plug wiper 30 flows into the wet shoe sub 26, fluid flow of the displacement fluid is reestablished through a center of the liner wiper 28 and around the plug wiper 30 within the wet shoe sub 26. The displacement fluid can then flow through the float collar 20 and float shoe 22 to clear and establish the wet shoe track 24.

[0099] Referring now to FIGs. 2 to 4, a wet shoe assembly 100 according to one implementation is shown. The wet shoe assembly 100 includes a wet shoe sub 110, a liner wiper 120, and a plug wiper 130, which can also be referred to as a wiper dart. Asshown in FIG. 2, the plug wiper 130 is configured to wipe the work string and the running tool, which typically have a smaller inner diameters than the casing string ( / .e., the diameter of the tubulars, liner, liner hanger, etc.) being cemented. Once the work string and running tool are wiped, the plug wiper 130 lands in the liner wiper 120, located in close proximity to an uphole end of the casing string being cemented. Once landed in the liner wiper 120, the plug wiper 130 and the liner wiper 120 form a dual wiper plug that is configured to wipe the casing string from the initial position of the liner wiper 120 downhole to the wet shoe sub 110 where it lands, as shown in FIG. 3. The liner wiper 120 releases the plug wiper 130 ( / .e., the liner wiper 120 is in the released configuration), which flows downhole into a plug catcher 116 (FIG. 4) to re-establish fluid communication between the casing string uphole from the dual wiper plug and the wet shoe sub 110, as shown in FIG. 4, such that the fluid behind or uphole from the dual wiper plug can flow into and through the wet shoe sub 110.

[0100] Referring now to FIGs. 5 to 7, the wet shoe sub 110 can be adapted for downhole deployment within a wellbore extending into the hydrocarbon-containing reservoir. The wet shoe sub 110 is shaped, sized and adapted to be integrated as part of a casing string. In some implementations, the wet shoe sub 110 is disposed as part of the casing string uphole from the float equipment, such as a float collar or float shoe. Alternatively, the wet shoe sub 110 can be used or disposed downhole as part of the casing string and associated with or be a part of one or more float equipment, such as a float collar.

[0101] The wet shoe sub 110 includes a sub body having an inlet 110a and an outlet 110b. In the exemplary implementation, the sub body includes a wet shoe collar 112 (which can also be referred to as a “sub”) and an extension sub 114. In the exemplary embodiment, the wet shoe collar 112 is a tubular body having an uphole end and a downhole end with fluid communication provided therebetween. In the exemplary implementation, an outer surface of the downhole end of the wet shoe collar 112 is coupled to an inner surface of an uphole end of the extension sub 114. However, it is also contemplated that the wet shoe collar 112 and the extension sub 114 can be formed of an integral piece. Before the dual wiper plug has landed in the wet shoe sub 110 and after the plug wiper 130 has been released from the liner wiper 120, the wet shoe sub 110 provides for fluid communication between the inlet 110a and the outlet 110b. After thedesired fluid, such as cement, has flowed through the wet shoe sub 110, the inlet 110a of the wet shoe sub 110 is configured to catch the dual wiper plug.

[0102] In the exemplary implementation, the wet shoe sub 110 further includes a plug catcher 116 coupled to the wet shoe collar 112 at the downhole end thereof. An inner surface of the downhole end of the wet shoe collar 112 is coupled to an uphole end of the plug catcher 116, such that the plug catcher 116 is positioned within, for example concentrically within, the extension sub 114. However, it is also contemplated that the wet shoe collar 112 and the plug catcher 116 can be formed of an integral piece.

[0103] The plug catcher 116 includes flow path apertures or perforations 118 that provide fluid communication between the plug catcher 116 and the extension sub 114. Accordingly, when the interior flow path of the wet shoe collar 112 is open, the fluid flows through the downhole end of the wet shoe collar 112, into the plug catcher 116, out the perforations 118 into the extension sub 114, and out the downhole end of the extension sub 114 ( / .e., the outlet 110b of the wet shoe sub 110) into the casing string towards the float equipment.

[0104] With specific reference to FIGs. 6 and 7, the inner surface of the tubular body of the wet shoe collar 112 can have varying inner and outer diameters. The wet shoe collar 112 includes an uphole section 112a having an uphole inner diameter I DA and an uphole outer diameter ODA, an intermediate section 112b having an intermediate inner diameter IDB and an intermediate outer diameter ODB, and a downhole section 112c having a downhole inner diameter I De and a downhole outer diameter ODc.

[0105] The uphole inner diameter I DA can vary and is sized at the inlet 110a of the wet shoe sub 110 to receive the downhole end of the liner wiper 120 and direct the liner wiper 120 towards the downhole end of the wet shoe collar 112. In some implementations, the uphole inner diameter I DA can be configured to receive the liner wiper fins 126 on the liner wiper 120 without deformation. In the exemplary implementation, the uphole section 112a of the wet shoe collar 112 includes a guide shoulder 150 at the interface between the uphole section 112a and the intermediate section 112b to guide the downhole end of a lock body 124 of the liner wiper 120 into the intermediate section 112b of the wet shoe collar 112.

[0106] The intermediate section 112b of the wet shoe collar 112 has an intermediate inner diameter I DB that is sized to receive the lock body 124 of the liner wiper 120. In the exemplary embodiment, the solid outer diameter ODs of the liner wiper 120 ( / .e., the outer diameter of the solid portion of the liner wiper 120, as shown in FIG. 9A) is less than the intermediate inner diameter I DB of the intermediate section 112b of the wet shoe collar 112 and greater than the downhole inner diameter I De of the downhole section 112c of the wet shoe collar 112, such that the liner wiper 120 can flow into the intermediate section 112b and engage a release shoulder 152 at the interface between the intermediate section 112b and the downhole section 112c to retain the liner wiper 120 in the intermediate section 112b. The deformable outer diameter ODD of the liner wiper 120 ( / .e., the outer diameter of the deformable liner wiper fins 126, as shown in FIG. 9A) is greater than the solid outer diameter ODs of the liner wiper 120. In some implementations, the deformable outer diameter ODD of the liner wiper 120 is larger than the intermediate inner diameter I DB of the intermediate section 112b of the wet shoe collar 112 to account for the deformation of the liner wiper fins 126 ( / .e., the liner wiper fins 126 deform to allow the liner wiper 120 to flow through the intermediate section 112b to engage with the release shoulder 152. As discussed below, the release shoulder 152 is configured to engage with an anti-release mechanism 128 on the liner wiper 120.

[0107] In the exemplary embodiment, the wet shoe collar 112 and the extension sub 114 are coupled by means of an interlocking configuration and interference fit. However, as is understood by the skilled artisan, any means of coupling known in the art can be used to couple the downhole end of the wet shoe collar 112 to the uphole end of the extension sub 114 or the wet shoe collar 112 and the extension sub 114 can form an integral piece.

[0108] In the exemplary implementation, the downhole end of the wet shoe collar 112 has a coupling surface 142 that is configured to couple to a coupling flange 144 on the extension sub 114. In the exemplary implementation, the coupling surface 142 has a downhole outer diameter ODc that is configured to be received within the inner diameter of the coupling flange 144 extension sub 114, for example in an interlocking configuration. As is best shown in FIG. 7, the coupling surface 142 and the coupling flange 144 have corresponding surfaces that are configured to securely engage with each other to securely couple and seal the wet shoe collar 112 and the extension sub 114. In the exemplaryimplementation, the wet shoe sub 110 further includes a gasket 146, such as an o-ring, between the wet shoe collar 112 and the extension sub 114. In some implementations, the wet shoe collar 112 includes a groove 148 configured to receive the gasket 146 between the wet shoe collar 112 and the extension sub 114. As is understood by the skilled artisan, a seal can be provided between the wet shoe collar 112 and the extension sub 114 to prevent the fluid being run down the wellbore string from leaking into or out of the walls of the wet shoe sub 110.

[0109] Referring now to FIGs. 8A to 9B, the liner wiper 120 includes a wiper body 122 coupled at a downhole end thereof to a lock body 124. When the plug wiper 130 is not landed in the liner wiper 120, the liner wiper 120 provides fluid communication between the uphole end and the downhole end ( / .e., the liner wiper 120 defines an inner passageway that maintains fluid flow through the casing string when the plug wiper 130 is not landed in the liner wiper 120). The wiper body 122 includes one or more liner wiper fins 126 disposed around the wiper body 122.

[0110] The lock body 124 includes an anti-release mechanism that is configured to catch the plug wiper 130 in a pre-release configuration and prevent the plug wiper 130 from flowing out the downhole end of the liner wiper 120 prior to the dual wiper plug landing in the subjacent structure, such as a landing collar or wet shoe sub 110 ( / .e., preventing the pre-release of the plug wiper 130). In the exemplary implementation, the anti-release mechanism includes a catch collar 154 at the downhole end thereof that is configured to catch the plug wiper 130 in the liner wiper 120 when the plug wiper 130 lands or flows into the liner wiper 120.

[0111] The catch collar 154 includes protrusions 154a that reduce the outlet internal diameter I Do of the outlet of the liner wiper 120 and a catch ring 156 securing the catch collar 154 in the pre-release configuration ( / .e., prior to landing in the subjacent structure), as shown in FIG. 12. The catch ring 156 is releasably secured to the outer surface of the catch collar 154 with a frangible member 158, such as a shear pin. When the plug wiper 130 lands in the catch collar 154 of the lock body 124, the protrusion 154a prevents the plug wiper from flowing out of the downhole end of the lock body 124 and the wiper nose 136 of the plug wiper 130 seals off the fluid communication at the downhole end of the liner wiper 120, thus sealing off fluid communication through the wiper body 122 of the liner wiper 120. Once the plug wiper 130 has landed in the liner wiper 120, the dual wiperplug can move downhole within the casing string until it reaches the wet shoe sub 110. In some implementations, the lock body 124 includes a sealing mechanism 140, such as an o-ring, that provides a seal between the lock body 124 and the wet shoe collar 112. As is understood by the skilled artisan, a seal can be provided between the wet shoe collar 112 and the lock body 124 to prevent the fluid being run down the casing string from leaking out around the dual wiper plug and / or from creating the pressure required to release the anti-release mechanism when the liner wiper 120 engages the release shoulder 152.

[0112] In some implementations, safe guard surfaces can be provided on an outer side of the liner wiper 120, an outer surface of the plug wiper 130, an inner surface of the liner wiper 120, and / or an inner surface of the wet shoe collar 112. The safe guard surfaces can be provided to prevent the liner wiper 120 and / or the plug wiper 130 from flowing out of the wet shoe collar 112 and back uphole in the wellbore. In the exemplary embodiment, the safeguard surfaces include an inner surface of the wiper liner 120, which in the exemplary implementation is an inner surface of the lock body 124, having a first grooved surface 160 that is configured to engage with a grooved plug wiper collar 162 on an outer surface of the plug wiper 130. The liner wiper 120 can also include a grooved liner wiper collar 164 around the wiper body 122 that is configured to engage with a second grooved surface 166 of the intermediate section 112b of the wet shoe collar 112, as shown in FIG. 12.

[0113] When the dual wiper plug lands in the wet shoe sub 110, the catch ring 156 on the lock body 124 of the liner wiper 120 abuts or comes into contact with the release shoulder 152. When the pressure from the displacement fluid following ( / .e., behind or uphole thereof) the dual wiper plug exceeds a predetermined threshold, the frangible members 158 are configured to break after a predetermined amount of upward force or pressure, allowing the wiper body 122 and the lock body 124 to move downhole from the catch ring 156, thus freeing the catch collar 154 (Figures 8B, 9B, and 13). For clarity, the frangible members 158 are configured to break when catch ring 156 of the lock body 124 has a downhole or downward directed force exerted on it from pressure from fluids uphole of the liner wiper 120. As the lock body 124 is pushed downhole against the release shoulder 152, the resulting pressure causes the frangible members 158 to break, allowing the lock body 124 to move downhole while the catch ring 156 remains in position against the release should 152. This allows the catch collar 154 to move into the downhole section112c of the wet shoe sub 112 and expand. The catch collar 154 is configured to expand under a predetermined amount of pressure when displaced from the catch ring 156, thus allowing the wiper nose of the plug wiper 130 to flow out the downhole end of the liner wiper 120. Consideration to the length of the catch collar 154 (or the clearance area of the catch collar 154) should be given when determining the position of the release shoulder 152. In other words, in some implementations, the length of the downhole section 112c is equal to or greater than the length of the catch collar 154, thus allowing the catch collar 154 to expand within the downhole section 112c of the wet shoe sub 112.

[0114] The catch ring 156 is configured to only release the catch collar 154 in response to contact between the catch ring 156 and the release shoulder 152. In some implementations, the frangible members 158, such as shear screws, are configured to release the catch ring 156 when the pressure in the casing string (uphole of the dual wiper) exceeds a predetermined pressure to shear of between about 1000 psi and about 10,000 psi or, in some implementations, from 1000 psi to 3,000 psi. For example, the number and type (strength of pin force) of frangible members 158 coupling the catch ring 156 to the lock body 124 can be varied to determine the predetermined pressure to shear. In some implementations, between 4 and 8 frangible members 158 having a pin force of between about 1000 Ibf and about 2000 Ibf for a piston area of between about 3 and about 5 square inches can be used to determine the desired pressure to shear value (predetermined pressure to shear). For example, using 4 to 8 frangible members 158 having a pin force of 1400 Ibf for a piston area of about 4 square inches provides pressure to shear values of between about 1400 psi and about 2800 psi. In the exemplary implementation, five frangible members 158 having a pin force of 1400 Ibf over about 4 square inches were used to provide a pressure to shear value of about 1750 psi before releasing the catch ring 156 from the lock body 124.

[0115] Similarly, the catch collar 154 is configured to only release the plug wiper 130 when the pressure of the displacement fluid uphole of the dual wiper reaches a predetermined pressure. In some implementations, the catch collar 154 can be configured to release the plug wiper 130 at a pressure that is less than the pressure to shear value of the catch ring 156, such as between 200 and 800 psi. In the exemplary implementation, the catch collar 154 is configured to release the plug wiper 130 when the pressure uphole of the dual wiper on the plug wiper 130 reaches about 400 psi.

[0116] Referring now to FIGs. 10 and 11 , the plug wiper 130 includes a plug wiper body 132 having one or more plug wiper fins 134 disposed therearound and a wiper nose 136 configured to be received in the catch collar 154. Once released from the liner wiper 120, the plug wiper 130 flows into the plug catcher 116 of the wet shoe sub 110 and reestablishes fluid communication between the liner wiper 120 and the wet shoe sub 110. The plug wiper fins 134 are made of a deformable material, such as rubber, such that they can deform to flow through the downhole end of the liner wiper 120 and expand in the perforations 118 in the plug catcher 116 to prevent the plug wiper 130 from flowing out of the wet shoe sub 110 and into the float equipment. In some implementations, such as for use in a long-string application where the plug wiper 130 is preinstalled in the liner wiper 120, the plug wiper body 132 can be devoid of plug wiper fins, as they are not required to wipe the uphole section of the wellbore.

[0117] As is understood by the skilled artisan, the dimensions of the plug wiper 130, including the length, the outer diameter, and / or the size and number of plug wiper fins 134, can be optimized to fit within and wipe any size of tubular member, such as casing, drill pipe, drill string, liners, etc. In the exemplary implementation, the plug wiper 130 includes a first fin 134i, second fin 1342, a third fin 134s, and a fourth fin 1344. The first fin 134i (downhole fin) and the fourth fin 1344 (uphole fin) can have the same fin outer diameter ODFI. In some implementations, the downhole fin and the uphole fin have the largest outer diameter. In the exemplary implementation, the second fin 1342 has the smallest fin outer diameter ODF2 and the third fin 134s has a slightly smaller outer diameter (not shown) than the fin outer diameter ODFI of the first fin 134i and the fourth fin 1344. Consideration should be given to the pressure exerted by the deformed plug wiper fins 134 when wiping the tubular member upstream of the liner wiper 120. For example, the fin outer diameter ODFI of the largest fins (such as the uphole and downhole fins) can be about 5% to about 30% larger than the largest inner diameter along the length of the work string and running tool (or uphole portion) being wiped. Similarly, the fin outer diameter ODF2 of the smallest fin can be about 5% to about 30% larger than the inner diameter of the smallest inner diameter along the length of the work string and running tool (or uphole portion) being wiped. Accordingly, the shape and position of the plug wiper fins 134, such as the fin outer diameter ODFI, ODF2 can be optimized for use in any system.

[0118] The wiper nose 136 can also have various dimensions, including width, length, and shape. In the exemplary implementations, the wiper nose 136 has a tapered shape. As is shown best in FIG. 12, the tapered angled of the wiper nose 136 substantially matches the tapered angle of the protrusion 154a on the catch collar 154. When the catch ring 156 is sheared from the lock body 124, the dual wiper plug ( / .e., the plug wiper 130 landed in the liner wiper 120) moves downhole into the downhole section 112c of the wet shoe collar 112 and the pressure behind the plug wiper 130 pushes the wiper nose 136 of the plug wiper 130 into the protrusion 154a on the catch collar 154, causing the catch collar 154 to deform slightly and release the plug wiper 130.

[0119] Other shapes and configurations of the wiper nose 136 are also contemplated, such as a ball shape. In some implementations, the wiper nose 136 can be hollow, for example to save material and / or reduce weight. In some implementations, the wiper nose 136 includes a sealing mechanism 138 on an outer surface thereof, to provide a seal between the lock body 124 of the liner wiper 120 and the plug wiper 130 (thus sealing off all fluids behind the plug wiper 130 when the plug wiper 130 is landed in the liner wiper 120 and providing the necessary pressure to push the plug wiper 130 past the catch collar 154).

[0120] Referring now to FIGs. 12 and 13, as can be seen, the catch collar 154 of the anti-release mechanism secures the plug wiper 130 in the liner wiper 120 in a pre-release configuration (Figure 12), thus sealing off fluid communication through the downhole end of the liner wiper 120 and forming a dual wiper plug. When the dual wiper plug lands in a subjacent structure, such as the intermediate section 112b of the wet shoe collar 112 of the wet shoe sub 110, the catch ring 156 of the anti-release mechanism is sheared from the lock body 124 of the liner wiper 120, allowing the liner wiper 120 to flow downhole into a downhole section of the subjacent structure, such as the downhole section 112c of the wet shoe collar 112 of the wet shoe sub 110. Once in the downhole section 112c of the wet shoe collar 112, the catch collar 154, no longer being restrained by the catch ring 156, can expand to allow the plug wiper 130 to flow out of the liner wiper 120.

[0121] As is understood in the art, other forms of anti-release mechanisms can be used. In the exemplary implementation, the catch collar 154 is a retaining collet. However, other forms of retaining mechanisms can be used, such as the catch collar including one or more mechanical dogs. The mechanical dog can be secured by a catch ring or sheathto narrow the outlet internal diameter I Do of the outlet of the liner wiper 120 until the catch ring or sheath is displaced from the lock body 124 of the liner wiper 120, thus freeing the mechanical dog.

[0122] There is also provided a method of cementing a wellbore to establish a desired wet shoe according to one implementation. The method can be implemented using the wet shoe assembly 100 and / or the dual wiper plugs ( / .e., the liner wiper 120 and the plug wiper 130) described herein. During the cementing operation, a landing collar, such as the wet shoe sub 110, is deployed to a desired location in the wellbore, such as in the casing string uphole from the float equipment.

[0123] In some implementations, the liner wiper 120 is deployed in a running tool used to deploy the downhole equipment. A predetermined amount of cement slurry is pumped down through the work string and into the casing string. The plug wiper 130 is deployed from the surface into the work string following the cement. Using displacement fluid, the plug wiper 130 is pushed downhole through the work string while simultaneously pushing the cement downhole within the work string, wiping the internal surfaces of the work string. The cement slurry flows through the work string, including through the running tool, and through the hollow interior of the liner wiper 120, through the casing string, including through the wet shoe sub 110 and float equipment, and out the float shoe and into and up around the annulus between the casing string and the wellbore.

[0124] When the plug wiper 130 approaches the liner wiper 120 in the running tool, the plug wiper 130 lands within the liner wiper 120 and is secured within the liner wiper by the anti-release mechanism to form the dual wiper plug. The dual wiper plug is released from the running tool and travels downhole through the casing (or liner) of the downhole portion to the wet shoe sub 110. In some implementations, the dual wiper plug is released from the running tool when a predetermined pressure uphole of the dual wiper plug is exerted on shear pins securing the liner wiper 120 to the running tool. However, it is contemplated that the dual wiper plug can be released from the running tool using other known means.

[0125] In other implementations, such as a long-string application, the liner wiper 120 coupled with the plug wiper 130 ( / .e., the dual wiper plug in the pre-released configuration) is deployed from the surface using displacement fluid after the predetermined amount of cement slurry is pumped down the casing string. In such applications, the casing string is held at the surface with the cement being poured directly into the casing string. Thereforethere is no work string, running tool, or liner hanger (portion uphole of the liner wiper 120) for the plug wiper 130 to wipe and the dual plug deployed from the surface wipes the casing string only. The plug wiper 130 is prevented from releasing from the liner wiper 120 by the anti-release mechanism. The dual wiper plug travels downhole through the casing string and lands in the wet shoe sub 110.

[0126] The anti-release mechanism is configured to release when the dual wiper plug ( / .e., the plug wiper 130 landed in the liner wiper 120) lands in the wet shoe sub 110. Specifically, when the dual wiper plug lands in the downhole section 112c of the wet shoe collar 112, the catch ring 156 is sheared from the lock body 124 of the liner wiper 120 by the release shoulder 152, allowing the dual wiper plug to move downhole into the downhole section 112c of the wet shoe collar 112 while the catch ring 156 remains in the intermediate section 112b of the wet shoe collar 112. When the catch collar 154 is released from the catch ring 156, the catch collar 154 is configured to expand and pressure uphole from the plug wiper 130, such as from displacement fluid, pushes the plug wiper 130 into the plug catcher 116 in the extension sub 114. The plug wiper 130 is caught or retained within the plug catcher 116 and perforations 118 in the plug catcher 116 allow the displacement fluid uphole from the plug wiper 130 to flow through the downhole end of the liner wiper 120, through the perforations 118 in the plug catcher 116, into the sub extension 114 and out the outlet 110b of the wet shoe sub 110 at the downhole end of the sub extension 114 to clean the shoe track by displacing the desired volume of cement.

[0127] Several alternative implementations and examples have been described and illustrated herein. The implementations of the technology described above are intended to be exemplary only. A person of ordinary skill in the art would appreciate the features of the individual implementations, and the possible combinations and variations of the components. A person of ordinary skill in the art would further appreciate that any of the implementations could be provided in any combination with the other implementations disclosed herein. It is understood that the technology may be embodied in other specific forms without departing from the central characteristics thereof. The present implementations and examples, therefore, are to be considered in all respects as illustrative and not restrictive, and the technology is not to be limited to the details given herein. Accordingly, while the specific implementations have been illustrated and described, numerous modifications come to mind.

[0128] As used herein, “substantially”, “approximately”, and / or “about” means an acceptable variation according to conventional standards, otherwise at most a 5% to 10% variation from an indicated effect or value.

Claims

CLAIMS1 . A dual wiper plug comprising: a liner wiper having fluid communication between an uphole end and a downhole end, the liner wiper comprising: a wiper body coupled at a downhole end to a lock body; one or more liner wiper fins disposed around the wiper body; and an anti-release mechanism at the downhole end of the liner wiper; a plug wiper comprising a plug wiper body and a wiper nose configured to be received in the anti-release mechanism; wherein the anti-release mechanism is configured to secure the plug wiper in the liner wiper in a pre-release configuration and seal off the fluid communication through the downhole end of the liner wiper; and wherein the anti-release mechanism is configured to release the plug wiper from the liner wiper in a released configuration when the dual wiper plug lands in a subjacent structure to establish or re-establish the fluid communication through the downhole end of the liner wiper.

2. The dual wiper plug of claim 1 , wherein the anti-release mechanism comprises a catch collar and a catch ring releasably coupled to the lock body around the catch collar in the pre-release configuration, wherein the catch collar is configured to have a smaller inner diameter than the downhole end of the lock body in the pre-release configuration that is expandable in the released configuration when the catch ring is decoupled from the lock body.

3. The dual wiper plug of claim 2, wherein the catch collar is a retaining collet.

4. The dual wiper plug of claim 2, wherein the catch collar is at least one mechanical dog.

5. The dual wiper plug of any one of claims 2 to 4, wherein the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 200 psi.

6. The dual wiper plug of any one of claims 2 to 4, wherein the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 400 psi.

7. The dual wiper plug of any one of claims 2 to 6, wherein the catch ring is configured to decouple from the lock body when the catch ring is subjected to a predetermined pressure to shear value against a surface of the subjacent structure.

8. The dual wiper plug of claim 7, wherein the predetermined pressure to shear value is between about 1400 PSI and about 15000 PSI.

9. The dual wiper plug of claim 7, wherein the predetermined pressure to shear value is about 1750 PSI.

10. The dual wiper plug of claim 7, wherein the predetermined pressure to shear value is at least 5000 PSI.

11. The dual wiper plug of claim 7, wherein the predetermined pressure to shear value is at least 10000 PSI.

12. The dual wiper plug of any one of claims 7 to 11 , wherein the surface of the subjacent structure is a release shoulder configured to reduce an inner diameter of a downhole section of the subjacent structure to a value equal to or greater than an outer diameter of the lock body and less than an outer diameter of the catch ring, such that the catch ring is decoupled from the lock body upon contact with the release shoulder.

13. The dual wiper plug of any one of claims 1 to 12, wherein, when in the released configuration, the liner wiper defines a fluid path between the downhole end of the liner wiper and a downhole end of the subjacent structure.

14. The dual wiper plug of any one of claims 1 to 13, wherein the plug wiper body comprises one or more plug wiper fins disposed therearound.

15. The dual wiper plug of any one of claims 1 to 14, wherein an outer surface of the plug wiper comprises a first safe guard surface that is configured to engage with an inner surface of the liner wiper to prevent the plug wiper from flowing out the uphole end of the liner wiper.

16. The dual wiper plug of claim 15, wherein the first safe guard surface is a grooved plug wiper collar configured to engage with a first grooved surface on the inner surface of the liner wiper.

17. The dual wiper plug of any one of claims 1 to 16, wherein an outer surface of the liner wiper comprises a second safe guard surface that is configured to engage with an inner surface of the subjacent structure to prevent the liner wiper or the dual wiper plug from flowing out an uphole side of the subjacent structure.

18. The dual wiper plug of claim 17, wherein the second safe guard surface is a grooved liner wiper collar configured to engage with a second grooved surface on the inner surface of the subjacent structure.

19. The dual wiper plug of any one of claims 1 to 18, wherein the subjacent structure is a wet shoe sub.

20. A dual wiper plug comprising: a liner wiper having fluid communication between and through an uphole end and a downhole end, the liner wiper comprising: a wiper body; one or more liner wiper fins disposed around the wiper body; and a lock body having a catch collar at the downhole end of the liner wiper secured by a catch ring; a plug wiper comprising a plug wiper body and a wiper nose configured to be received in the catch collar;wherein the catch collar is configured to secure the plug wiper in the liner wiper and seal off the fluid communication through the downhole end of the liner wiper; and wherein the catch collar is configured to release the plug wiper upon the dual wiper plug landing in a subjacent structure to establish or re-establish the fluid communication through the downhole end of the liner wiper.

21. A dual wiper plug for use in establishing a wet shoe track, the dual wiper plug comprising a liner wiper having a hollow tubular body and a plug wiper configured to be retained in the hollow tubular body: wherein the liner wiper is configured to retain the plug wiper in the liner wiper in a pre-release configuration and wipe at least a downhole portion of the wellbore; and wherein the liner wiper is configured to release the plug wiper downhole in a released configuration when the dual wiper plug lands in a subjacent structure.

22. The dual wiper plug of claim 21 , wherein the plug wiper is configured to wipe an uphole portion of a wellbore and land in the liner wiper to plug the hollow tubular body.

23. The dual wiper plug of claim 21 or 22, wherein the liner wiper is configured to prevent the release of the plug wiper downhole until the dual wiper plug lands in the subjacent structure.

24. A wet shoe assembly comprising the dual wiper plug as defined in any one of claims 1 to 19 and a wet shoe sub comprising a wet shoe collar, an extension sub coupled to a downhole end of the wet shoe collar, and a plug catcher coupled to the downhole end of the wet shoe collar, wherein the subjacent structure is the wet shoe sub.

25. A wet shoe assembly comprising: a liner wiper having fluid communication between an uphole end and a downhole end, the liner wiper comprising a wiper body with one or more liner wiper fins disposed therearound and a lock body with a catch collar coupled to a downhole end of the lock body, wherein a catch ring retains the catch collar at a smaller inner diameter than an inner diameter of the lock body;a plug wiper comprising a plug wiper body and a wiper nose configured to be received in the catch collar; and a wet shoe sub comprising a wet shoe collar, an extension sub coupled to a downhole end of the wet shoe collar, and a plug catcher coupled to the downhole end of the wet shoe collar; wherein the catch collar is configured to secure the plug wiper in the liner wiper in a pre-release configuration and seal off the fluid communication at the downhole end of the liner wiper; and wherein the catch ring is configured to release the catch collar to release the plug wiper into the wet shoe sub in a released configuration when the dual wiper plug lands in the wet shoe sub to establish or re-establish the fluid communication at the downhole end of the liner wiper into the uphole end of the wet shoe sub.

26. The wet shoe assembly of claim 25, wherein the plug wiper body comprises one or more plug wiper fins disposed therearound.

27. The wet shoe assembly of claim 25 or 26, wherein the catch collar is configured to have a smaller inner diameter than the downhole end of the lock body in the prerelease configuration that is expandable in the released configuration when the catch ring is decoupled from the lock body.

28. The wet shoe assembly of any one of claims 25 to 27, wherein the catch collar is a retaining collet.

29. The wet shoe assembly of any one of claims 25 to 27, wherein the catch collar is at least one mechanical dog.

30. The wet shoe assembly of any one of claims 25 to 29, wherein the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 200 psi.

31. The wet shoe assembly of any one of claims 25 to 29, wherein the catch collar is configured to expand when a predetermined pressure uphole of the dual wiper plug exceeds about 400 psi.

32. The wet shoe assembly of any one of claims 25 to 31 , wherein the catch ring is configured to decouple from the lock body when the catch ring is subjected to a predetermined pressure to shear value against a surface of the wet shoe sub.

33. The wet shoe assembly of claim 32, wherein the predetermined pressure to shear value is between about 1400 PSI and about 2800 PSI.

34. The wet shoe assembly of claim 32, wherein the predetermined pressure to shear value is about 1750 PSI.

35. The wet shoe assembly of any one of claims 32 to 34, wherein the surface of the wet shoe sub is a release shoulder configured to reduce an inner diameter of a downhole section of the wet shoe sub to a value equal to or greater than an outer diameter of the lock body and less than an outer diameter of the catch ring, such that the catch ring is decoupled from the lock body upon contact with the release shoulder.

36. The wet shoe assembly of any one of claims 25 to 35, wherein, when in the released configuration, the liner wiper defines a fluid path between the downhole end of the liner wiper and a downhole end of the wet shoe sub.

37. A wet shoe assembly comprising: a dual wiper plug comprising a liner wiper comprising a body with one or more liner wiper fins disposed therearound and a catch collar; and a plug wiper nestable within the liner wiper; and a wet shoe sub comprising a sub body and a plug catcher disposed inside the sub body, wherein the catch collar is configured to secure the plug wiper in the liner wiper and seal off the fluid communication through the liner wiper; and wherein the catch collar is configured to release the plug wiper into the wet shoe sub upon the dual wiper plug landing in the wet shoe sub to establish or re-establish the fluid communication through the liner wiper and into the wet shoe sub.

38. The wet shoe assembly of claim 37, wherein the plug wiper comprises a plug wiper body having one or more plug wiper fins disposed therearound.

39. A method of cleaning a shoe track at a bottom of a tubular member in a wellbore, the method comprising: running a plug wiper through an uphole portion of the wellbore with a displacement fluid to displace a cement from the uphole portion; engaging the plug wiper in a liner wiper to form a dual wiper plug and running the dual wiper plug through a downhole portion of the wellbore to displace the cement from the downhole portion; landing the dual wiper plug in a wet shoe sub in the downhole portion; disengaging the plug wiper from the liner wiper such that the plug wiper flows into the wet shoe sub; and displacing the cement downhole of the wet shoe sub with the displacement fluid.

40. The method of claim 39, wherein the uphole portion includes a drill pipe, a drill string, a work string, and / or a running tool.

41. The method of claim 39 or 40, wherein the downhole portion is a casing or a liner.

42. The method of any one of claims 39 to 41 , wherein the plug wiper is a wiper dart.

43. The method of any one of claims 39 to 42, wherein the liner wiper comprises a wiper body coupled at a downhole end to a lock body; one or more liner wiper fins disposed around the wiper body; and an anti-release mechanism at the downhole end of the liner wiper, wherein the anti-release mechanism is configured to engage the plug wiper in the liner wiper in the downhole portion of the wellbore and disengage the plug wiper from the liner wiper when the dual wiper plug lands in the wet shoe sub.

44. The method of claim 43, wherein the anti-release mechanism comprises a catch collar and a catch ring releasably coupled to the lock body around the catch collar,wherein disengaging the plug wiper from the liner wiper comprises expanding the catch collar and releasing the catch ring from the lock body.

45. The method of claim 44, wherein expanding the catch collar occurs when a predetermined pressure uphole of the dual wiper plug is exceeded.

46. The method of claim 45, wherein the predetermined pressure uphold of the dual wiper plug is between about 200 psi and about 400 psi.

47. The method of any one of claims 44 to 46, wherein releasing the catch ring from the lock body occurs when a predetermined pressure to shear value against a surface of the wet shoe sub is exceeded.

48. The method of claim 47, wherein the predetermined pressure to shear value is one of: between about 1400 psi and about 15000 psi, is about 1750 psi, at least 5000 psi, or at least 10,000 psi.

49. The method of any one of claims 39 to 48, wherein engaging the plug wiper in the liner wiper to form the dual wiper plug further comprises an outer surface of the plug wiper engaging with an inner surface of the liner wiper.

50. The method of claim 49, wherein the outer surface of the plug wiper is a grooved plug wiper collar that engages with a first grooved surface on the inner surface of the liner wiper.

51. The method of any one of claims 39 to 50, wherein landing the dual wiper plug in the wet shoe sub further comprises engaging an outer surface of the liner wiper with an inner surface of the wet shoe sub.

52. The method of claim 51 , wherein the outer surface of the liner wiper comprises a grooved liner wiper collar configured to engage with a second grooved surface on the inner surface of the wet shoe sub.

53. A method of cleaning a shoe track at a bottom of a tubular member in a wellbore, the method comprising:running a dual wiper plug comprising a plug wiper disposed within a liner wiper through the wellbore with a displacement fluid to displace a cement from the wellbore; landing the dual wiper plug in a wet shoe sub in the wellbore; disengaging the plug wiper from the liner wiper such that the plug wiper flows into the wet shoe sub; and displacing the cement downhole of the wet shoe sub with the displacement fluid.

54. The method of claim 53, wherein the liner wiper comprises a wiper body coupled at a downhole end to a lock body; one or more liner wiper fins disposed around the wiper body; and an anti-release mechanism at the downhole end of the liner wiper, wherein the anti-release mechanism is configured to disengage the plug wiper from the liner wiper when the dual wiper plug lands in the wet shoe sub.

55. The method of claim 54, wherein the anti-release mechanism comprises a catch collar and a catch ring releasably coupled to the lock body around the catch collar, wherein disengaging the plug wiper from the liner wiper comprises expanding the catch collar and releasing the catch ring from the lock body.

56. The method of claim 55, wherein expanding the catch collar occurs when a predetermined pressure uphole of the dual wiper plug is exceeded.

57. The method of claim 56, wherein the predetermined pressure uphold of the dual wiper plug is between about 200 psi and about 400 psi.

58. The method of any one of claims 55 to 57, wherein releasing the catch ring from the lock body occurs when a predetermined pressure to shear value against a surface of the wet shoe sub is exceeded.

59. The method of claim 58, wherein the predetermined pressure to shear value is one of: between about 1400 psi and about 15000 psi, is about 1750 psi, at least 5000 psi, or at least 10,000 psi.

60. The method of any one of claims 53 to 59, further comprising engaging the plug wiper in the liner wiper to prevent the plug wiper from flowing uphole.

61. The method of claim 60, wherein engaging the plug wiper in the liner wiper comprises an outer surface of the plug wiper engaging with an inner surface of the liner wiper.

62. The method of claim 61 , wherein the outer surface of the plug wiper is a grooved plug wiper collar that engages with a first grooved surface on the inner surface of the liner wiper.

63. The method of any one of claims 53 to 62, wherein landing the dual wiper plug in the wet shoe sub further comprises engaging an outer surface of the liner wiper with an inner surface of the wet shoe sub.

64. The method of claim 63, wherein the outer surface of the liner wiper comprises a grooved liner wiper collar configured to engage with a second grooved surface on the inner surface of the wet shoe sub.

65. The method of any one of claims 39 to 43, wherein the dual wiper plug and / or wet shoe assembly has one or more features as defined in any one of claims 1 to 38 and / or as described or illustrated herein.

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