Methods and kits for assembling a flow cage assembly for downhole reciprocating pump

Methods and kits for assembling a flow cage assembly are provided. The flow cage assembly may be used in a traveling valve or a standing valve of a downhole pump. In some embodiments, the kit comprises a tubular body having an axial bore, a tubular insert, and a retaining element. The kit may be assembled such that the retaining element forms an interference fit with the tubular body and thereby retains the tubular insert within the axial bore. In some embodiments, the interference fit between the retaining element and the tubular body may reduce or eliminate a possible failure point within the flow cage assembly.

TECHNICAL FIELD

The present disclosure relates to artificial lift systems such as reciprocating downhole pumps. More particularly, the present disclosure relates to methods and kits for assembling flow cage assemblies for a downhole reciprocating pump.

BACKGROUND

In hydrocarbon recovery operations, an artificial lift system is typically used to recover fluids from a well in a subterranean earth formation. Common artificial lift systems include reciprocating pumps such as sucker rod pumps. The pump may generally comprise a plunger disposed within a barrel and a valve system. The plunger is moved up and down within the barrel in order to draw fluids to the surface. More particularly, the plunger may be coupled to a lower end of a reciprocating rod or rod string, for example. The rod string may be referred to as a “sucker rod.”

The valve system may include a standing valve and a travelling valve. The standing valve may be positioned at the bottom of the barrel, and the travelling valve may be coupled to a bottom end of the plunger. On the downstroke, pressure differentials may close the standing valve and open the travelling valve. Fluids in the barrel may thereby pass upward through the travelling valve and plunger during the downstroke. On the upstroke, reversed pressure differentials may close the travelling valve and open the standing valve. Fluids above the travelling valve maybe moved upward by motion of the plunger, and fluids from the earth formation or reservoir may enter the barrel (below the plunger) via the standing valve.

The standing valve and the travelling valve may each be a respective ball check valve. A ball check valve may comprise a ball in a flow cage assembly that can move between a first position in which flow is blocked and a second position in which fluid may flow through the cage. Typically, in a flow blocking position, the valve ball sits on a ball seat (such as a ring) and blocks fluid flow through an opening in the ball seat.

For improved durability in the downhole environment, some flow cage assemblies comprise an external tubular body or “shell” assembled with an internal insert. The insert, which is repeatedly impacted by the ball during use, can be made of a hard, durable material such as cobalt or another suitable material. The body can be made of a material having greater tensile strength such as steel, as it experiences greater axial compression and tensile forces due to reciprocation of the rod string. The flow cage assembly may also comprise a ball seat made of the same material as the insert.

Examples of conventional insert-type flow cage assemblies are shown inFIGS.1A and1B.

FIG.1Ais a side, partial cross-sectional view of an example conventional flow cage assembly10configured for a standing valve. The flow cage assembly10is shown assembled with a top bushing20. The top bushing20is configured to connect at its uphole end to the downhole end of a barrel (not shown). The flow cage assembly10comprises a body12, an insert14, a ball seat16, and a sealing member18. The insert14is configured to receive a valve ball (not shown) therein.

The sealing member18forms a seal between the insert14and the top bushing20to prevent leaks at the threaded connection between the flow cage assembly10and the top bushing20. However, the repeated axial and lateral movement of the valve ball within the insert14can cause wear to the sealing member18. As the sealing member18is typically made of rubber or another relatively soft material, it presents a potential failure point at which leaks may still occur. In addition, the threaded connection decreases the thickness of the wall of the body12, providing another weak point vulnerable to cracking and fatigue.

FIG.1Bis a side, partial cross-sectional view of an example flow cage assembly30configured for a traveling valve. The flow cage assembly30is shown assembled with a top bushing40. The top bushing40is configured to connect at its uphole end to the downhole end of a plunger (not shown). Similar to the flow cage assembly10ofFIG.1A, the flow cage assembly30comprises a body32, an insert34, a ball seat36, and a sealing member38. The sealing member38forms a seal between the insert34and the top bushing40. The sealing member38presents a potential failure point in a similar manner to the sealing member18of the flow cage assembly10as discussed above.

An alternative flow cage design comprises a screw-in ball seat bushing configured to threadingly couple with internal threads formed in the inner wall of the body. However, fluid leaks between the threads of the seat and the body can result in erosive wear of the threads, which in turn can result in loosening of the connection between the seat and body.

Another alternative flow cage design is described in U.S. Pat. No. 6,029,685 in which a top bushing is friction welded to the body to retain the insert therein. Such a cage design eliminates the potential leak point between the body and the top bushing, negating the need for a sealing member therebetween. However, the friction weld joining the body and top bushing presents a potential weak point, as the material around the weld may be weakened, for example due to embrittling of the surrounding material, porosities created by the weld, and the like.

SUMMARY

In one aspect, there is provided a method for assembling a flow cage assembly, the method comprising: providing a tubular body having an axial bore, the axial bore having a first diameter, wherein the axial bore is expandable to a second diameter when the tubular body is heated; providing a tubular insert, the tubular insert receivable into the axial bore; providing a retaining element, the retaining element receivable into the axial bore and having an outer diameter between the first and second diameters; heating the tubular body such that the axial bore expands to the second diameter; inserting the tubular insert into the axial bore; inserting the retaining element into the axial bore such that the retaining element abuts the tubular insert; and cooling the tubular body such that the tubular body and the retaining element form an interference fit.

In some embodiments, the retaining element comprises an annular portion and a plug portion.

In some embodiments, the plug portion is integral with the annular portion, the annular portion abutting the tubular insert.

In some embodiments, the plug portion is separate from the annular portion, and wherein inserting the retaining element into the axial bore comprises inserting the annular portion and inserting the plug portion such that the plug portion abuts the annular portion.

In some embodiments, the method further comprises using the plug portion to manipulate the positioning of the retaining element in the axial bore.

In some embodiments, the method further comprises removing the plug portion after the interference fit has been formed such that only the annular portion remains.

In some embodiments, removing the plug portion comprises machining the plug portion out of the axial bore.

In some embodiments, the tubular body is heated to a temperature of between about 500° F. and about 900° F.

In some embodiments, the tubular body is heated for about 3 to about 10 minutes.

In some embodiments, the tubular body has an uphole end and a downhole end, and the uphole end faces downward while the tubular insert and the retaining element are inserted and the interference fit is formed.

In some embodiments, the tubular body comprises an annular shoulder extending radially into the axial bore; and inserting the tubular insert into the axial bore comprises inserting the insert to abut the annular shoulder.

In some embodiments, the method further comprises forming an upper connector portion and a lower connector portion in the tubular body.

In some embodiments, the retaining element and the tubular body are comprised of the same material.

In some embodiments, the retaining element and the tubular body are each comprised of alloy steel, monel, or stainless steel.

In another aspect, there is provided a flow cage assembly produced by embodiments of the method described herein.

In another aspect, there is provided a kit for assembling a flow cage assembly, comprising: a tubular body having an axial bore therethrough, the axial bore having a first diameter, wherein the axial bore is expandable to a second diameter when the tubular body is heated; a tubular insert receivable into the axial bore of the tubular body; and a retaining element having an outer diameter between the first diameter and the second diameter, the retaining element comprising an annular portion and a plug portion.

In some embodiments, the plug portion is integral with the annular portion.

In some embodiments, the plug portion is separate from the annular portion.

In some embodiments, the retaining element and the tubular body are comprised of the same material.

In some embodiments, the retaining element and the tubular body are each comprised of alloy steel, monel, or stainless steel.

Other aspects and features of the present disclosure will become apparent, to those ordinarily skilled in the art, upon review of the following description of specific embodiments of the disclosure.

DETAILED DESCRIPTION

Generally, the present disclosure provides a method for assembling a flow cage assembly. The flow cage assembly may be used to assemble a traveling valve or a standing valve. A related kit is also provided herein. The kit may comprise a tubular body having an axial bore, a tubular insert, and a retaining element. The kit may be assembled such that the retaining element forms an interference fit with the tubular body and thereby retains the tubular insert within the axial bore.

As used herein and in the appended claims, the singular forms of “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise.

In this disclosure, the “uphole” direction refers to the direction toward the surface in a well or borehole. The “downhole” direction refers to the direction toward the bottom of the well or borehole (i.e. opposite to the uphole direction). The terms “upward” and “downward” may be used to refer to the “uphole” and “downhole” directions, respectively, unless the context dictates otherwise.

The term “downhole pump” refers to any pumping system positioned within a well or borehole for pumping fluids or other materials to the surface. The term “reciprocating downhole pump” refers to any pump system in which one or more components reciprocates within the well for moving fluids or other materials uphole, such as downhole pump comprising a reciprocating plunger in a barrel.

The term “standing valve” refers to a valve positioned at or near the bottom of the barrel or corresponding structure of the downhole pump. The term “traveling valve” refers to a valve that travels with the plunger or other reciprocating component of the downhole pump.

The term “insert-type flow cage assembly” refers to a flow cage comprising an outer tubular body or “shell” and an inner tubular insert configured to receive a valve ball therein.

An example kit100for assembling a flow cage assembly will be described with reference toFIGS.2A to5B(the complete kit100is visible inFIGS.5A and5B). The kit100may be used to implement embodiments of the methods described herein.

The kit100in this embodiment comprises a tubular insert202(shown inFIGS.2A-2B), a tubular body or shell302(shown inFIGS.3A-3C) and a retaining element402(shown inFIGS.4A-4C).

Referring toFIGS.2A and2B, the insert202in this embodiment comprises a generally tubular body206and has an uphole end203and a downhole end205. The uphole end203is an outlet end and the downhole end205is an inlet end. The body206defines an axial flow passage216therethrough from the uphole end203to the downhole end205.

As shown inFIG.2B, the body206of the insert202has an outer diameter D1and the axial flow passage216has a diameter D2at the downhole end205of the insert202. The diameter D2is a suitable diameter to receive a valve ball (not shown) into the axial flow passage216. The diameter D1is a suitable diameter such that the insert202may be received into the tubular body302, as described in more detail below.

The body206of the insert202comprises an upper ring204and a lower ring208with a plurality of circumferentially spaced ribs210therebetween. The ribs210define a plurality of side openings212. In this embodiment, the ribs210are angled such that each of the side openings212extends along a substantially helical path. Thus, incoming fluid is induced to adopt a helical flow pattern as it moves through the insert202, thereby creating a centrifugal effect. In other embodiments, the ribs may be relatively straight and thereby define substantially vertical side openings, similar to the inserts14and34ofFIGS.1A and1B, respectively.

As shown inFIG.2B, the body206further comprises a central ball stop214that extends upwards past the upper ring204. The side openings212extend through the upper ring204to form outlet openings218disposed circumferentially around the ball stop214.

In some embodiments, the insert202is comprised of a relatively hard and durable material. In some embodiments, the insert202is comprised of cobalt. In other embodiments, the insert202is comprised of any other suitable material.

Referring toFIGS.3A to3C, the tubular body or shell302in this embodiment is approximately cylindrical in shape and has an uphole end303and a downhole end305. The uphole end303is an outlet end and the downhole end305is an inlet end. The tubular body302has an inner wall304and an outer wall306. The inner wall304defines an axial bore308extending through the tubular body302from the uphole end303to the downhole end305(the axial bore308is visible inFIGS.3A and3C).

As shown inFIG.3C, the inner wall304of the tubular body302defines an annular shoulder310extending radially inward into the axial bore308. The axial bore308comprises a first upper section312and a second upper section313uphole of the annular shoulder310. The axial bore308further comprises a first lower section314and a second lower section315downhole of the annular shoulder310.

The first upper section312has a diameter D3. The diameter D3of the first upper section312may be selected to allow the tubular body302to engage a suitable uphole component of a plunger or barrel of a downhole pump. In this embodiment, the second upper section313is tapered from the first upper section312toward the annular shoulder310such that its diameter increases from diameter D3to its widest diameter D3′ proximate the annular shoulder310. The tapering of the second upper section313may provide a gradual transition of fluid flowing uphole from the first lower section314to the first upper section312. In other embodiments, the second upper section313is not tapered and its diameter is approximately the same as the diameter D3of the first upper section312.

The first lower section314has a diameter D4and the second lower section315has a diameter D5. The diameter D4is a suitable diameter such that the tubular insert202may be received into the first lower section314of the axial bore308. In some embodiments, the diameter D4is approximately the same as the outer diameter D1of the insert202such that the insert202fits snugly into the first lower section314. The diameter D5of the second lower section315may be slightly greater than the diameter D4. In some embodiments, the diameter D5is the same or similar to the outer diameter D6of the retaining element402as described in more detail below.

In this embodiment, the diameter D4of the first lower section314is greater than the diameter D3of the first upper section312, with the tapered second upper section313providing a gradual transition therebetween. The differences in the diameter of the inner wall304at the first lower section314and the second upper section313thereby forms the annular shoulder310therebetween. In other embodiments, the annular shoulder310comprises an annular protrusion extending from the inner wall304of the body302. In these embodiments, the diameter D3may be approximately the same as the diameter D4.

In some embodiments, the tubular body302is comprised of a material with relatively high tensile strength. In some embodiments, the tubular body302is comprised of alloy steel, monel, or stainless steel. In other embodiments, the tubular body302comprises any other suitable material.

Referring toFIGS.4A to4C, the retaining element402in this embodiment is generally cylindrical in shape and has an uphole end403and a downhole end405.

The retaining element402comprises a plug portion412proximate the uphole end403and an annular portion410proximate the downhole end405. In this embodiment, the plug portion412is integral with the annular portion410. In other embodiments, the plug portion412is separate from the annular portion410. In yet other embodiments, the plug portion412is omitted and the retaining element402only comprises the annular portion410.

In this embodiment, the plug portion412is substantially solid. Alternatively, the plug portion412may be tubular with an axial bore extending all or partially therethrough (not shown).

As shown inFIG.4C, the retaining element402comprises an outer wall406that extends the length of the retaining element402and an inner wall404that extends the length of the annular portion410. The inner wall404defines an opening408in the annular portion410at the downhole end405.

The retaining element402has an outer diameter D6defined by the outer wall406and the annular portion410has an inner diameter D7defined by the inner wall404. The outer diameter D6may be slightly greater than the diameter D4of the first lower section314of the axial bore308of the tubular body302. In some embodiments, the outer diameter D6is approximately equal to the diameter D5of the second lower section315. The difference between the outer diameter D6and the D4of the first lower section314allows the annular portion410of the retaining element402to form an interference fit with the tubular body302, as described in more detail below. In some embodiments, the interference is between about 0.001 to about 0.0025 inches per inch of diameter. The allowance per inch may decrease as the diameter D4of the axial bore increases. For the range of valve cage sizes for pump bores, which are typically about 1 inch to about 6 inches in diameter, the interference may be between about 0.001 to about 0.013 inches. However, a person skilled in the art would understand that the design interference may be lower or higher than this range.

The inner diameter D7of the annular portion410is at least the diameter of the valve ball (not shown) to allow the valve ball to be inserted through the opening408and into the axial flow passage216of the insert202. In some embodiments, the inner diameter D7is approximately equal to the diameter D2of the axial flow passage216(at downhole end205) of the insert202.

In some embodiments, the retaining element402is comprised of the same material as the tubular body302. In some embodiments, the retaining element402is comprised of alloy steel, monel, or stainless steel. In other embodiments, the retaining element402is comprised of any other suitable material.

FIGS.5A and5Bare exploded side and perspective views, respectively, of the kit100including the insert202, the tubular body302, and the retaining element402.FIGS.5A and5Bshow the kit100in an orientation ready for assembly, with the insert202, the tubular body302, and the retaining element402axially aligned and their respective uphole ends203,303, and403facing in the same direction. The assembly of the kit100will be discussed in more detail below.

FIG.6Ais a flowchart of an example method600for assembling a flow cage assembly, according to some embodiments. The method600may be implemented using the kit100.

At block602, a tubular body is provided. As used herein, “providing” in this context refers to making, buying, acquiring, or otherwise obtaining one of the components described herein. The tubular body comprises an axial bore having a first diameter. In this example, the tubular body is the tubular body302having the axial bore308as described above. The first diameter is the diameter D4of the first lower section314of the axial bore308. The first lower section314of the axial bore308is expandable to a second diameter (not shown) when the tubular body302is heated, as described in more detail at block608below.

At block604, an insert is provided, the insert receivable into the axial bore of the tubular body. The insert comprises an axial flow passage to receive a valve ball therein. In this example, the insert is the insert202with the axial flow passage216, as described above.

At block606, a retaining element is provided, the retaining element having an outer diameter that is between the first diameter and the second diameter of the axial bore. The retaining element in this example is the retaining element402having outer diameter D6. In this embodiment, the retaining element402and the tubular body302are made of the same material such as, for example, alloy steel, monel, or stainless steel.

At block608, the tubular body302is heated to expand the axial bore308to the second diameter. In some embodiments, the tubular body302is heated to expand the axial bore308such that the second diameter is at least about 0.001 to 0.0025 inches (per inch of diameter) greater than the first diameter D4. For the range of valve cage sizes for pump bores from about 1 to 6 inches, the second diameter may be at least about 0.001 to 0.013 inches greater than the first diameter D4. In other embodiments, the second diameter may be any suitable other diameter greater than the first diameter D4.

The tubular body302may be heated by any suitable heating mechanism. In some embodiments, the tubular body302is heated by placing the tubular body302in an oven at the desired temperature. The temperature and heating time may be selected based on the size and geometry (e.g. diameter) of the tubular body302as well as the material it comprises and the coefficient of thermal expansion of that material. The temperature and heating time may be limited to prevent unintended tempering of a given material, which is specific to the alloy and metallurgical conditions of the materials used. In some embodiments, the tubular body302is heated to a temperature between about 500° F. (about 260° C.) to about 900° F. (approximately 482° C.). In some embodiments, the tubular body302is heated to approximately 900° F. (approximately 482° C.). In some embodiments, the tubular body302is heated for about 3 minutes to about 10 minutes. In some embodiments, the tubular body302is heated for about 5 minutes to about 7 minutes. In other embodiments, a suitable temperature and heating time may be determined by one skilled in the art based on known formulas, published material properties, and/or empirical trials. Embodiments are not limited to the specific temperatures and times disclosed herein.

The tubular body302is then removed from the oven for use at block610. In some embodiments, the steps at block610are performed almost immediately after the steps of block608, or within a few minutes, to avoid significant cooling of the tubular body302until block614described below.

At block610, the tubular insert202is inserted into the axial bore308of the tubular body302. The tubular insert202may be at room temperature prior to insertion into the tubular body302. As used herein, “room temperature” or “ambient temperature” refers to a temperature of a temperature-controlled building or environment. For example, room temperature may be between about 15° C. and about 30° C. or between about 19° C. and about 25° C.

In some embodiments, the tubular body302is positioned with its uphole end303facing downwards and the insert202is inserted into the tubular body302with its own uphole end203facing downwards (i.e. opposite to how the tubular body302and the insert202would be positioned in a downhole pump). The insert202may be inserted such that the upper ring204abuts the annular shoulder310of the tubular body302.

At block612, the retaining element402is inserted into the axial bore308of the tubular body302. In some embodiments, the retaining element402is at room temperature prior to insertion into the tubular body302. In other embodiments, the retaining element402is cooled prior to insertion. For example, the retaining element402may be cooled a few degrees by placing the retaining element402in cooling device, such as a refrigerator or freezer, for a suitable period of time. Alternatively, the retaining element402may be cooled using dry ice, liquid nitrogen, or the like.

The retaining element402may be inserted into the tubular body302with its uphole end403facing downwards. The retaining element402may be inserted such that the retaining element402abuts the tubular insert202. More particularly, the retaining element402may be inserted such that the annular portion410abuts the downhole end205of the insert202. The opening408may therefore be approximately axially aligned with the axial flow passage216at the downhole end205of the insert202. When the retaining element402is inserted into the axial bore308, the annular portion410is received into the first lower section314and the plug portion412is received into the second lower section315of the axial bore308. In this embodiment, the plug portion412is integral with the annular portion410. In other embodiments, the plug portion412is separate from the annular portion410and the annular portion410is inserted into the axial bore308first, followed by insertion of the plug portion412.

In some embodiments, the plug portion412of the retaining element402is longer than the second lower section315of the axial bore308. The plug portion412may thereby extend longitudinally beyond the downhole end305of the tubular body302when the retaining element402is received in the axial bore308(as shown inFIGS.7A and7B, discussed below). The plug portion412may thereby be used to manipulate the retaining element402to position the retaining element402in the axial bore308of the tubular body302. For example, an operator may grip the plug portion412by hand or with a pair of tongs to position the retaining element402. The retaining element402may be positioned such that the annular portion410abuts the insert202and the opening408is axially aligned with the axial flow passage216. The weight of the plug portion412may help to maintain the positioning of the retaining element402and the insert202by pressing the annular portion410against the insert202and the insert202against the annular shoulder310of the tubular body302.

In this embodiment, the retaining element402is inserted to directly abut the insert202. However, in other embodiments, a ball seat (such as ball seat1104or1204shown inFIGS.11and12) is inserted following insertion of the insert202at block610and then the retaining element402is inserted to abut the ball seat. In these embodiments, the retaining element402retains both the insert202and the ball seat in the axial bore308.

At block614, the tubular body302is cooled such that the tubular body302and the retaining element402form an interference fit. In some embodiments, the tubular body302is cooled by allowing the tubular body302to sit at room temperature. In other embodiments, the tubular body302is cooled in a cooling device including, for example, a refrigerator or freezer. Alternatively, the tubular body302may be cooled using dry ice, liquid nitrogen, or the like.

In this embodiment, only the annular portion410of the retaining element402forms an interference fit with the tubular body302whereas the plug portion412does not. In other embodiments, the entire retaining element402forms an interference fit with the tubular body302. The retaining element402thereby securely retains the insert202in the axial bore308of the tubular body302.

FIGS.7A and7Bshow the kit100assembled by the method600ofFIG.6A.

As shown inFIG.7B, when the kit100is assembled, the insert202is received into the first lower section314of the axial bore308of the tubular body302such that the upper ring204abuts the annular shoulder310. The ball stop214of the insert202extends into the second upper section313of the axial bore308.

The retaining element402is received into the axial bore308such that the annular portion410abuts the downhole end205of the insert202. The opening408of the retaining element402is thereby approximately aligned with the axial flow passage216of the insert202. When the retaining element402is inserted into the axial bore308, the annular portion410is received into the first lower section314and the plug portion412is received into the second lower section315of the axial bore308. In this embodiment, the plug portion412of the retaining element402is longer than the second lower section315of the axial bore and thus extends longitudinally beyond the downhole end305of the tubular body302. This configuration may facilitate the positioning of the retaining element402in the axial bore308as discussed above.

In this embodiment, the annular portion410of the retaining element402forms an interference fit with the tubular body302due to the difference between the outer diameter D6of the retaining element402and the diameter D4of the first lower section314of the axial bore308. In this embodiment, the plug portion412does not form an interference fit with the tubular body302due to the slightly greater diameter D5of the second lower section315compared to the diameter D4of the first lower section324. Thus, the plug portion412may be easily removed, as described in more detail below. However, as the diameter D5is only slightly greater than the diameter D4, the axial alignment of the annular portion410and the insert202is not lost while the interference fit is being formed.

When the interference fit is formed between the annular portion410of the retaining element402and the tubular body302, the outer wall406of the annular portion410is substantially sealed against the inner wall304of the tubular body302and the annular portion410cannot be slidably moved or rotated within the axial bore308. The annular portion410thereby secures the insert202within the axial bore308between the annular portion410and the annular shoulder310of the tubular body302.

Therefore, in some embodiments, the interference fit between the annular portion410and the tubular body302eliminates the need for a sealing member to retain the insert202within the tubular body302and may thereby reduce or eliminate a possible failure point.

FIG.6Bis a flowchart showing additional steps to the method600ofFIG.6A.

At block616, the plug portion412of the retaining element402is removed. With the plug portion412removed, only the annular portion410remains and the opening408extends fully through the annular portion410.

In this embodiment, the plug portion412is integral with the annular portion410and the plug portion412is removed by machining the plug portion412out of the second lower section315of the axial bore308of the tubular body302. As used herein, “machining” refers to use of a machine to selectively remove material from a body. The plug portion412may be machined using a chucking machine, a drilling machine, a grinding machine, a broaching machine, or any other suitable type of machine. It will be understood that “removing” the plug portion412refers to removing substantially the entire plug portion412, although it is possible that traces may still remain after machining.

In other embodiments, where the plug portion412is a separate component from the annular portion410, the plug portion412may be removed by sliding the plug portion412out of the axial bore308. For example, the plug portion412may be slid out of the axial bore308by hand or using a pair of tongs.

In other embodiments, where the retaining element402only comprises an annular portion410, and not the plug portion412, the steps at block616may be omitted.

At block618, a lower connector portion is formed in the tubular body302. The lower connector portion may be proximate the downhole end305of the tubular body302. The lower connector portion may be configured to engage a seat bushing, a plug seat, or any other suitable component of a downhole pump that may be positioned downhole of the tubular body302.

In some embodiments, the lower connector portion is formed in the inner wall304or outer wall306of the tubular body302. The lower connector portion may be formed by machining or any other suitable method. In some embodiments, the lower connector portion comprises a threaded section that threadingly engages a complementary threaded section in seat bushing, plug seat, or other component. In other embodiments, the lower connector portion comprises any other suitable structure to facilitate connection to another component of a downhole pump and embodiments are not limited to threaded connections.

At block620, an upper connector portion is formed in the tubular body302. The upper connector portion may be proximate the uphole end303of the tubular body302. The upper connector portion may be configured to engage a barrel, a plunger, or any other suitable component of a downhole pump that may be positioned uphole of the tubular body302.

In some embodiments, the upper connector portion is formed in the inner wall304or the outer wall306of the tubular body302. The upper connector portion may be formed by machining or any other suitable method. In some embodiments, the upper connector portion comprises a threaded section that threadingly engages a complementary threaded section in the barrel, plunger, bushing, or other component. In other embodiments, the upper connector portion comprises any other suitable structure to facilitate connection to another downhole component of a downhole pump and embodiments are not limited to threaded connections.

InFIG.6B, block618is shown before block620; however, in other embodiments, the steps of block620can be performed before the steps of block618or at substantially the same time. In alternative embodiments, the upper connector portion may be formed before the plug portion412is removed at block616. In other embodiments, the tubular body302may be provided at block604with the upper connector portion already formed therein.

Therefore, by removing the plug portion412from the axial bore308and forming upper and lower connector portions in the tubular body302, the tubular body302can be adapted for use as part of a standing valve assembly (e.g. where the upper connector portion is configured to connect with a barrel and the lower connector portion is configured to connect with a seat bushing) or as part of a traveling valve assembly (e.g. where the upper connector portion is configured to connect to a plunger and the lower connector portion is configured to connect with a seat plug) as desired.

FIGS.8A to8Care cross-sectional views of an example flow cage assembly800assembled from the kit100using the method600, shown at various stages of the steps of blocks616-620described above (the final flow cage assembly800is shown inFIG.8C). In this embodiment, the flow cage assembly800is configured for use in a traveling valve assembly of a downhole pump.

As shown inFIG.8A, the plug portion412of the retaining element402has been removed and only the annular portion410remains (the plug portion412is therefore not visible inFIGS.8A-8C). The remaining annular portion410secures the insert202in the axial bore308of the tubular body302.

As shown inFIG.8B, a lower connector portion804may be formed in the tubular body302proximate the downhole end305. The lower connector portion804in this embodiment is configured to engage a seat plug (such as the seat plug1108shown inFIG.11, discussed below). In some embodiments, forming the lower connector portion804comprises forming a threaded section in the inner wall304of the tubular body302at the location indicated by dashed lines805. It will be understood that although dashed lines805are shown on either side of the inner wall304, the threaded section will extend around the full circumference of the inner wall304.

As shown inFIG.8C, an upper connector portion802may be formed in the tubular body302proximate the uphole end303. In this embodiment, the upper connector portion802is configured to engage a downhole end of a plunger (such as the plunger1106shown inFIG.11, discussed below). In some embodiments, forming the upper connector portion802comprises machining the inner wall304to widen the first upper section312of the axial bore308to produce a first widened section812. In some embodiments, the inner wall304at the second upper section313of the axial bore308may also be machined to produce a second widened section813.

In this embodiment, forming the upper connector portion802further comprises forming a threaded section in the inner wall304of the tubular body302at the location indicated by dashed lines803. The threaded section may be disposed around the circumference of the first widened section812of the axial bore308. It will be understood that although dashed lines803are shown on either side of the inner wall304, the threaded section will extend around the full circumference of the inner wall304. When the upper and lower connector portions802and804have been formed in the tubular body302, the flow cage assembly800is ready for use in a traveling valve assembly.

FIGS.9A and9Bshow another example flow cage assembly900assembled from the kit100using the method600. The flow cage assembly900is configured for use in a standing valve assembly of a downhole pump.

As shown inFIG.9B, the plug portion412of the retaining element402has been removed such that only the annular portion410remains (the plug portion412is therefore not visible inFIG.9B). The annular portion410secures the insert202in the axial bore308of the tubular body302.

A lower connector portion904has been formed in the tubular body302proximate the downhole end305. In this embodiment, the lower connector portion904has been formed in the inner wall304of the tubular body302and is configured to engage a seat bushing (such as the seat bushing1208shown inFIG.12, discussed below). In some embodiments, the lower connector portion904comprises a threaded section (such as threaded section908visible inFIG.12).

An upper connector portion902has been formed in the tubular body302proximate the uphole end303. In this embodiment, the upper connector portion902has been formed in the outer wall306of the tubular body302and is configured to engage a downhole end of a barrel (such as barrel1206ofFIG.12). In this embodiment, the outer wall306of the tubular body302has been machined proximate the uphole end303to produce a narrowed portion903. The narrowed portion903may be configured to be received into the downhole end of the barrel. In some embodiments, the narrowed portion903comprises a threaded section (such as threaded section906visible inFIG.12).

Therefore, in some embodiments, the same kit100can be used to assemble a flow cage assembly for either a standing valve or a traveling valve, depending on the upper and lower connector portions formed in the tubular body. In other embodiments, the kit may comprise a tubular body, insert, and retaining element of a particular size suitable for a specific standing valve or traveling valve.

FIG.10is a flowchart of an example method1000for assembling a valve assembly, according to some embodiments. The method1000may be used to assemble a traveling valve assembly or a standing valve assembly.

At block1002, a flow cage assembly is provided. In this example, the flow cage assembly is the flow cage assembly800or900as described above. The flow cage assembly800/900may comprise a tubular body302and an insert202secured with a retaining element402.

At block1004, a valve ball is inserted into the flow cage assembly800/900. The valve ball may be inserted through the opening408of the retaining element402into the axial flow passage216of the insert202.

At block1006, a ball seat is inserted into the flow cage assembly800/900. The ball seat may be inserted into the axial bore308of the tubular body302, below the valve ball, such that the ball seat abuts the retaining element402. The ball seat thereby forms a lower boundary for the valve ball, while the ball stop214of the insert202forms an upper boundary. The ball seat may be approximately ring-shaped with a central hole or opening therethrough. In some embodiments, the ball seat is made of the same material as the insert202. In other embodiments, the ball seat is made of any other suitable material.

In some embodiments, the method1000further comprises connecting the flow cage assembly800/900to an uphole component and a downhole component. The flow cage assembly800/900may be connected to an uphole component via the upper connector portion802/902and connected to a downhole component via the lower connector portion804/904. In some embodiments, where the valve assembly is a traveling valve assembly, the uphole component comprises a plunger and the downhole component comprises a seat plug. In other embodiments, where the valve assembly is a standing valve assembly, the uphole component comprises a barrel and the downhole component comprises a seat bushing. In other embodiments, the uphole and downhole components are any other suitable components.

FIG.11is a cross-sectional view of an example traveling valve assembly1100including the flow cage assembly800ofFIG.8C, assembled using the method1000ofFIG.10. The traveling valve assembly1100is shown assembled with a plunger1106(note that only a portion of the plunger1106is shown inFIG.11) and a seat plug1108.

The traveling valve assembly1100comprises the flow cage assembly800, a valve ball1102, and a ball seat1104. The valve ball1102is received in the axial flow passage216of the insert202and the ball seat1104is received in the axial bore308of the tubular body302. The ball seat1104in this embodiment is ring-shaped with a central opening1105therethrough. The ball seat1104abuts the annular portion410of the retaining element402.

The seat plug1108in this embodiment is generally tubular in shape with an axial channel1107therethrough. The seat plug1108is partially received into axial bore308of the tubular body302and abuts the ball seat1104. The seat plug1108comprises an upper connector portion1114that engages the lower connector portion804of the tubular body302. In this embodiment, the lower connector portion804of the tubular body302comprises an inner threaded section808and the upper connector portion1114of the seat plug1108comprises a complementary outer threaded section1118such that the tubular body302threadingly engages the seat plug1108. The seat plug1108thereby secures the ball seat1104in the axial bore308against the retaining element402.

The plunger1106comprises a lower connector portion1112that is received into the first widened section812of the axial bore308. In this embodiment, the upper connector portion802of the tubular body302comprises an inner threaded section806and the lower connector portion1112of the plunger1106comprises an outer threaded section1116such that the tubular body302threadingly engages the plunger1106.

In use, on the upstroke, the valve ball1102is seated on the ball seat1104such that the traveling valve1100is closed and the valve ball1102blocks fluid flow in the downhole direction. On the downstroke, the valve ball1102is raised from the ball seat1104such that the traveling valve1100is open, allowing upward flow of fluid through the axial flow passage of the insert202(via the axial channel1107of the seat plug1108and the central opening1105of the ball seat1104) and into the plunger1106.

FIG.12is a cross-sectional view of an example standing valve assembly1200including the flow cage assembly900ofFIGS.9A and9B, assembled using the method1000ofFIG.10. The standing valve assembly1200is shown assembled with a barrel1206(only a portion of the barrel1206is shown inFIG.12) and a seat bushing1208.

The standing valve assembly1200comprises the flow cage assembly900, a valve ball1202, and a ball seat1204. The valve ball1202is received in the axial flow passage216of the insert202and the ball seat1204is received in the axial bore308of the tubular body302. The ball seat1204in this embodiment is ring-shaped with a central opening1205therethrough. The ball seat1204abuts the annular portion410of the retaining element402.

The seat bushing1208in this embodiment is generally tubular in shape with an axial channel1207therethrough. The seat bushing1208comprises an upper connector portion1214that is received into the axial bore308of the tubular body302and abuts the ball seat1204. The upper connector portion1214engages the lower connector portion904of the tubular body302. In this embodiment, the lower connector portion904of the tubular body302comprises an inner threaded section908and the upper connector portion1214of the seat bushing1208comprises a complementary outer threaded section1218such that the tubular body302is threadingly engaged with the seat bushing1208. The seat bushing1208thereby secures the ball seat1204in the axial bore308against retaining element402.

The seat bushing1208in this embodiment further comprises a lower connector portion1215. The lower connector portion1215may be configured to engage a suitable downhole component including, for example, a strainer.

The barrel1206comprises a lower connector portion1212that receives the upper connector portion902of the tubular body302therein. In this embodiment, the upper connector portion902of the tubular body302comprises an outer threaded section906and the lower connector portion1212of the barrel1206comprises an inner threaded section1216such that the tubular body302threadingly engages the barrel1206.

In use, on the upstroke, the valve ball1202is raised from the ball seat1204such that the standing valve1200is open, allowing upward flow of fluid through the axial flow passage216of the insert202(via the axial channel1207of the seat bushing1208and the central opening1205of the ball seat1204) and into the barrel1206. On the downstroke, the valve ball1202is seated on the ball seat1204such that the standing valve is closed and the valve ball1202blocks fluid flow in the downhole direction.

Thus, the methods and kits disclosed herein may be used to assemble insert-type flow cage assemblies for use in standing and/or traveling valves in a downhole pump. Although specific insert structures are described herein, the methods and kits may be adapted for use with any suitable insert. In addition, the flow cage assemblies may be adapted for use with any suitable uphole and downhole components and embodiments are not limited to the specific upper and lower connections described herein.

It is to be understood that a combination of more than one of the approaches described above may be implemented. Embodiments are not limited to any particular one or more of the approaches, methods or apparatuses disclosed herein. One skilled in the art will appreciate that variations or alterations of the embodiments described herein may be made in various implementations without departing from the scope of the claims.