WO2015077252A1

WO2015077252A1 - Frack pump fluid end with integrated hydraulic valve seat release

Info

Publication number: WO2015077252A1
Application number: PCT/US2014/066226
Authority: WO
Inventors: Steven DEEL; Randal NEWMAN
Original assignee: Amerifrac Llc
Priority date: 2013-11-19
Filing date: 2014-11-18
Publication date: 2015-05-28
Also published as: US20150260177A1

Abstract

A hydraulic valve seat release system for a fluid end of a high pressure pump, comprised of method and apparatus for releasing a valve seat having a tapered outer diameter for sealingly mating when installed in the tapered interior of a fluid end suction or discharge bore via interference fit. The fluid end module of the invention includes internal high pressure porting between an exterior surface of the fluid end module and the interior surface of the bore, whereby high pressure fluid may be applied to the tapered surface of the bore and into a fluid channel around the circumference of the tapered outer diameter of the valve seat. The high pressure fluid compresses the outer diameter of the valve seat and expands the interior diameter of the bore in order to disrupt the interference fit between the valve seat and the bore thereby releasing the valve seat.

Description

FRAC PUMP FLUID END WITH

INTEGRATED HYDRAULIC VALVE SEAT RELEASE

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001 j The earlier effective filing date of U.S. Application Serial No. 61/906,017, entitled "Track Pump Fluid End with integrated Hydraulic Valve Seat Release", filed November 19, 2013, in the name of the in ventors Steven K. Dee! and Randal S. Newman. This application is also hereby incorporated by reference for all purposes as if set forth verbatim herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

{^"6002^'j Not applicable.

BACKGROUND

{0903) Field. The presently disclosed technique relates to fluid ends for high pressure pumps used in oil and gas field production, such as well servicing and hydraulic fracturing operations, and more particularly to a valve seat release system and method of use with such fluid ends,

[0004] Pi scitssjo n of Related Art. This section of this document introduces information about and^'or from the art that may provide context for or be related to the subject matter described herein and'or claimed below, it provides background information to facilitate a better understanding of the various aspects of the subject matter disclosed and claimed below . This is a discussion of "related" art. That such art is related in no way implies that it is also "prior" art. The related art may or may not be prior art. This discussion is therefore to be read in this light, and not as admissions of prior art,

[0905] The majority of high pressure pumps used in the oilfield for well service and hydraulic fracturing utilize replaceable valve seats. These valve seats ^'have a tapered outside diameter (OD) and are installed into tapered bores machined into the fluid end module. When installed the design of the tapered bores creates an interference fit between the valve seat and the module. This interference fit creates a fluid tight seal in order to prevent leakage between the valve seat and module.

(0006] As a result of this interference fit, removal of the valve seat for replacement is often difficult and at times requires specialized tools. Historically an external hydraulic cylinder and puller rod assembly has been used to pull the valve seat free of the tapered interference fit in the module. It is not uncommon to see forces of 20-30 tons required to remove tapered valve seats from the fluid end module and standard valve puller designs are capable of 1.70 tons of pull.

10007 j In addition to the concerns noted above when using external valve seat pullers, the design of some fluid ends do not allow the use of external puller assemblies. Fluid end configurations suc as the "Y" block have intersecting bores offset by 120° as opposed to valves and seats being inline or stacked vertically. In this configuration the discharge valve seats can be removed with an external valve seat puller, however the suction valve seats are not accessible, in this case, workers typically use a steel bar and sledgehammer to knock the valves out from the lower suction bore.

I^'OOOSj Furthermore, some fluid end designs such as the "Y" block noted above require the user to remove the suction manifold in order to gain access to the bore below the valve seat resul ting in increased time requirements for maintenance. Use of conventional valve seat pullers requires time to install, use, and remove which can be a time consuming task.

(0009] The presently disclosed technique is directed to resolving, or at least reducing, one or all of the problems mentioned above. Even if solutions are available to the art to address these issues, the art is always receptive to improvements or alternative means, methods and configurations. Thus., there exists a need for technique such as that disclosed herein.

SUMMARY

[0010] In a first aspect, a hydraulic valve seat release system for a fluid end of a high pressure pump, comprises: a fluid end block defining at least one of a suction bore and a discharge bore; a pressure port communicating between an exterior surface of the block and the at least one bore, the bore having a tapered interior surface; a valve seat having a tapered outer diameter and structured that in use sealably mating with the interior surface of the bore; and wherein the valve seat and the bore when mated define an annular conduit being in pressure communication with the pressure port,

19011] in a second aspect, a method for releasing a valve seat of a high pressure pump comprises: sealably mating the val ve seat within at least one of a suction bore and a discharge bore, the at least one bore being defined within a fluid end block and having a pressure port communicating between an exterior surface of the block and the bore, the bore having a tapered interior surface, the valve seat having a tapered outer diameter, and the valve seat and the bore when mated defining an annular conduit being in pressure communication with the pressure port; attaching a high pressure fluid source to the pressure port on the exterior surface of the block; applying a high pressure fluid from the source through the pressure port to the annular conduit; and releasing the valve seat by at least one of constricting the valve seat or expanding the bore by means of the fluid.

[ΘΘ12] in a third aspect, a method for the manufacture of a hydraulic valve release system for a fluid end of a high pressure pump comprises: forging a fluid end block; machining at least one of a suction bore and a discharge bore within the block, the at least one bore having a tapered interior surface; machining a high pressure port communicating between an exterior surface of the block and the bore; forging or casting a valve seat having a tapered outer diameter for sealably mating with the bore; and forming a circumferential annular conduit within at least one of the bore interior surface and the valve seat outer diameter wherein the valve seat and the bore when mated define an annular conduit being in pressure communication with the pressure port.

(0Θ13) In a fourth aspect, a hydraulic valve seat for a fluid end of a high pressure pump comprises: the valve seat having tapered outer diameter and a circumferential annular conduit within the outer diameter, the valve seat structured that in use sealably mating with a tapered interior surface of at least one of a. suction bore and a discharge bore, the at least one bore defined within a fluid end block; and wherein the valve seat and the bore when mated define an annular conduit being in pressure communication with a pressure port communicatinu between an exterior surface of the block and the interior surface of the bore. [0014] In a fifth aspect, a method for the manufacture of a hydraulic valve seat for a fluid end of a high pressure pump comprises: forging or casting the valve seat having a tapered outer diameter for sea!ably mating with a tapered interior surface of at least one of a suction bore and a discharge bore, the at least one bore defined within a fluid end block; and forming a circumferential annular conduit within the valve seat outer diameter wherein the valve seat and the bore when mated define an annular conduit being in pressure communication wit a pressure port communicating between an ex terior surface of the block and the interior surface of the bore.

[00.15] The above presents a summary of the presently disclosed subject matter in order to provide a basic understanding of some aspects thereof. The summary is not an exhaustive overview, nor is it intended to identify key or critical elements to delineate the scope of the subject matter claimed below. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The subject matter disclosed and claimed below may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which;

[0017] Figure l A-Figure I B are a partially sectioned views of a conventional Y -block fluid end of a high pressure pump.

[0018] Figure 2 A -Figure 2B depict a quintuple valve-over-valve fluid end block of a high pressure pump according to an. embodiment of the presently disclosed technique,

[0019] Figure 3 A is a cross sectional view a valve-over-valve fluid end block according to an embodiment of Figure 2 taken along line A-A therein, and Figure 3B is a detailed view of the suction bore of Figure 3 A.

[0020] Figure 4A is a side view of a valve seat assembly according to another embodiment and Figure 4B is a cross sectional view of a valve seat and valve according to the embodiment Figure 4A taken along line B-B therein. [0021 ] Figure 5 is a side view of a quintuple Y-block fluid end of a high pressure pump according to another embodiment.

{8022) Figure 6 is a cross sectional view of a Y-block fluid end according to the embodiment of Figure 5 taken along line C-C therein.

[0023] Figure 7 A is a side view of a valve seat according to another embodiment and Figure 7A is a cross sectional view of a valve seat according to an embodiment of Figure 7 A taken along line D-D therein.

10024 j While the invention is susceptible to various modifications and alternative forms, the drawings illustrate specific embodiments herein described in detail by way of example. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives failing within the spirit and scope of the invention as defined by the appended claims,

DETAILED DESCRIPTION

[0025] Illustrative embodiments of the subject matter claimed below will now be disclosed. In die interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions will be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will, vary from one implementation to another. Moreover, it will be appreciated that such a development effort, e ven if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0026] in order to address the limitations created with the use of external valve seat pullers, the presently disclosed technique includes fluid end modules with internal porting whereby high pressure hydraulic fluid and or grease can be applied to the tapered bore of the fluid end. When applied, this pressure compresses the valve seat and expands the fluid end bore, thereby freeing the valve seat from the tight interference fit. [0027] This design includes, in some embodiments, valve seats with O-ring grooves machined on the tapered OD as well as a annular conduit machined in between the O-ring grooves, in some embodiments, the grooves may be machined in the wall of the bore, Elastoraeric O-rings are installed in the grooves prior to the valve seat being installed in the fluid end module. When installed in the fluid end module, the O-rinas create a fluid tisht seal. The tapered contact surfaces of the seat and fluid end bore create and maintain the interference fit of the seat during operation of the pump,

(0028] Within the fluid end module, a pressure port is machined from an outside surface of the module and terminates in the tapered bore in an area between where the two O-rings are located. The outside surface of the module may, for example, be machined for a high pressure autoclave adapter to which a high pressure pump is connected during removal.

[00291 Removal of the valve seats is performed by attaching a high pressure pomp to the autoclave fitting noted above. As hydraulic pressure is applied to the port, fluid enters the fluid end, flows to the valve seat around the relief groove cut between the two O-rings. As pressure is increased, the valve seat is compressed and the bore in the fluid end module is expanded. This action breaks the metal to metal interference seal between the valve seat and fluid end module. Due to the tapered bore the valve seat can only move in one direction, upward.

[0030] Due to the high pressures the fluid ends are subjected to, at times in excess of 20,000 psi, certain considerations should be considered in the design of the integrated hydraulic valve seat release ("HVSR"). Such considerations include a pumping media bypass. In the event of an O-ring failure the system should withstand pressures generated by the primary pump. In the event of a crack or fluid washout in the tapered valve seat bore, the system should withstand the pressure generated by the primary pump. Such concerns also include the potential failure of O-ring to maintain pressure from the hydraulic pump when removing the valve seat. Should this occur, use of a conventional hydraulic valve seat puller would be useful j 003 ί I Turnin now to the drawings. Figure !A illustrates a conventional Y-block fluid end module 100 of a high pressure pump and Figure I B is an enlargement of the fragment B in Figure 1 A. The fluid end module 100 includes fluid cylinder 102, plunger 104, suction bore 110, and discharge bore 112. Valve seats .106, 108 are installed within the suction, bore .1 10 and discharge bore 1 12, and designed with a tapered outer diameter to create an interference fit with the correspondingly tapered interior wall of the respective bore 110, 1 12. The discharge valve seat 108 is fitted with an 0-r.ing i 14 to maintain a fluid seal between the seat 108 and the discharge bore 1 .2. Valve members 1 16, 118 sit within the valve seats 106, 108 and are spring biased in closed positions against the seats 106, 108 by valve springs 120. The top of the discharge bore .1 12 is sealed off with a discharge valve cover 122 fitted with an O-riag 124 and secured by way of retainer nut 126. Within, the suction bore 1 10 the valve member 1 1 is held in position by means of suction valve guide 128, retainer 130, pin 13:2, and pin keeper 134, jTO32] Figure 2A- Figure 2B, and Figure 3A~Figure B illustrate one particular embodiment in a quintuple valve -over-valve fluid end module 200 in accordance with the presently disclosed technique. Figure 2A~Figure2B more particularly illustrate the fluid end module 200 in a top, plan view and an eievational view, respectively. Figure 3A is a sectioned view along line A-A in Figure 2.4. Figure 3B is an enlarged view of region B indicated in Figure 3A. The fluid end module 200 includes a discharge flange 202, a gauge connection 204. a discharge flange 206, a retainer nut and cover 208, and suction manifold stud and nut 210. The fluid end module also includes a plurality of hydraulic ports 208 (only one indicated), at least one for each valve 206. j0 33j Turning now to Figure 3A~Figure 3B, suction bores 300 and discharge bores 302 are defined within the fluid end block 212, the interior surface 304, 306 of each bore being tapered for interference fit with the correspondingly tapered outer diameter of the valve seat 308, 31.0. While differences exist between suction bores and discharge bores, various embodiments operate and function, substantially the same for each bore type, and therefore discussion in reference to a suction bore shall apply equally as a discussion to a discharge bore. Any use of bore or bores without distinction shall also be construed as applying to either a suction bore or discharge bore.

(Θ634] Referring now to Figure 313, when the valve seat 308 is in its installed position within the bore 300, a annular conduit 312 around the circumference of the outer diameter of the valve seat 308, aligns with a hydraulic port 210 that provides high pressure fluid communication between the interior surface 304 of the bore 300 and the exterior surface 314 of the fluid end block 212. A high pressure fixed coupling 316 is attached to the hydraulic port 210 at the block's exterior surface 314.

[0035] To unseat the valve seat, a high pressure pump or other source of high pressure fluid, (not shown) is attached to the coupling 316 and fluid is pumped through the port 210 to the annular conduit 312 of the valve seat 308, The high pressure of the fluid causes either the outer diameter of the val ve seat 308 to constrict o the interior surface 304 of the bore 300 to expand, or both, thereby releasing the interference fit between the valve seat 308 and the bore 300 to allow removal of the valve seat 308,

(003 1 In order to remove and replace the valve seats, whether from a fluid end configured as val ve-o ver-valve or a Y-block, one particular sequence of steps comprises first removing the discharge cover; followed b the valve spring and discharge valve, A high pressure fluid source is then attached to the high pressure fixed coupling and high pressure fluid is introduced into the annular conduit via the hydraulic port. The increased pressure acts to compress the circumference of the valve seat and or expand the diameter of the interior surface of the bore thereby interrupting the interference fit between the valve seat and the bore. Once released, or dislodged, the valve seat may be removed.

|ΘΘ37] O ce the discharge valve has been removed, the suction bore can be accessed. One particular sequence for removal of the valve seat from the suction bore comprises first removing the suction valve pin, retainer, guide and spring. A high pressure fluid source can then be attached to the high pressure fixed coupling of the suction bore's hydraulic port and the valve seat released by high fluid pressure as discussed above for the discharge bore's valve seat.

|003S| in Figure 3B, the outer diameter of the valve seat 308 is further installed with two O-rings 318, 320: an upper 0-r.ing 318 above the annular conduit 3.12 and a lower 0-r.ing 320 below the annular conduit 312. The O-rings 318, 320 provide a fluid-tight seal sufficient, to keep the high pressure fluid introduced through the hydraulic port 210 from leaking into the bore 300 until the interference fit is sufficiently released to allow removal of the valve seat 308, 310. (0039) Alternative embodiments of the presently disclosed technique may also be realized. For example. Figure 4A and Figure 4B illustrate one particular embodiment of a double O-ring valve assembly 400. Figure 4A is an elevational view and Figure 4B is a sectioned view along line 8-B in Figure 4A. The valve assembly includes a valve member 402 seated on the valve seat 404, The valve seat 404 includes tapered outer diameter 406 into which a annular conduit 408 is formed and upper and lower O-rings 410, 12 are fitted. The interior surface of the bore (not shown) is finished smoothly. Thus, the annular conduit and the O-rings may be place on either the interior surface of the bore as in Figure 3 A and Figure 3B or on the valve seat as in Figure 4A and Figure 4B. Note also that there may he embodiments wherein the annular conduit is formed on either the interior surface of the bore or on the valve seat and the O-rings are place on the other of those two locations.

(0040) Figure 5 and Figure 6 illustrate another particular embodiment 500 of the hydraulic valve seat release system in a fluid end Y-block module. Figure 5 is an. elevational view and Figure 6 is a sectioned view along line C~C in Figure 5. in Figure 5 and Figure 6. like parts to the embodiment of Figure 2A-Figure 2B and Figure 3A-Figure 3B bear like numbers. Note how readily the technique may be adapted to different configurations of the fluid end module.

[0041] Figure 7A and Figure 7B illustrate modification of a conventional single O-ring valve seat 700 in accordance with the presently disclosed technique. Figure 7.4 is an elevational view of the valve seat 700 and Figure 78 is a sectioned view along the line D-D in Figure 7A. The valve seat is modified by machining of an annular conduit 702 into the tapered exterior surface 704 of the valve seat in a position below the existing O-ring channel 706, and further adding a lower O-ring channel 708 below the annular conduit 702. Those ordinarily skilled in the art having the benefit of this disclosure will be able to readily implement such a modification with existing knowledge and tooling.

|0O42{ In an alternate embodiment (not shown), the annular conduit surrounding the circumference of the valve seat is formed b a fluid channel in the tapered interior surface of the bore, rather than the valve seat itself having a fluid channel In this embodiment, a circumferential annular conduit is defined in combination by the interior surface of the bore and valve seat when sea!ingly mated with the annular conduit being in fluid communication with the hydraulic port. [Θ043] Those in the art having the benefit of this disclosure will appreciate thai the sealing elements other than O-rings might be used in various alternative embodiments. Thus, the O-rings disclosed herein are, by way of example and illustration, just one means for sealing by which the disclosed sealing function may be implemented. Indeed, some embodiments may not even need to use separate sealing elements where appropriate levels of sealin can be achieved without them,

(0044] Similarly, the placement of the annular conduit and any sealing elements, where used, is not material so long as they provide a fluid-right seal sufficient to keep the high pressure fluid introduced through the hydraulic port .from leaking into the bore until the interference fit is sufficiently released to allow removal of the valve seat. Thus, various embodiments might use a conventional valve seat with a groove cut in the block; or; a valve seat with a groove therein and block with a groove therein; or, a valve seat with a groove but no seal ing element on either the block or seat; or a block wit a groo ve therein and no sealing element on block or seat; or those embodiments disclosed herein. These, and still other variations, are all within the scope of the subject matter claimed below.

|ΘΘ45| Valve seats in accordance with the presently disclosed technique may be manufactured from forgings or castings. Such forgings and castings are well known in the art and any suitable forging or casting technique known to the art may be used. Accordingly, so as to avoid obscuring that which is otherwise disclosed and claimed herein, further discussion of such techniques shall be omitted. The annular conduit may he formed in the valve seat by the castings, or by machining. Any portion of the annular conduit formed in the interior surface of the bore may be formed by machining, and hydraulic ports may be machined into the forged fluid end block.

{0046] The presently disclosed technique therefore includes method and apparatus for releasing a valve seat front a suction bore or a discharge bore of a high pressure pump fluid end. A valve seat having a tapered outer diameter for sealingly mating with the tapered interior diameter of a fluid end bore via interference fit. The fluid end module includes internal high pressure porting between an exterior surface of the fluid end module and the interior surface of the bore, whereby high pressure fluid ma be appl ied to th tapered surface of the bore and into a fluid channel around the circumference of the tapered outer diameter of the valve seat. The high pressure fluid compresses the outer diameter of the valve seat and expands the interior diameter of the bore in order to disrupt the interference fit between the valve seat and the bore, thus releasing the valve seat. The valve seats are, in some embodiments, installed with two O-rinus one above and one below the valve seat fluid channel— providing a fluid tight seal

|9047| This concludes the detailed description. The particular embodiments disclosed above are illustrative only, as the invention ma be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein, shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and ail such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.

Claims

WHAT IS CLA IMED:

1. A hydraulic valve seat release system for a fluid end of a high pressure pump, coiTipnsing;

a .fluid end block defining at least one of a suction bore and a discharge bore;

a pressure port fluidly communicating between an exterior surface of the block, and the at least one bore, the bore having a tapered interior surface; and

a valve seat having a tapered outer diameter that, in use, sealably mates with the interior surface of the bore;

wherein the valve seat and the bore when mated define an annular conduit being in pressure communication with the pressure port and fluidly sealed from the bore.

2, The hydraulic valve seat release system of claim I , wherein the annular conduit is defined at least in part by the interior surface of the bore.

3. The hydraulic valve seat release system of claim 2, wherein the annular conduit is further defined at least in part by the outer diameter of the val ve seat,

4. The hydraulic valve seat release system of claim 12, wherein the annular conduit is defined at least in part by the outer diameter of the valve seat.

5. The hydraulic valve seat release system of claim 1 , further comprising at least one sealing element sealing the annular conduit from the bore.

6. The hydraulic valve seat release system of claim 5, wherein the sealing element comprises means for sealing the fluid conduit from the bore.

7. The hydraulic valve seat release system of claim 6, wherein the means for sealing comprises an elastomeric O-ring.

8. The hydraulic valve seat release system of claim. 5, wherein the sealing element comprising an elastomeric O-ring.

9. A method for releasing a valve seat in the fluid end block of a high pressure pump, comprising: sealably mating the valve seat within at least one of a suction bore and a discharge bore,;

applying a high pressure fluid through a pressure port extending from the external surface of the fluid end block to an annular conduit defined by at least one of the interior surface of the bore and the valve seat when the interior surface and the valves seat, are mated; and

releasing the valve seat by constricting the valve seat or expanding the bore by means of the fluid.

10. The method of claim 9, wherein the annular conduit is defined by the interior surface of the bor e .

I I . The method of chum 10, wherein the annular conduit is further defined by the valve seat,

12. The method of claim 9, wherein the annular condui t is defined by the valve seat

13. The method of claim 9, wherein sealably mating the valve seat with at least one of the suction bore and the discharg bore includes disposing at least one sealing element to fhiidly sea! the annular conduit from the bore.

14. The method of claim 13, wherein the sealing element comprises an elastomeric firing,

15. A method for the manufacture of a hydraulic valve release system for a fluid end of a high pressure pump, comprising:

forging a fluid end block;

machining at least one of a suction bore and a discharge bore within the block, the at least one bore having a tapered interior surface;

machining a high pressure port communicating between an exterior surface of the block and the bore;

forging or casting a valve seat having a tapered outer diameter for sealably mating with the bore; and

forming a circumferential annular conduit within at least one of the bore interior surface and the valve seat outer diameter wherein the valve seat and the bore when mated define an an ular conduit be ng m pressure eommunkafion with the pressure port.

16. A hydraulic valve seat for a fluid end block of a high pressure pump, comprising: the valve seat having a tapered outer diameter and a circumferential annular conduit within the outer diameter, the valve seat structured so that irs use the valve seat sealab!y mates with a tapered interior surface of at least one of a suction bore and a discharge bore, the at least, one bore defined within a fluid end block; and

wherein the vaive seat and the bore when mated defme an annular conduit being in pressure communication with a pressure port communicating between an exterior surface of the block and the interior surface of the bore,

17. The hydraulic valve seat of claim 16, wherein the valve seat defines the annular conduit in conj unction with the interior surface of the bore.

38. The hydraulic valve seat of claim 16, wherein the valve seat defines the annular conduit to the exclusion of the interior surface of the bore.

19, The hydraulic vaive seat of claim 16, wherein the valve seat includes at least one channel m which a sealing element may be disposed.

20, A method for the manufacture of a hydraulic valve seat for a fluid end of a high pressure pump, comprising;

forming the vaive seat having a tapered outer diameter for sealably mating with a tapered interior surface of at least one of a suction bore and a discharge bore, the at least one bore defined within a fluid end block; and

forming a circumferential annular conduit within the valve seat outer diameter wherein the valve seat and the bore when mated define an annular conduit being in pressure communication with a pressure port communicating between an exterior surface of the block and the interio surface of the bore.