PUMP SYSTEM

Abstract

A new and improved long stroke pump system used for wellbore hydraulic fracturing operations. The pump system comprises a power system, a drive system, and a frac fluid pumping assembly. The frac fluid pumping assembly comprises one or more pairs of hydraulic cylinders that are mechanically decoupled from each other but are hydraulically coupled to each other.

Description

BACKGROUND

Field

Embodiments of the disclosure generally relate to a pump system used for wellbore hydraulic fracturing operations.

Description of the Related Art

Current high pressure pump systems used for the hydraulic fracturing of wellbores are subject to severe operating conditions that often result in damage, operating failures, and reduced service life of various pump system components, which reduce reliability and increase maintenance cost. Therefore, there is a need for new and improved pump systems.

SUMMARY

A new and improved long stroke pump system used for wellbore hydraulic fracturing operations is described herein. The pump system comprises a power system, a drive system, and a frac fluid pumping assembly. The frac fluid pumping assembly comprises one or more pairs of hydraulic cylinders that are mechanically decoupled from each other but are hydraulically coupled to each other.

Each pair of hydraulic cylinders are mechanically decoupled because there is no direct mechanical linking or coupling that transfers energy from one hydraulic cylinder to the other hydraulic cylinder. Mechanical energy generated from one of the hydraulic cylinders is not transferred to the other hydraulic cylinder during operation. Each pair of hydraulic cylinders are hydraulically coupled because energy is transferred from one hydraulic cylinder to the other hydraulic cylinder through an operating hydraulic fluid. Hydraulic energy generated from one of the hydraulic cylinders is used to help actuate the other hydraulic cylinder during operation. In addition, the hydraulic cylinders are dimensioned to allow retraction of a plunger from a corresponding spacer spool and/or fluid end for ease of access to repair, perform maintenance, and/or replace the plunger the spacer spool, and/or any components of the plunger and/or the spacer spool.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

FIG. 1 illustrates a long stroke pump system used for wellbore hydraulic fracturing operations, according to one or more embodiments.

FIG. 2 illustrates another view of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 3 illustrates another view of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 4 illustrates another view of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 5 illustrates a top view of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 6 illustrates a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 7 illustrates a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 8 illustrates a sectional view of a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 9 illustrates a sectional view of a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 10 illustrates a sectional view of a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 11 illustrates a sectional view of a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 12 illustrates a sectional view of a portion of the long stroke pump system of FIG. 1, according to one or more embodiments.

FIG. 13 illustrate a portion of a long stroke pump system used for wellbore hydraulic fracturing operations, according to one or more embodiments.

FIG. 14 illustrates a portion of the long stroke pump system of FIG. 13, according to one or more embodiments.

FIG. 15A schematically illustrates a portion of a long stroke pump system in a first operational position, according to one or more embodiments.

FIG. 15B schematically illustrates the portion of the long stroke pump system of FIG. 15A in a second operational position, according to one or more embodiments.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.

DETAILED DESCRIPTION

The present disclosure contemplates that use of terms such as “coupled,” “couple(s)”, and/or “coupling,” can include direct coupling and/or indirect coupling, such as coupling through other components. The present disclosure also contemplates that use of terms such as “coupled,” “couple(s)”, and/or “coupling,” can include but are not limited to connecting, welding, interference fitting, brazing, and/or fastening using fasteners, such as pins, rivets, screws, bolts, and/or nuts. The present disclosure also contemplates that use of terms such as “coupled,” “couple(s)”, and/or “coupling,” can include but are not limited to components being integrally formed together as a unitary body. The present disclosure also contemplates that the use of terms such as “coupled,” “couple(s)”, and/or “coupling,” can include operable coupling such as mechanical coupling, electrical coupling, and/or hydraulic (e.g. fluidly) coupling.

FIGS. 1-7 illustrate a long stroke pump system 1000 used for wellbore hydraulic fracturing operations, according to one or more embodiments. The long stroke pump system 1000 comprises a fluid reservoir 1010, a power system 1020, a drive system 1030, a fluid coupling 1040, and a frac fluid pumping assembly 1050. In one or more embodiments, the drive system and/or the fluid coupling 1040 for part of the frac fluid pumping assembly 1050. The long stroke pump system 1000 is supported on a trailer 1060, which can move the long stroke pump system 1000 to and from one or more well sites.

The fluid reservoir 1010 contains an operating fluid that is pumped by the drive system 1030 to operate the frac fluid pumping assembly 1050. The drive system 1030 is powered by the power system 1020. The drive system 1030 may comprise one or more pumps 1031 and one or more pump manifolds 1032. The power system 1020 may comprise a motor 1021 and/or a turbine 1022. The motor 1021 of the power system 1020 may comprise a diesel engine, a gasoline engine, and/or an electric motor. The drive system 1030 is fluidly coupled to the frac fluid pumping assembly 1050 by a fluid coupling 1040. The fluid coupling 1040 may comprise one or more fluid lines/valves 1041 and/or coupling manifolds 1043 arranged to supply and return the operating fluid to and from the frac fluid pumping assembly 1050.

One or more hydraulic cylinders 1051 may be coupled to a fluid end assembly 1054 via one or more spacer frames 1052 and/or one or more spacer spools 1053. The fluid end assembly 1054 comprises one or more fluid ends 1055 that are in fluid communication with a discharge manifold 1056 (having an outlet 1059) and a suction manifold 1057 (having inlets 1058). One or more plungers 1045 extend from the one or more hydraulic cylinders 1051 to the fluid ends 1055.

Referring to FIGS. 1-7, the operating fluid is pumped into and out of the one or more hydraulic cylinders 1051 of the frac fluid pumping assembly 1050 via the pumps 1031 and the pump manifolds 1032 of the drive system 1030. The fluid coupling 1040 may also comprise a coupling manifold 1043 that is in fluid communication with the pump manifolds 1032 via one or more fluid lines/valves 1041, such as hoses and/or check valves. The coupling manifold 1043 is also in fluid communication with the hydraulic cylinders 1051 via one or more fluid lines/valves 1041, such as hoses and/or check valves. Only a few pairs of the fluid lines/valves 1041 are illustrated in FIGS. 1-5 and have been removed from FIGS. 6-12 for clarity.

In one or more embodiments, the fluid lines/valves 1041 may comprise two inlet hoses to pump operating fluid into a pair of hydraulic cylinders 1051 (via one or more hydraulic cylinder inlets 1071), two outlet hoses to return fluid from the pair of hydraulic cylinders 1051 (via one or more hydraulic cylinder outlets 1072), and two relief hoses to also return a portion of the operating fluid from the pair of hydraulic cylinders 1051 (via one or more hydraulic cylinder relief ports 1073). The hydraulic cylinders 1051 may each include a sensor port 1074 in which a sensor can be support to measure one or more operational parameters of the hydraulic cylinders 1051.

Referring to FIGS. 8-12, each hydraulic cylinder 1051 has a cylinder housing 1080 and a cylinder rod 1081 that extends out of the cylinder housing 1080. A piston 1082 is coupled to one end of the cylinder rod 1081 and is disposed within the cylinder housing 1080. The piston 1082 is in sealing contact with the cylinder housing 1080 forming a fluid chamber 1083A (e.g. a pump side fluid chamber) and a fluid chamber 1083B (e.g. a plunger side fluid chamber) on opposite sides of the piston 1082 into which operating fluid is supplied (e.g. pumped) into and returned out of. A fluid line/port 1099 (as shown in FIG. 12) may be formed between each pair of hydraulic cylinders 1051 to provide fluid communication between the sealed fluid chambers 1083B on one side of the pistons 1082 formed within the cylinder housings 1080. The fluid line/port 1099 may be formed through the cylinder housings 1080, one or more flanged end connections 1085 of the cylinder housings 1080, and/or a support frame 1086 disposed between the cylinder housings 1080.

The opposite end of the cylinder rod 1081 is coupled to the plunger 1045 via a coupling 1087 (and or disposed at least partially within the plunger 1045). The plunger 1045 sealingly extends into one end of one of the spacer spools 1053. A length (L1) of each cylinder housing 1080 is dimensioned to allow the plunger 1045 to be fully retracted from the spacer spool 1053 via the cylinder rod 1081 for ease of access to repair, perform maintenance, and/or replace the plunger 1045 and/or a seal assembly 1089 of the plunger 145 and/or the spacer spool 1053.

The opposite end of the spacer spool 1053 is coupled to one of the fluid ends 1055 of the fluid end assembly 1054. The internal area of each spacer spool 1053 forms a fluid chamber 1094 that is in fluid communication with a fluid chamber 1096 formed in the fluid end 1055 that is coupled to the spacer spool 1053. Each of the fluid ends 1055 are in fluid communication with the suction manifold 1057 and the discharge manifold 1056 of the fluid end assembly 1054. Each of the fluid ends 1055 comprise a suction valve assembly 1091 and a discharge valve assembly 1092 configured to direct fracing fluid into and out of the fluid chambers 1096 of the fluid ends 1055 via the suction manifold 1057 and the discharge manifold 1056.

As indicated by reference arrow 1095 shown in FIG. 8, the plunger 1045 is repeatedly stroked back and forth (via the cylinder rod 1081) to draw fracing fluid into the fluid ends 1055 and pump the fracing fluid out of the fluid ends 1055. The fracing fluid flows into the fluid end 1055 through the suction manifold 1057 and then the suction valve assembly 1091 as the plunger 1045 is stroked in a direction away from the fluid end 1055. The fracing fluid flows out of the fluid end 1055 through the discharge valve assembly 1092 and then discharge manifold 1056 as the plunger 1045 is stroked in direction toward the fluid end 1055. A valve cover 1093 secures and seals at least the discharge valve assembly 1092 in the fluid end 1055.

Each of the spacer frames 1052 may comprise one or more stay rods 1098 and/or one or more stay rod housings 1097 coupled at one end to the support frame 1086. The support frame 1086 and the spacer frames 1052 may be used to support the hydraulic cylinders 1051, the cylinder rods 1081, the plungers 1045, the spacer spools 1053, and/or the fluid ends 1055 via one or more connections, such as threaded and/or flanged connections. For example, each pair of hydraulic cylinders 1051 may be coupled to the support frame 1086, such that three pairs of hydraulic cylinders 1051 would require three support frames 1086.

FIGS. 13 and 14 illustrate an embodiment of the fluid coupling 1040 configured to supply and return operating fluid between the drive system 1030 and the hydraulic cylinders 1051. Each pump 1031 and pump manifold 1032 is configured to supply and return operating fluid to a pair of hydraulic cylinders 1051. Therefore, three pumps 1031 and three pump manifolds 1032 supply and return operating fluid to three pairs (i.e. six) hydraulic cylinders 1051. The fluid coupling 1040 has two inlet hoses 1046 to pump operating fluid into each pair of hydraulic cylinders 1051 (such as via hydraulic cylinder inlets 1071 as shown in FIG. 7), two outlet hoses 1047 to return fluid from each pair of hydraulic cylinders 1051 (such as via hydraulic cylinder outlets 1072 as shown in FIG. 7), and two relief hoses 1048 to also return a portion of the operating fluid from each pair of hydraulic cylinders 1051 (such as via hydraulic cylinder relief ports 1073 as shown in FIG. 7).

FIGS. 15A and 15B schematically illustrates a portion of a long stroke pump system 2000 (such as the long stroke pump system 1000) in a first operational position and a second operational position, according to one or more embodiments. Specifically, FIGS. 15A and 15B illustrate a hydraulic coupling of a pair of hydraulic cylinders 2001 and 2002. The hydraulic cylinders 2001, 2002 are mechanically decoupled from each other but are hydraulically coupled to each other as further described below.

With reference to FIG. 15A, the hydraulic cylinder 2001 is moving in a suction stroke and the hydraulic cylinder 2002 is moving in a discharge stroke. An operating fluid from a fluid chamber 2003 (e.g. a pump side fluid chamber) on the first side of a piston 2005 of the hydraulic cylinder 2001 is pumped via a pump 2015 and/or pushed out of the hydraulic cylinder 2001, flows through a pump manifold 2006, and is directed into a fluid chamber 2007 (e.g. a pump side fluid chamber) on the first side of a piston 2008 of the hydraulic cylinder 2002. A portion or the entire operating fluid from fluid chamber 2003 may optionally be directed from the pump manifold 2006 to a fluid reservoir (such as fluid reservoir 1010 as shown in FIG. 1). A portion or the entire operating fluid pumped into fluid chamber 2007 may optionally be supplied through the pump manifold 2006 from the same of a different fluid reservoir (such as fluid reservoir 1010 as shown in FIG. 1). Although only one fluid line from each hydraulic cylinder 2001 and 2002 to the pump manifold 2006 is schematically shown, any number of fluid lines (such as two, three, four, five, six or more) may be used to supply, return, and/or relieve operating fluid from each hydraulic cylinder 2001 and 2002 through the pump manifold 2006.

The pressurized operating fluid pumped into the fluid chamber 2007 moves the piston 2008, a cylinder rod 2009, and a plunger 2010 in a direction toward a fluid end 2 in a discharge stroke. As the piston 2008 moves in the direction toward the fluid end 2, the operating fluid in a fluid chamber 2011 (e.g. a plunger side fluid chamber) on the opposite, second side of the piston 2008 of the hydraulic cylinder 2002 is pressurized and forced out of the fluid chamber 2011. The pressurized operating fluid flows from the fluid chamber 2011 into a fluid chamber 2004 (e.g. a plunger side fluid chamber), which moves the piston 2005, a cylinder rod 2012, and a plunger 2013 of the hydraulic cylinder 2001 in a direction toward the pump 2015 and the pump manifold 2006 in the suction stroke. A fluid line 2014 between fluid chambers 2004 and 2011 may be an external fluid line between cylinder housings of the hydraulic cylinders 2001, 2001 and/or may be an internal fluid line ported through the cylinder housings, flanged end connections, and/or support frames (as shown in FIG. 12 for example).

Hydraulic energy generated from the pressurized operating fluid in the fluid chamber 2011 (when compressed by the piston 2008 in the hydraulic cylinder 2002) is supplied into the fluid chamber 2004 via fluid line 2014 and used to help move the piston 2005, the cylinder rod 2012, and thus the plunger 2013 of the hydraulic cylinder 2001. Hydraulic energy generated from the pressurized operating fluid in the fluid chamber 2003 (when compressed by the piston 2005 in the hydraulic cylinder 2001) and/or pressurized operating fluid by the pump 2015 can be supplied via the pump manifold 2006 into the fluid chamber 2007 and used to help move the piston 2008, the cylinder rod 2009, and thus the plunger 2010 of the hydraulic cylinder 2002. In this manner, the hydraulic cylinders 2001, 2002 are mechanically decoupled from each other but are hydraulically coupled to each other.

A portion of operating fluid from fluid chamber 2011 may optionally be directed through a relief line 2016 to the pump manifold 2006 and to a fluid reservoir (such as fluid reservoir 1010 as shown in FIG. 1). Although only one relief line 2016 is schematically shown, any number of fluid lines may be used to relieve operating fluid from each hydraulic cylinder 2001 and 2002 through the pump manifold 2006. Although the relief line 2016 is schematically shown external to the hydraulic cylinders 2001, 2002, the relief line 2016 may be ported internally through cylinder housings of the hydraulic cylinders 2001, 2002.

During the discharge stroke, fracing fluid is pumped out of a spacer spool 2017 and the fluid end 2 via a discharge valve assembly and a discharge manifold (such as the discharge valve assembly 1092 and the discharge manifold 1056 of the long stroke pump system 1000). As the piston 2008 and the cylinder rod 2009 (and thus the plunger 2010) of the hydraulic cylinder 2002 are moving in the direction of the discharge stroke, the piston 2005 and the cylinder rod 2012 (and thus the plunger 2013) of the hydraulic cylinder 2001 are moving in an opposite direction toward the pump 2015 and the pump manifold 2006 in the suction stroke. During the suction stroke, fracing fluid is pumped into a spacer spool 2018 and the fluid end 1 via a suction valve assembly and a suction manifold (such as the suction valve assembly 1091 and the suction manifold 1057 of the long stroke pump system 1000).

With reference to FIG. 15B, the operating fluid from the fluid chamber 2007 of the hydraulic cylinder 2002 is pumped via the pump 2015 and/or pushed out of the hydraulic cylinder 2002, flows through the pump manifold 2006, and is directed back into the fluid chamber 2003 of the hydraulic cylinder 2001. A portion or the entire operating fluid from fluid chamber 2007 may optionally be directed from the pump manifold 2006 to a fluid reservoir (such as fluid reservoir 1010 as shown in FIG. 1). A portion or the entire operating fluid pumped into fluid chamber 2003 may optionally be supplied through the pump manifold 2006 from a fluid reservoir (such as fluid reservoir 1010 as shown in FIG. 1).

The pressurized operating fluid pumped into the fluid chamber 2003 of the hydraulic cylinder 2001 moves the piston 2005, the cylinder rod 2012, and the plunger 2013 in a direction toward the fluid end 1 in a discharge stroke. As the piston 2005 moves in the direction toward the fluid end 1, the operating fluid in the fluid chamber 2004 on the opposite, second side of the piston 2005 of the hydraulic cylinder 2001 is pressurized and forced out of the fluid chamber 2004. The pressurized operating fluid flows from fluid chamber 2004 into fluid chamber 2011 of the hydraulic cylinder 2002, which helps moves the piston 2008, the cylinder rod 2009, and the plunger 2010 of hydraulic cylinder 2002 in a direction toward the pump 2015 and the pump manifold 2006 in a suction stroke.

Hydraulic energy generated from the pressurized operating fluid in the fluid chamber 2004 (when compressed by the piston 2005 in the hydraulic cylinder 2001) is supplied into the fluid chamber 2011 via fluid line 2014 and used to help move the piston 2008, the cylinder rod 2009, and thus the plunger 2010 of the hydraulic cylinder 2002. Hydraulic energy generated from the pressurized operating fluid in the fluid chamber 2007 (when compressed by the piston 2008 in the hydraulic cylinder 2002) and/or pressurized operating fluid by the pump 2015 can be supplied via the pump manifold 2006 into the fluid chamber 2003 and used to help move the piston 2005, the cylinder rod 2012, and thus the plunger 2013 of the hydraulic cylinder 2001. In this manner, the hydraulic cylinders 2001, 2002 are mechanically decoupled from each other but are hydraulically coupled to each other.

During the discharge stroke, fracing fluid is pumped out of the spacer spool 2018 and the fluid end 1 via the discharge valve assembly and the discharge manifold. As the piston 2005 and the cylinder rod 2012 (and thus the plunger 2013) of the hydraulic cylinder 2001 are moving in the direction of the discharge stroke, the piston 2008 and the cylinder rod 2009 (and thus the plunger 2010) of the hydraulic cylinder 2002 are moving in an opposite direction toward the pump 2015 and the pump manifold 2006 in a suction stroke. During the suction stroke, fracing fluid is pumped into the spacer spool 2017 and the fluid end 2 via the suction valve assembly and the suction manifold. The operating fluid is repeatedly pumped into and out of the hydraulic cylinders 2001, 2002 as described above to provide suction, pressurization, and discharge of fracing fluid through the fluid ends 1 and 2 to conduct wellbore hydraulic fracturing operations.

The long stroke pump systems 1000, 2000 may be arranged such that the pistons/rods/plungers move at suction and discharge strokes of about 10-50 strokes per minute, for example 20 strokes per minute, which is in contrast to about 150+ strokes per minute for conventional pump systems. The longer and slower pump strokes of the long stroke pump systems 1000, 2000 provide a reduced wear of the components and therefore longer service/maintenance times. Any one more components of the long stroke pump systems 1000 and/or 2000 may be combined with any other one or more components of the long stroke pump systems 1000 and/or 2000.

In one or more embodiments, the frac fluid pumping assembly comprises a first pair of hydraulic cylinders that are mechanically decoupled from each other but that are hydraulically coupled to each other. The frac fluid pumping assembly may further comprise a second pair of hydraulic cylinders that are mechanically decoupled from each other but that are hydraulically coupled to each other. The frac fluid pumping assembly may further comprise a third pair of hydraulic cylinders that are mechanically decoupled from each other but that are hydraulically coupled to each other. The frac fluid pump assembly may comprise any number of pairs of hydraulic cylinders that are mechanically decoupled from each other but that are hydraulically coupled to each other.

In one or more embodiments, a frac fluid pumping assembly comprises a first pair of hydraulic cylinders each having a cylinder rod extending at least partially from the first pair of hydraulic cylinders, wherein the first pair of hydraulic cylinders are mechanically decoupled from each other but are hydraulically coupled to each other; a first pair of spacer spools; a first spacer frame coupled at one end to the first pair of hydraulic cylinders and at an opposite end to the first pair of spacer spools; and a fluid end assembly having a pair of fluid ends coupled to the first pair of spacer spools, wherein a plunger of each fluid end is coupled to one of the cylinder rods of the first pair of hydraulic cylinders.

Each hydraulic cylinder comprises a cylinder housing, the cylinder rod at least partially disposed within the cylinder housing, and a piston coupled to the cylinder rod and forming fluid chambers within the cylinder housing. The first pair of hydraulic cylinders are hydraulically coupled to each other such that an operating fluid is repeatedly pumped from the fluid chamber of one of the hydraulic cylinders into the fluid chamber of the other hydraulic cylinder and then back. As the operating fluid is pumped out of one of the hydraulic cylinders, the cylinder rod of that hydraulic cylinder is at least partially further extended out of that cylinder housing in a discharge stroke. As the operating fluid is pumped into one of the hydraulic cylinders, the cylinder rod of that hydraulic cylinder is at least partially retracted back into the cylinder housing in a suction stroke.

When the cylinder rod of one of the hydraulic cylinders is moved in a first direction in the discharge stroke, the cylinder rod of the other hydraulic cylinder is moved in an opposite, second direction in the suction stroke. Each plunger is at least partially disposed within one of the spacer spools that is coupled to one of the fluid ends. A length of each cylinder housing is dimensioned to allow each plunger to be fully retracted from each spacer spool. Each fluid end comprises a suction valve assembly configured to direct fluid into the fluid end, and a discharge valve assembly configured to direct fluid out of the fluid end. Each fluid end is in fluid communication with a suction manifold and a discharge manifold.

The frac fluid pumping assembly further comprises a second pair of hydraulic cylinders that are mechanically decoupled from each other but are hydraulically coupled to each other. The frac fluid pumping assembly further comprises a third pair of hydraulic cylinders that are mechanically decoupled from each other but are hydraulically coupled to each other.

In one or more embodiments, a pump system comprises a power system, a drive system, and any of the embodiments of the frac fluid pumping assembly as described herein. The drive system comprises one or more pumps and one or more pump manifolds configured to direct the operating fluid between the pairs of hydraulic cylinders that are hydraulically coupled to each other. The power system is configured to power the one or more pumps.

In one or more embodiments, a frac fluid pumping assembly comprises a first hydraulic cylinder comprising a first cylinder housing, a first cylinder rod at least partially disposed within the first cylinder housing, and a first piston coupled to the first cylinder rod and forming a pump side fluid chamber and a plunger side fluid chamber within the first cylinder housing on opposite sides of the first piston; a second hydraulic cylinder comprising a second cylinder housing, a second cylinder rod at least partially disposed within the second cylinder housing, and a second piston coupled to the second cylinder rod and forming a pump side fluid chamber and a plunger side fluid chamber within the second cylinder housing on opposite sides of the second piston; and a pump configured to pump operating fluid into the pump side fluid chamber within the first cylinder housing, and configured to pump operating fluid into the pump side fluid chamber within the second cylinder housing, wherein the plunger side fluid chamber of the first cylinder housing is in fluid communication with the plunger side fluid chamber of the second cylinder housing.

The first cylinder rod is coupled to a first plunger that extends into a first fluid end, and wherein the second cylinder rod is coupled to a second plunger that extends into a second fluid end. Operating fluid is supplied from the plunger side fluid chamber of the first cylinder housing into the plunger side fluid chamber of the second cylinder housing to move the second piston, the second cylinder rod, and the second plunger in a suction stroke to draw fluid into the second fluid end. Operating fluid is supplied from the plunger side fluid chamber of the second cylinder housing back into the plunger side fluid chamber of the first cylinder housing to move the first piston, the first cylinder rod, and the first plunger in a suction stroke to draw fracing fluid into the first fluid end. When the first piston, the first cylinder rod, and the first plunger move in the suction stroke, the second piston, the second cylinder rod, and the second plunger move in a discharge stroke to pump fracing fluid out of the second fluid end.

Benefits of the embodiments of the long stroke pump system as disclosed herein include increased efficiency, reduced costs, reduced operational times, decreased mobilization of resources, and simplicity in design and operations.

It will be appreciated by those skilled in the art that the preceding embodiments are exemplary and not limiting. It is intended that all modifications, permutations, enhancements, equivalents, and improvements thereto that are apparent to those skilled in the art upon a reading of the specification and a study of the drawings are included within the scope of the disclosure. It is therefore intended that the following appended claims may include all such modifications, permutations, enhancements, equivalents, and improvements. The present disclosure also contemplates that one or more aspects of the embodiments described herein may be substituted in for one or more of the other aspects described. The scope of the disclosure is determined by the claims that follow.

Claims

1. A frac fluid pumping assembly, comprising: a first pair of hydraulic cylinders each having a cylinder rod extending at least partially from the first pair of hydraulic cylinders, wherein the first pair of hydraulic cylinders are mechanically decoupled from each other but are hydraulically coupled to each other;a first pair of spacer spools;a first spacer frame coupled at one end to the first pair of hydraulic cylinders and at an opposite end to the first pair of spacer spools; anda fluid end assembly having a pair of fluid ends coupled to the first pair of spacer spools, wherein a plunger of each fluid end is coupled to one of the cylinder rods of the first pair of hydraulic cylinders.

2. The frac fluid pumping assembly of claim 1, wherein each hydraulic cylinder comprises a cylinder housing, the cylinder rod at least partially disposed within the cylinder housing, and a piston coupled to the cylinder rod and forming fluid chambers within the cylinder housing.

3. The frac fluid pumping assembly of claim 2, wherein the first pair of hydraulic cylinders are hydraulically coupled to each other such that an operating fluid is repeatedly pumped from the fluid chamber of one of the hydraulic cylinders into the fluid chamber of the other hydraulic cylinder and then back.

4. The frac fluid pumping assembly of claim 3, wherein as the operating fluid is pumped out of one of the hydraulic cylinders, the cylinder rod of that hydraulic cylinder is at least partially further extended out of that cylinder housing in a discharge stroke.

5. The frac fluid pumping assembly of claim 4, wherein as the operating fluid is pumped into one of the hydraulic cylinders, the cylinder rod of that hydraulic cylinder is at least partially retracted back into the cylinder housing in a suction stroke.

6. The frac fluid pumping assembly of claim 5, wherein when the cylinder rod of one of the hydraulic cylinders is moved in a first direction in the discharge stroke, the cylinder rod of the other hydraulic cylinder is moved in an opposite, second direction in the suction stroke.

7. The frac fluid pumping assembly of claim 6, wherein each plunger is at least partially disposed within one of the spacer spools that is coupled to one of the fluid ends.

8. The frac fluid pumping assembly of claim 7, wherein a length of each cylinder housing is dimensioned to allow each plunger to be fully retracted from each spacer spool.

9. The frac fluid pumping assembly of claim 7, wherein each fluid end comprises a suction valve assembly configured to direct fluid into the fluid end, and a discharge valve assembly configured to direct fluid out of the fluid end.

10. The frac fluid pumping assembly of claim 9, wherein each fluid end is in fluid communication with a suction manifold and a discharge manifold.

11. The frac fluid pumping assembly of claim 1, wherein the frac fluid pumping assembly further comprises a second pair of hydraulic cylinders that are mechanically decoupled from each other but are hydraulically coupled to each other.

12. The frac fluid pumping assembly of claim 11, wherein the frac fluid pumping assembly further comprises a third pair of hydraulic cylinders that are mechanically decoupled from each other but are hydraulically coupled to each other.

13. A pump system, comprising: a power system;a drive system; andthe frac fluid pumping assembly of claim 1.

14. The pump system of claim 13, wherein the drive system comprises one or more pumps and one or more pump manifolds configured to direct the operating fluid between the pairs of hydraulic cylinders that are hydraulically coupled to each other.

15. The pump system of claim 14, wherein the power system is configured to power the one or more pumps.

16. A frac fluid pumping assembly, comprising: a first hydraulic cylinder comprising a first cylinder housing, a first cylinder rod at least partially disposed within the first cylinder housing, and a first piston coupled to the first cylinder rod and forming a pump side fluid chamber and a plunger side fluid chamber within the first cylinder housing on opposite sides of the first piston;a second hydraulic cylinder comprising a second cylinder housing, a second cylinder rod at least partially disposed within the second cylinder housing, and a second piston coupled to the second cylinder rod and forming a pump side fluid chamber and a plunger side fluid chamber within the second cylinder housing on opposite sides of the second piston; anda pump configured to pump operating fluid into the pump side fluid chamber within the first cylinder housing, and configured to pump operating fluid into the pump side fluid chamber within the second cylinder housing, wherein the plunger side fluid chamber of the first cylinder housing is in fluid communication with the plunger side fluid chamber of the second cylinder housing.

17. The frac fluid pumping assembly of claim 16, wherein the first cylinder rod is coupled to a first plunger that extends into a first fluid end, and wherein the second cylinder rod is coupled to a second plunger that extends into a second fluid end.

18. The frac fluid pumping assembly of claim 17, wherein operating fluid is supplied from the plunger side fluid chamber of the first cylinder housing into the plunger side fluid chamber of the second cylinder housing to move the second piston, the second cylinder rod, and the second plunger in a suction stroke to draw fluid into the second fluid end.

19. The frac fluid pumping assembly of claim 18, wherein operating fluid is supplied from the plunger side fluid chamber of the second cylinder housing back into the plunger side fluid chamber of the first cylinder housing to move the first piston, the first cylinder rod, and the first plunger in a suction stroke to draw fracing fluid into the first fluid end.

20. The frac fluid pumping assembly of claim 19, wherein when the first piston, the first cylinder rod, and the first plunger move in the suction stroke, the second piston, the second cylinder rod, and the second plunger move in a discharge stroke to pump fracing fluid out of the second fluid end.