Mud pump

A mud pump is provided that includes a pump shaft having substantially circular eccentric lobes. Each lobe is rotatably mounted in a connecting rod that, in turn, moves a slide in a horizontal and linearly manner. A pony rod operatively couples a pump fluid end module to one or both sides of each slide frame and a pump fluid end module. As the pump shaft turns, each lobe causes the slide to move side to side. As the slide moves side to side, each pony rod operates a pump fluid end module whose outputs can be coupled to a common manifold.

CROSS REFERENCE TO FOREIGN PRIORITY APPLICATION

This application claims priority under 35 U.S.C. § 119 to Canadian Patent Application No. 3,043,739, entitled “Mud Pump,” filed on May 17, 2019, in the name of Gerald Lesko; which is hereby incorporated by reference for all purposes.

TECHNICAL FIELD OF THE INVENTION

The present disclosure is related to the field of pumps in general and, in particular, pumps used in pumping drilling mud or “mud pumps”.

BACKGROUND OF THE INVENTION

It is known to use pumps to provide drilling mud under pressure in the drilling of wells. Pressurized drilling mud is delivered down a hollow drill string as the well is being drilled to carry away cuttings up the annulus surrounding the drill string to ground level. Such drilling operations are well known to those skilled in the art.

Prior art pumps can use a motor to turn a crankshaft or “pump shaft” to convert rotary motion to a reciprocating motion. The pump shaft moves a connecting rod coupled to a crosshead that moves within a fixed crosshead slide to provide this conversion. The crosshead is coupled to a “pony rod” that provides the pumping motion in a pump fluid end module, as well known to those skilled in the art.

The above-mentioned mechanical arrangement can be multiplied so that a multitude or plurality of pump fluid end modules can be operated from a single pump shaft. The output of each pump fluid end module can be coupled to a common manifold from which pressurized drilling mud can be provided to the drill string. By coupling the pump fluid end module outputs to a common manifold, the pulsing of the pressure of the drilling mud can be reduced or smoothed out, this being a problem well known to those skilled in the art. The disadvantage of this mechanical arrangement is the size and complexity of the components involved to provide a multi-module pump.

It is also known in the oil and gas industry to drill horizontal wells. These are wells that are initially drilled vertically and, with the use of directional drilling equipment as well known to those skilled in the art, the direction of drilled well becomes horizontal or parallel with the ground surface. It is known to drill horizontal wells up to 5486 meters (18000 feet) in length or more. To do so requires the use of “mud motors”, motors that are powered by the delivery of highly pressurized drilling mud pumped through the drill string so as to enable the turning of the drill bit. It is also known that to drill such wells, drilling operators will use at least two or more conventional mud pumps powered by 1000 horsepower or more motors. Each mud pump can be housed in its own pump house and occupies space at the drilling site. As each additional pump house increases the number of structures at a drilling site, the number of truckloads required to deliver the necessary equipment to a drilling site also increases. All this additional equipment and number of truckloads to deliver the equipment add cost to the drilling of the well.

In prior art mud pumps, an example of which is shown inFIG. 1, where bronze plates are used as the bearing surfaces for the horizontal side to side movement of the internal mechanism, an unwanted vertical force applies to the internal mechanism as a result of the crankshaft torque. This can cause undue and accelerated wear and friction on the bronze plates and to the pony rod bushings.

It is, therefore, desirable to provide a pump that can deliver pressurized mud at a volume equivalent to two or more conventional mud pumps without the shortcomings of the prior art technology.

SUMMARY OF THE INVENTION

A pump is provided that comprises a pump shaft having at least one eccentric lobe that is substantially circular. A motor is used to provide the rotational power to the pump shaft. In one embodiment, the motor can be coupled directly to the pump shaft. In another embodiment, a transmission can be used between the motor and the pump shaft to reduce the angular speed of the rotational power provided to the pump shaft. In a representative embodiment, a one or multi-stage transmission can be used as well known to those skilled in the art. In a further embodiment, the motor can be a 3-phase AC motor controlled by a variable frequency drive mechanism to control the speed of the motor.

In one embodiment of the pump, the eccentric lobe can be rotatably disposed within a connecting rod having a substantially circular opening to receive the lobe at one end with the other end rotatably pinned to a slide configured to move in a horizontal and linear manner. In one embodiment, the slide can roll along a support wheel, wherein the wheel ca support the slide to counter the effects of the downward vertical force caused by the crankshaft torque as the slide moves in a linearly and horizontal or side-to-side manner. In one embodiment, the support wheel can be rotatably disposed on an axle coupled to the supporting frame so that the slide can move side-to-side with minimal friction. In another embodiment, the support wheel can roll along a lower track disposed on the bottom of the support frame, wherein the lower track can comprise means for adjusting a loading force on the support wheel against the slide to minimize any gap therebetween so that the slide is constrained to horizontal and linear movement. The support wheel can also center the pony rod in its housing and minimize wear on a wear band deposed therein.

As the lobe rotates within the connecting rod opening, the connecting rod slide can move up and down thereby moving the slide linearly and horizontally along the support wheel. As the slide frame moves side to side, it can move a pony rod in and out to operate a pump fluid end module. By virtue of this configuration, the slide can have a pony rod operatively coupled to one or both opposing sides of the slide. Therefore, a single slide can operate one or two pump fluid end modules at the same time. In a further embodiment, the pump shaft can comprise a plurality of eccentric lobes thereby allowing a plurality of slides to be operated by the lobes and, hence, a plurality of pump fluid end modules to be operated from a single rotating pump shaft.

Broadly stated, in some embodiments, a mud pump is provided, comprising: a frame; at least one pump fluid end module disposed on the frame, the at least one pump fluid end module comprising an inlet port and an outlet port; a pump shaft rotatably disposed in the frame for receiving rotational power from a motor, the pump shaft having at least one substantially circular eccentric lobe disposed thereon, the centre of the at least one eccentric lobe displaced or offset from the longitudinal axis of the pump shaft; at least one slide disposed in the frame, the at least one slide operatively configured to move linearly side-to-side within the frame; at least one pony rod assembly operatively coupling the at least one slide to the at least one pump fluid end module; and a connecting rod comprising first and second ends operatively coupling the pump shaft to the at least one slide, the first end rotatably disposed on the at least one eccentric lobe, the second end rotatably pinned to the at least one slide whereby rotation of the pump shaft causes the slide to move side-to-side that, in turn, causes the at least one pony rod assembly to operate the at least one pump fluid end module; and a support mechanism disposed beneath and operatively coupled to the at least one slide, the support mechanism rotatably coupled to the frame.

Broadly stated, in some embodiments, a mud pump is provided, comprising: a platform; a lattice frame disposed on the platform; at least one pump fluid end module disposed on the frame, the at least one pump fluid end module comprising an inlet port and an outlet port; a pump shaft rotatably disposed in the frame for receiving rotational power from a motor, the pump shaft having at least one substantially circular eccentric lobe disposed thereon, the centre of the at least one eccentric lobe displaced or offset from the longitudinal axis of the pump shaft; a motor operatively coupled to the pump shaft, the motor disposed on the platform; at least one slide disposed in the frame, the at least one slide operatively configured to move linearly side-to-side within the frame; at least one pony rod assembly operatively coupling the at least one slide to the at least one pump fluid end module; and a connecting rod comprising first and second ends operating coupling the pump shaft to the at least one slide, the first end rotatably disposed on the at least one eccentric lobe, the second end rotatably pinned to the at least one slide whereby rotation of the pump shaft causes the slide to move side-to-side that, in turn, causes the at least one pony rod assembly to operate the at least one pump fluid end module; and a support mechanism disposed beneath and operatively coupled to the at least one slide.

Broadly stated, in some embodiments, the support mechanism can comprise a support wheel rotatably disposed beneath the at least one slide, the at least one slide configured to roll along on top of the support wheel.

Broadly stated, in some embodiments, the support wheel can comprise an anti-skidding engagement mechanism.

Broadly stated, in some embodiments, the anti-skidding engagement mechanism can comprise a plurality of anti-skidding balls disposed on one of the support wheel and the at least one slide, and a plurality of corresponding pockets disposed on the other of the support wheel and the at least one slide.

Broadly stated, in some embodiments, the support wheel can be rotatably disposed on an axle operatively coupled to the frame.

Broadly stated, in some embodiments, the plurality of anti-skidding balls can be disposed around a circumference of the support wheel and the plurality of corresponding pockets are disposed along a lower edge of the at least one slide.

Broadly stated, in some embodiments, the support wheel can be rotatably disposed on an adjuster mechanism, the adjuster mechanism comprising a fixed wedge and an overlapping moving wedge, the combination of which can raise or lower the support wheel relative to the at least one slide.

Broadly stated, in some embodiments, the plurality of anti-skidding balls can be disposed along a lower edge of the at least one slide and the plurality of corresponding pockets are disposed around a circumference of the support wheel.

Broadly stated, in some embodiments, the mud pump can further comprise transmission operatively disposed between the motor and the pump shaft thereby coupling the motor to the pump shaft.

Broadly stated, in some embodiments, the transmission can further comprise a single-stage or a multi-stage transmission.

Broadly stated, in some embodiments, the motor can comprise a 3-phase alternating current electric motor.

Broadly stated, in some embodiments, the mud pump can further comprise an intake manifold operatively coupled to the inlet port of the at least one pump fluid end module, the intake manifold providing communication between an intake manifold inlet and the inlet port of the at least one pump fluid end module.

Broadly stated, in some embodiments, the mud pump can further comprise an outlet manifold operatively coupled to the outlet port of the at least one pump fluid end module, the outlet manifold providing communication between the outlet port of the at least one pump fluid end module and an outlet manifold outlet.

Broadly stated, in some embodiments, the at least one pony rod assembly can further comprise: a pony rod support bushing configured to be disposed on the frame; a piston liner comprising first and second ends, the second end operatively coupled to the at least one pump fluid end module; and a pony rod slidably disposed in the support bushing, the pony rod comprising first and second ends, the first end operatively coupled to the at least one slide, the second end further comprising a piston slidably disposed in the piston liner thereby forming a liner chamber disposed between the piston and the support bushing.

Broadly stated, in some embodiments, the pony rod support bushing can further comprise means for circulating coolant and lubricant through the liner chamber.

Broadly stated, in some embodiments, the pony rod support bushing can further comprise means for lubricating the pony rod.

Broadly stated, in some embodiments, the pony rod assembly can further comprise: a pony rod support bushing configured to be disposed on the frame; a stuffing box disposed in the at least one pump fluid end module; and a pony rod slidably disposed in the support bushing, the pony rod comprising first and second ends, the first end operatively coupled to the at least one slide, the second end further comprising a plunger slidably disposed in the stuffing box.

Broadly stated, in some embodiments, the mud pump can further comprise a pump house wherein the mud pump is disposed in the pump house.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 2 to 14, one embodiment of a mud pump is illustrated. In this embodiment, mud pump10can comprise lattice frame18and pump fluid end modules24mounted thereon. Frame18can further comprise mounting tabs14for attaching mud pump10to a platform, to a skid or to a pump house.

For the purposes of this specification, and as shown specifically in the figures, each pump fluid end module24can comprise inlet port25, outlet port35, top access port37(shown as37aand37binFIGS. 6 and 7) and side access port36(shown as36aand36binFIGS. 6 and 7). Pump fluid end module24, as illustrated, can be any suitable pump fluid end module that is readily available to the mud pump industry and is well known to those skilled in the art. As shown inFIG. 2, pump fluid end module24is shown as a singular device having three pump units disposed therein (shown as24ainFIG. 7). It is obvious to those skilled in the art that pump fluid end module24can comprise one or more pump units use in combination. Representative examples of pump fluid end module24are pump fluid end modules having an 800 horsepower rating as manufactured by Continental Emsco in the U.S.A. or their equivalent. Such pumps have interchangeable liners of different diameters whereby the volume of mud handled by a pump fluid end module per pump cycle can be adjusted upwards or downwards depending on the diameter of the liner. Generally speaking, the smaller the volume per pump fluid end module, the greater the pressure the mud can be pumped at.

Referring toFIG. 2, mud pump10is shown having cover20disposed on top of lattice frame18. Input shaft12can be connected to a motor (not shown) to provide rotational input power to mud pump10. In some embodiments, an internal combustion motor can be used to provide rotational input power to mud pump10. In other embodiments, an electric motor of suitable power rating can be used. In further embodiments, a variable frequency drive mechanism (not shown) as well known to those skilled in the art can be used to control the electrical power provided to the electric motor thereby controlling the rotational speed the motor operates at to supply rotational input power to mud pump10.

In one embodiment, mud pump10can comprise transmission22to couple shaft12to the operating components of mud pump10. Transmission22can be a single-stage or multi-stage transmission to reduce the rotational speed of input shaft12to the required rotational speed for proper operation of pump shaft30rotatably disposed in mud pump10. In other embodiments, transmission22can comprise a planetary gear transmission. In further embodiments, transmission22can comprise helical gears. In yet other embodiments, transmission22can comprise spur gears. Intake manifold52, comprising inlet54, is shown attached to pump fluid end module inlet ports25(shown as25aand25binFIGS. 6 and 7). Outlet manifold58, comprising couplers62and end caps66, is shown attached to pump fluid end module outlet ports35.

Referring toFIG. 3, a rear elevation view of mud pump10is shown. In this figure, pony rod support bushings31are shown disposed on sidewalls19of frame18(shown as31aand31binFIGS. 6 and 7).

Referring toFIGS. 4 and 5, front views of mud pump10are shown. In one embodiment, pump fluid end module24can comprise “sucker-cup” pump mechanisms as well known to those skilled in the art. In the illustrated embodiment, an output manifold (not shown) can be attached to the shown outlet ports35to collect drilling mud pumped by pump fluid end module24, in addition to outlet manifold58shown inFIGS. 2 and 3, or it can be capped with a cover (not shown). Input ports25can be coupled together with intake manifold52that directs drilling mud into pump fluid end modules24.

Referring toFIGS. 6 and 7, front cross-section views of mud pump10are shown revealing the internal components of the embodiment shown therein. In this embodiment, pump shaft30rotates as a result of input rotational power applied to input shaft12that is operatively coupled to pump shaft30via transmission22as shown inFIG. 5. In one embodiment, pump shaft30can comprise eccentric80disposed thereon. Rotatably disposed on eccentric80is connecting rod84. In another embodiment, eccentric bearing83is disposed between eccentric80and connecting rod84. In a further embodiment, connecting rod84is rotatably pinned to sidewall28b(and to sidewall28aas shown inFIG. 10) of slide via pin86. In yet another embodiment, bearing85can be disposed between pin86and connecting rod84. Mud pump10can comprise at least one sight glass21to permit visual inspection therein, as shown inFIGS. 2 to 7.

InFIG. 6, eccentric80is shown rotating clockwise thereby moving connecting rod84to the right in this figure. In so doing, slide28is being pushed to the right. In some embodiments, mud pump10can comprise a support mechanism configured for countering the unwanted vertical force as described above and shown inFIG. 1. In some embodiments, the support mechanism can comprise support wheel120disposed beneath slide28whereupon slide28can roll along on top of support wheel120. As shown in more detail inFIGS. 8A and 8B, support wheel120can be comprised of tubular-shaped hub130. As shown inFIGS. 6, 7 and 9 to 14, wheel120can be rotatably disposed on axle126disposed between sidewalls28aand28bof slide28. In some embodiments, bushing124can be disposed between axle126and wheel120as a bearing to minimize friction as wheel120rotates on axle126.

In some embodiments, the support mechanism can comprise an anti-skidding engagement mechanism with slides28. In some embodiments, the anti-skidding engagement mechanism can comprise a plurality of anti-skidding balls122disposed around the circumference of hub130of wheel120in a substantially equally spaced-apart configuration. In some embodiments, wheel120can comprise two such sets of the plurality of anti-skidding balls122, one disposed near each end of hub130. In embodiments, anti-skidding balls122can be comprised of spheres of steel or similarly hard material. In some embodiments, a series of holes136can be drilled through hub130, then a concave pocket can be drilled or machined on the outer surface of hub130at each hole136wherein each of the concave pockets is configured to receive an anti-skidding ball122. Each hole136can then be tapped so as to be able to receive set screws134, in a manner well known to those skilled in the art. Similarly, each anti-skidding ball122can be drilled and tapped to receive a set screw134. In some embodiments, to assemble120, the anti-skidding balls122are placed in the concave pockets disposed on hub130and then secured thereto by set screw134being through hole136into anti-skidding ball122, with each set screw134being tightened so that anti-skidding balls122are secured to hub130. In some embodiments, set screws134can be further secured using a thread-locking liquid, such as Loctite® or similar substance as well known to those skilled in the art. In some embodiments, after anti-skidding balls122have been attached to hub130, bushing124can then be pressed into the interior opening of hub130, in a manner as well known to those skilled in the art.

In some embodiments, one or both of sidewalls28aand28bcan comprise track128disposed along a lower edge thereof, each track128comprising a plurality of substantially equally spaced-apart pockets138(as shown inFIG. 8C) wherein the spacing of pockets138substantially corresponds to the spacing of anti-skidding balls122disposed around wheel120. When slide28is assembled into frame18, pockets138on each track128can be fitted on corresponding anti-skidding balls122on wheel120such that slide28can roll along wheel120in a horizontal linear path from left to right and vice-versa. This configuration can further resist the bending moment caused by the rotation of pump shaft30and eccentric80as wheel120can counter the unwanted vertical force as shown inFIG. 1in the prior art mud pump. In the illustrated embodiment, each of sidewalls28aand28bcomprises a track138for engaging corresponding anti-skidding balls122disposed around a single wheel120. In other embodiments, it is possible that only one of sidewall28aand28bcan comprise a track138, with corresponding anti-skidding balls122disposed around one end of hub130of wheel120. In other embodiments, it possible that more than one support wheel120can be implemented to counter the unwanted vertical force that can be imparted on slide28. In other embodiments, the anti-skidding engagement mechanism can comprise alternate mechanisms for the engagement between slide28and support wheel120, which can comprise but are not limited to straight-cut gear teeth similar to a rack and pinion system as well known to those skilled in the art, angle-cut gear teeth, chain and sprocket profiles disposed onto wheel120and lower edge of slide28, v-shaped profiles disposed onto wheel120and lower edge of slide28, anti-skid elastomeric or rubber material disposed on wheel120and lower edge of slide28, a rail channel disposed on either of wheel120and slide28wherein one of wheel120and slide28can be disposed within the rail channel disposed on the other of wheel120and slide28, as well as any other anti-skidding engagement mechanism as well known to those skilled in the art.

Referring toFIG. 6, as slide28moves to the right, it pushes pony rod27aand, hence, plunger40ato the right in stuffing box26ato push fluids in pump chamber42aout through valve39aoto outlet ports35(not shown) and outlet manifold58(not shown). In so doing, pony rod27balso pulls plunger40bin stuffing box26bto the right thereby drawing in fluid through valve39bifrom intake manifold52.

InFIG. 7, eccentric80is shown rotated further clockwise (fromFIG. 6) thereby moving connecting rod84to the left. In so doing, plunger40ais being pulled to the left thereby drawing in fluid into pump chamber42athrough valve39aifrom intake manifold52while plunger40bis pushed to the left thereby pushing fluid out of pump chamber42bthrough valve39boto outlet ports35(not shown) and outlet manifold58(not shown).

Referring toFIG. 9, mud pump10is shown without pump fluid end modules24, cover22, piston liners26, pump shaft30and connecting rods84. In this illustrated embodiment, frame sidewalls19are visible as are removable caps17, which are configured hold pump shaft30in place in frame18. In some embodiments, retainer caps15can be attached to the outer walls of frame18to further secure removable caps17. With respect to interior walls16, removable caps17can further secured thereto with straps112with threaded fasteners114. With this configuration, caps117can add strength and stiffness to frame18.

Referring toFIG. 10, the mud pump10ofFIG. 9is now shown with frame18removed to reveal slides28. In some embodiments, each slide28can comprise a pair of substantially parallel spaced-apart sidewalls28aand28b, as shown inFIGS. 10 to 14. In some embodiment, each slide28can comprise openings29disposed through sidewalls28aand28bfor pump shaft30(not shown) to pass through and pin boss88disposed through sidewalls28aand28bthat are configured to receive connecting rod pins86.

Referring toFIG. 15A, a cross-section view is shown of a piston embodiment of the internal pumping mechanism of mud pump10. In some embodiments, pony rod27can be coupled to slide28by placing pony rod27into opening91disposed on slide28. In some embodiments, pony rod27can be further secured with pin101disposed on slide28, wherein pin101is configured to fit within opening103disposed in pony rod27to prevent rotation thereof in opening91. In some embodiments, pony rod stud92can be disposed in an opening disposed through pony rod27and secured to slide28in threaded opening93. In some embodiments, pony rod stud92can further comprise flange95that can rest against shoulder94disposed within pony rod27. In some embodiments, piston rod96can be threaded into threaded opening109of pony rod27, wherein rod96can comprise flange105upon which piston40can be secured thereto by nut98threaded onto threaded end107of rod96. Washer97can be sandwiched between nut98and rod96.

In some embodiments, mud pump10can comprise means for circulating coolant in piston liner26behind piston40to prevent overheating of the mechanism when in operation. As shown inFIG. 15A, coolant can be pumped by a coolant pump (not shown) into liner chamber106through coolant inlet102disposed in coupler41via lines, hoses or piping (not shown). Coolant can the flow through, and circulate within, chamber106and then exit through coolant outlet104. Lines, hoses and piping (not shown) can be coupled to outlet104so that the heated coolant can be collected, cooled and re-circulated, all as well known to those skilled in the art. In some embodiments, inlet102and outlet104can further comprise one-way valves, such as ball-valves as one example obvious to those skilled in the art, such that coolant can be drawn into chamber106through inlet102as piston40is moving towards pump fluid end module24(not shown), and then expelled from chamber106through outlet104and piston40is moving away from pump fluid end module24.

In some embodiments, mud pump10can comprise means for circulating lubricating oil to pony rod27as it reciprocates back and forth through support bushing31. As shown inFIG. 15A, with the pump module labelled as24aand piston40slidably disposed in pump chamber42, lubricating oil can be pumped by an oil pump (not shown) into oil inlet108where it can flow into annulus110between pony rod27and support bushing31thereby maintaining a layer of lubricating oil therebetween. Oil can then flow out of annulus110into galleys38(as shown inFIG. 2) where the oil can be collected and re-circulated. In some embodiments, barrier seals99and ice-breaker wear band100can be disposed between pony rod27and support bushing31as sealing means to separate and isolate chamber106from annulus110so that coolant does not intermingle with and contaminate the lubricating oil, and vice-versa.

Referring toFIG. 15B, a cross-section view is shown of a plunger embodiment of the internal pumping mechanism of mud pump10. In some embodiments, pony rod27can be coupled to slide28by placing pony rod27into opening91disposed on slide28. In some embodiments, pony rod27can be further secured with pin101disposed on slide28, wherein pin101is configured to fit within opening103disposed in pony rod27to prevent rotation thereof in opening91. In some embodiments, pony rod stud92can be disposed in an opening disposed through pony rod27and secured to slide28in threaded opening93. In some embodiments, pony rod stud92can further comprise flange95that can rest against shoulder94disposed within pony rod27. In some embodiments, threaded stud221of plunger220can be threaded into threaded opening109of pony rod27. In this embodiment, pump module24bcan comprise stuffing box222disposed in opening223of pump module24b. Stuffing box222can further comprise one or more circumferential seals224disposed therein to seal around plunger220as it reciprocates in and out of stuffing box222.

Referring toFIG. 16, an alternate embodiment of the support mechanism for use with improved mud pump10is shown. In this embodiment, the support mechanism can comprise of support wheel140configured to disposed and roll between upper track142, disposed on a lower surface of slide28, and lower track144, disposed on adjuster mechanism146that is further disposed on bottom plate8. Wheel140can comprise of a similar construction as wheel120, comprising a plurality of anti-skidding balls, as described herein, disposed around the circumference of wheel140and corresponding pockets disposed along upper track142and lower track144. Alternatively, each upper track142and lower track144can comprise anti-skidding balls disposed therealong with corresponding pockets disposed around the circumference of wheel140. To adjust the lash or clearance between wheel140and slide28, adjuster mechanism146can raise or lower wheel140in relation to slide28to minimize the clearance therebetween and to center pony rods27in support bushings31. In some embodiments, adjuster mechanism146can comprise of wedge148and overlapping wedge150, wedge148operatively coupled to adjusting bolt152, wherein lower track144can be disposed on top of wedge150. By turning adjusting bolt152clockwise, as an example, wedge148can move towards to right thereby lifting wedge150to raise lower track144and, thus, wheel140towards upper track142to decrease the lash or clearance therebetween. By turning adjusting bolt152counter-clockwise, as an example, wedge148can move to the left thereby lowering wedge150to lower track144and, thus, wheel140away from upper track142to increase the lash or clearance therebetween.

Referring toFIG. 17, improved mud pump10is shown beside an example of prior art mud pump160having a similar pumping capacity to mud pump10. It is apparent from this comparison that at least one advantage of improved mud pump10is a reduction of size of an equivalent performing mud pump, which can translate into a reduction of cost to an operator in terms of upfront material costs to manufacture the mud pump, a reduction of the cost to maintain the mud pump, a reduction of cost in moving the improved mud pump from site to site, a reduction of costs related to the operation of the mud pump and, at least, a reduction of space required at a site when the improved mud pump is positioned for pumping mud.

In the embodiments illustrated the figures herein, there are three slides28shown, each coupled to two opposing pump fluid end modules24thereby resulting in the operation of six pump fluid end modules. It is obvious to those skilled in the art that fewer or more slides mechanisms can be implemented to either decrease or increase the number of pump fluid end modules that can be operated. As an example, and as shown inFIG. 20, mud pump10can comprise 5 pump fluid end modules24a side, or ten in total. It is also obvious to those skilled in the art that a slide frame can be releasably coupled to a single pony rod to, therefore, operate a single pump fluid end module.

Referring toFIG. 2, mud pump10is shown in a triplex configuration, wherein each side of mud pump10operates three pump fluid end modules24thus requiring pump shaft30to rotate three connecting rods84. This necessarily requires pump shaft30having three eccentric lobes80. In this configuration, the lobes can be displaced nominally 120° apart from each other such that the lobes can be substantially spaced equally apart around the circumference of pump shaft30. In embodiments where pump shaft30comprises two eccentric lobes80, the lobes can be displaced nominally 180° apart. In other embodiments where pump shaft30comprises two lobes80, one lobe80can be displaced 178° from the other lobe80so that pump shaft30can more easily turn from a dead stop. In other embodiments where additional eccentric lobes are disposed on pump shaft30, the lobes can be substantially spaced equally apart on pump shaft30. For example, for a four-lobe shaft, each lobe80can be displaced 90° nominally from each other lobe80. If five lobes are disposed on pump shaft30, the lobes can be displaced nominally 72° apart on pump shaft30, as would be the case for the embodiment of mud pump10shown inFIG. 20. For six lobes disposed on pump shaft30, the lobes can be displaced nominally 60° apart, and so on as well known to those skilled in the art.

In operation, mud can be supplied to inlet54on intake manifold52from an external pump (not shown) drawing mud from a mud tank (not shown) as well known to those skilled in the art. As slides28operate pump fluid end modules24, mud is drawn into pump fluid end modules24from intake manifold52and pumped out of pump fluid end modules24into outlet manifold58via outlet manifold couplers62disposed between pump fluid end modules24and outlet manifold58. The pumped mud can exit outlet manifold58via outlet60that can be connected to a mud delivery pipe and/or hose for use on a drilling rig (not shown) as well known to those skilled in the art. In one embodiment, the diameter of inlet54and the pipe that make up intake manifold52can be nominally ten inches whereas the diameter of outlet and the pipe that make up outlet manifold58can be nominally four inches. In another embodiment, outlet manifold58can comprise couplings (as shown inFIG. 4) for connection with pressure gauge33to provide a visual indication of the pressure of the mud being pumped and/or a pressure relief valve to provide means to limit the pressure of the mud being pumped by mud pump10. It is obvious to those skilled in the art that the diameters of inlet54, intake manifold52, outlet manifold58or outlet60can be increased or decreased depending on the volume and pressure of drilling mud required in the drilling of a well.

In operation, it is expected that mud pump10can operate up to 200 revolutions, which translates up to 400 pump fluid end module strokes per minute per slide frame mechanism given that each slide frame can be coupled to two pump fluid end modules. Given an input power up to 3000 horsepower, it is anticipated that mud pump10can pump up to 750 gallons or 3.75 cubic meters of drilling mud per minute at up to 7500 pounds per square inch of pressure. It is also expected that mud pump10would weigh approximately 45,000 pounds including the motor and all other related equipment required to pump drilling mud at the equivalent volume and pressure of drilling mud as a conventional mud pump powered by the same motor but weighing up to 120,000 pounds.

Referring toFIG. 18, mud pump10is shown positioned in pump house56, a structure used to house mud pumps at drilling sites. Access to mud pump10is done through doorways64. In this configuration, mud pump10can be positioned “lengthwise” in pump house56.

Referring toFIG. 19, mud pump10is shown in pump house56rotated 90 degrees as compared to the embodiment shown inFIG. 18. The compactness of mud pump10can allow it to be installed in this manner in pump house56whereby access to the inlet and outlet to mud pump10is through doorway64. In addition, more than one mud pump10can be installed in pump house56thereby reducing the number of pump houses required at a drilling site if the well being drilled requires a volume of pressurized drilling mud greater than what one mud pump10can provide.

Referring toFIG. 21, another embodiment of a support wheel mechanism can be provided for retro-fitting a conventional mud pump, represented by reference character200. In some embodiments, support wheel208can be rotatably disposed on axle210, further disposed within the body of prior art mud pump200, wherein opening206is made in liner204so as to enable crosshead202to roll along wheel208similar to how slide28can roll along wheel120or wheel140in the embodiments described above. In some embodiments, wheel140can comprise the anti-skidding balls disposed therein, which can be configured to fit within pockets along crosshead202. Alternatively, a plurality of anti-skidding balls can disposed along cross crosshead202with corresponding pockets disposed around the circumference of wheel208.