TITLE: MUD PUMP

INVENTOR:

Gerald Lesko

CROSS-REFERENCE TO RELATED APPLICATIONS: This application claims priority from U.S. Provisional Patent Application No.

60/992778 filed December 6, 2007. TECHNICAL FIELD:

The present disclosure is related to the field of pumps, in particular, pumps used in pumping drilling mud or "mud pumps". BACKGROUND:

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 "eccentric shaft" to convert rotary motion to a reciprocating motion. The eccentric 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, in turn, is coupled to a piston rod that provides the pumping motion in a pump 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 modules can be operated from a single eccentric shaft. The outputs of each pump module can be coupled to a common manifold from which

{E5543286.DOC;1}

pressurized drilling mud can be provided to the drill string. By coupling the pump 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 5000 to 7500 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 is 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.

It is, therefore, desirable to provide a pump that can convert rotary motion to reciprocating motion without having to use connecting rods, crossheads, crosshead slides and pony rods to reduce its size, complexity and cost to manufacture. It is also desirable to provide a mud pump that is compact in size but can deliver pressurized mud at a volume equivalent to two or more conventional mud pumps.

{E5543286.DOC;-!}

SUMMARY:

A pump is provided that comprises an eccentric shaft having at least one eccentric lobe that is substantially circular. A motor is used to provide the rotational power to the eccentric shaft. In one embodiment, the motor can be coupled directly to the eccentric shaft. In another embodiment, a transmission can be used between the motor and the eccentric shaft to reduce the angular speed of the rotational power provided to the eccentric shaft. In a representative embodiment, a one or two-stage planetary gear transmission can be used. 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 slide having a substantially circular opening to receive the lobe. The slide can be slidably disposed within a slide frame that allows the slide to move up and down within the slide frame. In one embodiment, bearing mechanisms are disposed on both the left and right sides of the slide within the slide frame so that the slide can move up and down within the slide frame with minimal friction. In a representative embodiment, the bearing mechanism can further comprise v-shaped rollers moving on v-shaped guide tracks disposed on each side of the slide frame.

As the lobe rotates within the slide opening, the slide can move up and down within the slide frame. In addition, the slide will also move side to side thereby causing the slide frame to move side to side. As the slide frame moves side to side, it can move a piston rod in and out to operate a pump module. By virtue of this configuration, the slide frame can have a piston rod operatively coupled to one or both opposing sides of

{E5543286.DOC;-!}

the slide frame. Therefore, a single slide frame can operate one or two pump modules at the same time. In a further embodiment, the eccentric shaft can comprise a plurality of eccentric lobes thereby allowing a plurality of slide frames to be operated by the lobes and, hence, a plurality of pump modules to be operated from a single rotating eccentric shaft.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 is a front perspective view depicting a mud pump having two slide frame mechanisms operating four pump modules.

Figure 2 is a top plan view depicting the mud pump of Figure 1 with the slide frame cover removed.

Figure 3 is a side elevational view depicting the mud pump of Figure 1.

Figure 4 is a rear perspective view depicting the mud pump of Figure 1.

Figure 5 is a front elevational view depicting the mud pump of Figure 1 with the motor removed. Figure 6 is a front perspective view depicting the mud pump of Figure 1 with the motor, slide frame cover and pump frame removed.

Figure 7 is a front perspective view depicting the mud pump of Figure 6 with one slide frame removed.

Figure 8 is a front perspective sectional view of the mud pump of Figure 6. Figure 9 is a front elevational view of the mud pump of Figure 8.

Figure 10 is a perspective view of an eccentric shaft having two eccentric lobes.

Figure 11 is a perspective view depicting a mud pump having three slide frame mechanisms operating six pump modules.

{E5543286.DOC;-!}

Figure 12 is a perspective view depicting the mud pump of Figure 11 installed in a pump house.

Figure 13 is a perspective view depicting the mud pump of Figure 11 installed in a pump house. DETAILED DESCRIPTION OF EMBODIMENTS

Referring to Figures 1 to 9, one embodiment of a mud pump is illustrated. In this embodiment, mud pump 10 can comprise motor 12 mounted on platform 16 via motor mounts 14. Platform 16 can further comprise lattice frame 18 and pump modules 24 mounted thereon. In another embodiment, platform 16 can further integrally comprise a tank or vessel for holding fluids such as coolants or lubricants.

For the purposes of this specification, and as shown specifically in Figure 9, each pump module 24 can comprise inlet port 25, outlet port 35, top access port 37, side access port 36 and valve recesses 33 for holding a pump valve mechanism (not shown). Pump module 24, as illustrated, can be any suitable pump module that is readily available to the mud pump industry and is well known to those skilled in the art. Representative examples of pump module 24 are pump 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 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 module, the greater the pressure the mud can be pumped at.

Referring to Figure 1 , mud pump 10 is shown having slide frame cover 20 disposed on top of lattice frame 18. Referring to Figure 2, a top plan view of mud pump

{E5543286.DOC;"!}

10 is shown with cover 20 removed. In this embodiment, motor 12 can be coupled to transmission 22. Transmission 22 can be a single-stage or a dual-stage planetary gear transmission to provide the necessary gear reduction of the motor speed of motor 12 to produce the desired rotational speed of eccentric shaft 30. Eccentric shaft 30 passes through lattice frame 18 and slides 28. Each slide 28 is disposed within slide frame 29 having rollers 34 rotatably disposed between slide 28 and slide frame 29 on each side of slide 28. On either side of slide frame 29, piston rod 26 can be releasably attached whereby each piston rod 26 can pass through a corresponding piston rod guide 31 to operate pump mechanism 32 attached to pump module 24. In one embodiment, pump mechanism 32 can comprise a "sucker-cup" pump mechanism as well known to those skilled in the art. 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 motor 12 thereby controlling the rotational speed motor 12 operates at. In this illustrated embodiment, there are two slide frames 29 shown, each coupled to two pump modules 24 thereby resulting in the operation of four pump modules. It is obvious to those skilled in the art that fewer or more slide frame mechanisms can be implemented to either decrease or increase the number of pump modules that can be operated. It is also obvious to those skilled in the art that a slide frame can be releasably coupled to a single piston rod to, therefore, operate a single pump module.

Referring to Figures 3 and 4, a side view of mud pump 10 is shown. In this embodiment, pump modules 24 are shown with outlet ports 35 exposed having no

{E5543286.DOC;1}

output manifold attached thereon. In operation, an output manifold (not shown) would be attached to outlet ports 35 to collect drilling mud pumped by pump module 24. Pump module access ports 36 are shown with covers removed. In operation, these access ports 36 would be covered to seal off pump module 24. In this embodiment, access port 36 can be exposed to access piston rod 26 so as to releasably engage or disengage piston rod 26 from slide frame 29 to connect or disconnect pump module 24. Referring to Figure 5, a front-end view of mud pump 10 is shown. In this illustration, the cover of transmission 22 is removed to show an embodiment of a planetary gear transmission suitable for use with mud pump 10. Referring to Figure 6, a perspective view of mud pump 10 is shown with lattice frame 18 and platform 16 removed. Referring to Figure 7, a single slide frame 29 has been removed to reveal slide 28 disposed therein. In this illustration, rollers 34 can be seen with greater clarity rotatably attached to slide 28. Also shown is roller guide 40 upon which rollers 34 contact and roll against for directional guidance. Eccentric flange 38 is also shown. In this embodiment, eccentric flange 38 is mounted on lattice frame 18 and provides support for eccentric shaft 30 as it passes through slides 28.

Referring to Figures 8 and 9, a cut away section of mud pump 10 is shown. In this illustration, each slide 28 can comprise an eccentric lobe bearing 42 disposed therein to receive an eccentric lobe 44 of eccentric shaft 30. Referring to Figure 9, an eccentric lobe 44 is shown rotating in a clockwise direction. As shown in this embodiment, eccentric lobe 44 can be a substantially circular member whose centre can be displaced or offset from the longitudinal axis of eccentric shaft 30. As lobe 44 rotates in this direction, slide 28 moves upwards within

{E5543286.DOC;-!}

slide frame 29. In addition, slide frame 29 moves to the left, as shown in this illustration. In doing so, slide 29 pushes piston rod 26A towards pump module 24A whereby pump mechanism 32A is pushing drilling mud in pump module 24A out through outlet port 35A. Conversely, as slide frame 29 moves towards the left, it is drawing with it piston rod 26B. In doing so, pump mechanism 32B is drawing in drilling mud into pump module 24B through inlet port 25B.

Referring to Figure 10, an embodiment of an eccentric shaft 30 is shown. In this embodiment, eccentric shaft 30 is shown having two eccentric lobes 44. In this configuration, the lobes can be displaced nominally 180° apart from each other. In a representative embodiment, one lobe 44 can be displaced 178° from the other lobe 44 so that eccentric shaft 30 can more easily turn from a dead stop. In other embodiments where additional eccentric lobes 44 are disposed on eccentric shaft 30, the lobes can be substantially spaced equally apart on eccentric shaft 30. For example, for a three- lobe shaft, each lobe 44 can be displaced 120° nominally from each other lobe 44. If four lobes are disposed on shaft 30, the lobes can be displaced nominally 90° apart on an eccentric shaft 30 and so on.

Referring to Figure 11 , an alternate embodiment of the mud pump described herein is shown having three slide frame mechanisms operating six pump modules. In this embodiment, mud pump 50 can comprises frame 18 further comprising three slide frames 29 operating six pump modules 24. The inlet port of each pump module 24 can connect to intake manifold 52 via its own intake manifold coupler 56. Mud can enter intake manifold 52 through inlet 54. Mud can be supplied to inlet 54 from an external pump (not shown) drawing mud from a mud tank (not shown) as well known to those

{E5543286.DOC;1}

skilled in the art. As slide frames 29 operate pump modules 24, mud is drawn into pump modules 24 from intake manifold 52 and pumped out of pump modules 24 into outlet manifold 58 via outlet manifold couplers 62 disposed between pump modules 24 and outlet manifold 58. The pumped mud can exit outlet manifold 58 via outlet 60 that 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 inlet 54 and the pipe that make up intake manifold 52 can be nominally ten inches whereas the diameter of outlet 60 and the pipe that make up outlet manifold 58 can be nominally four inches. In another embodiment, outlet manifold 58 can comprise couplings 64 for connection with a pressure gauge to 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 pump 50. It is obvious to those skilled in the art that the diameters of inlet 54, intake manifold 52, outlet manifold 58 or outlet 60 can 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 pump 50 can operate up to 65 revolutions per minute using a 1000 horsepower motor, which translates up to 130 pump module strokes per minute per slide frame mechanism given that each slide frame can be coupled to two pump modules. It is also anticipated that mud pump 50 can pump up to 800 gallons or 4 cubic metres of drilling mud per minute. Using 7-inch liners in the pump modules, it is expected that mud pump 50 can pump mud up to 1500 pounds per square inch in pressure. It is also expected that mud pump 50 would weigh approximately 45,000 pounds and deliver the equivalent volume and pressure of drilling

{E5543286.DOC;!}

mud as a conventional mud pump powered by a 1600 horsepower motor weighing up to 120,000 pounds.

Referring to Figure 12, mud pump 50 is shown positioned in pump house 68, a structure used to house mud pumps at drilling sites. Access to mud pump 50 is done through doorways 70. In this configuration, mud pump 50 is positioned "lengthwise" in pump house 68. Referring to Figure 13, mud pump 50 is shown in pump house 68 rotated 90 degrees. The compactness of mud pump 50 can allow it to be installed in this manner in pump house 68 whereby access to the inlet and outlet to mud pump 50 is through doorway 70. In addition, more than one mud pump 50 can be installed in pump house 68 thereby 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 pump 50 can provide.

Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow.

{E5543286.DOC;-!}