Patent Publication Number: US-2022220952-A1

Title: Fracturing pump assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to pumps, and in particular, to an improved fracturing pump assembly. 
     2. Description of the Prior Art 
     Drilling and production systems are often employed to access and extract hydrocarbons from subterranean formations. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly mounted on a well through which the resource is accessed or extracted. These wellhead assemblies may include a wide variety of components, such as various casings, valves, pumps, fluid conduits, and the like, that control drilling or extraction operations. 
     Drilling and production operations, such as fracking, employ fluids referred to as drilling fluids to provide lubrication and cooling of the drill bit, clear away cuttings, and maintain desired hydrostatic pressure during operations. Drilling fluids can include all types of water-based, oil-based, or synthetic-based drilling fluids. Pumps can be used to move large quantities of fluid. Operations come to a halt if the pumps fail, and thus, reliability under harsh conditions, using all types of abrasive fluids, is of utmost commercial interest. Also, portability of these pumps is an issue, so having a versatile pump which can meet the needs of virtually any situation would be desirable. 
     An improved fracturing pump is provided. The pump is reconfigurable on site. Internal components of the pump may be varied to meet the requirements of a specific operation. The reconfiguration gives the user the ability to increase or decrease the horsepower of the pump. A closed loop oil feed system provides constant and reliable lubrication even under heavy loads. The sealing system is enhanced to reduce leaks and thermal stresses. The pump also has an improved frame and chassis to reduce NVH and enhance reliability. 
     SUMMARY OF THE INVENTION 
     It is a major object of the invention to provide an improved fracturing pump assembly. 
     It is another object of the invention to provide a fracturing pump assembly with interchangeable parts. 
     It is another object of the invention to provide a fracturing pump assembly with a variable power output. 
     It is another object of the invention to provide a fracturing pump assembly having an improved frame which utilizes partition support. 
     It is another object of the invention to provide a fracturing pump assembly where the pump frame is integrated into the skid chassis. 
     It is another object of the invention to provide a fracturing pump assembly with a closed loop lubricating system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  generally depicts a wellsite system, in accordance with one or more implementations described herein. 
         FIG. 2  shows a side cutaway view of a prior art pump. 
         FIG. 3  shows a perspective view of a first embodiment of a fracturing pump assembly. 
         FIG. 4  shows a perspective view of a frame and chassis configuration for the pump of  FIG. 3 . 
         FIG. 5 . shows a side cutaway view of a second embodiment of the inventive system using different gearing. 
         FIG. 6  shows a side cutaway view illustrating the pistons and connecting rods. 
         FIG. 7  shows a detail of the fluid handling end. 
         FIG. 8  shows a detail of the bearing assembly. 
         FIG. 9  shows a perspective view of a third embodiment of a fracturing pump assembly. 
         FIG. 10  shows a perspective view of a frame and chassis configuration for the pump of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Generally speaking,  FIG. 1  illustrates a wellsite system in which the inventive fracturing pump can be employed. The wellsite system of  FIG. 1  may be onshore or offshore. In the wellsite system of  FIG. 1 , a borehole  11  may be formed in subsurface formations by rotary drilling using any suitable technique. A drill string  12  may be suspended within the borehole  11  and may have a bottom hole assembly  100  that includes a drill bit  105  at its lower end. A surface system of the wellsite system of  FIG. 1  may include a platform and derrick assembly  10  positioned over the borehole  11 , the platform and derrick assembly  10  including a rotary table  16 , kelly  17 , hook  18  and rotary swivel  19 . The drill string  12  may be rotated by the rotary table  16 , energized by any suitable means, which engages the kelly  17  at the upper end of the drill string  12 . The drill string  12  may be suspended from the hook  18 , attached to a traveling block (not shown), through the kelly  17  and the rotary swivel  19 , which permits rotation of the drill string  12  relative to the hook  18 . A top drive system could alternatively be used, which may be a top drive system well known to those of ordinary skill in the art. 
     In the wellsite system of  FIG. 1 , the surface system may also include drilling fluid  26  (also referred to as fracturing) stored in a pit/tank  27  at the wellsite. A pump  29  supported on a skid  28  may deliver the drilling fluid  26  to the interior of the drill string  12  via a port in the swivel  19 , causing the drilling fluid to flow downwardly through the drill string  12  as indicated by the directional arrow  8 . The drilling fluid  26  may exit the drill string  12  via ports in a drill bit  105 , and circulate upwardly through the annulus region between the outside of the drill string  12  and the wall of the borehole  11 , as indicated by the directional arrows  9 . In this manner, the drilling fluid  26  lubricates the drill bit  105  and carries formation cuttings up to the surface, as the drilling fluid  26  is returned to the pit/tank  27  for recirculation. The drilling fluid  26  also serves to maintain hydrostatic pressure and prevent well collapse. The drilling fluid  26  may also be used for telemetry purposes. A bottom hole assembly  100  of the wellsite system of  FIG. 1  may include logging-while-drilling (LWD) modules  120  and  120 A and/or measuring-while-drilling (MWD) modules  130  and  130 A, a roto-steerable system and motor  150 , and the drill bit  105 . 
       FIG. 2  shows a cutaway side view of a prior art fracturing pump, illustrating various components of the power assembly, the portion of the pump that converts rotational energy into reciprocating motion. A pump as shown in  FIG. 2  could be used as pump  29  of  FIG. 1 , although many other fracturing pumps, including those with designs described below in accordance with certain embodiments of the present technique, could instead be used as pump  29 . Pinion gears  52  along a pinion shaft  48  drive a larger gear referred to as a bull gear  42  (e.g., a helical gear or a herringbone gear), which rotates on a crankshaft  40 . Pinion shaft  48  is turned by a motor (not shown). The crankshaft  40  turns to cause rotational motion of hubs  44  disposed on the crankshaft  40 , each hub  44  being connected to or integrated with a connecting rod  46 . By way of the connecting rods  46 , the rotational motion of the crankshaft  40  (and hub  44  connected thereto) is converted into reciprocating motion. The connecting rods  46  couple to a crosshead  54  (a crosshead block and crosshead extension as shown may be referred to collectively as the crosshead  54  herein). The crosshead  54  moves translationally constrained by guide  57 . Pony rods  60  connect the crosshead  54  to a piston  58 . In the fluid end of the pump, each piston  58  reciprocates to move fracturing in and out of valves in the fluid end of the pump  29 . 
     Referring now to  FIGS. 3 and 4 , it can be seen that the pump  100  has a crankshaft  102 , which drives connecting rods  104 , which ultimately cause reciprocating action of the pistons  106  to create pumping action as in the prior art model discussed above. The pump  100  has an enhanced structural arrangement to increase pump reliability as can be seen most particularly in  FIG. 4 . It can be seen that the pump frame  105 , has a series of partitioning structural dividing walls  107  which serve to separate the rods and pistons but is also configured to reduce NVH and increase pump reliability. In a key aspect of the invention, NVH reduction greatly increases pump reliability by reducing stresses on the pump  100 . The dual chassis skid arrangement  114  is enhanced by adding multiple mounting points (for the pump  100  main body) for increased rigidity and to reduce deflection under load. In a key aspect of the invention, frame  105  and skid  114  are a single integrated structure, which greatly reduces noise, vibration, and harshness (NVH). The reduction in NVH enhances power output significantly. 
     Referring now to  FIGS. 5 and 6  a second embodiment of the pump  200  is shown. It can be seen that the pump  200  has a crankshaft  202 , which drives connecting rods  204 , which ultimately cause reciprocating action of the pistons  206  to create pumping action as in the prior art model, and the previous embodiment discussed above. The pump  100  has the same enhanced structural arrangement to increase pump reliability as discussed above, modified to accommodate the different geometry of the pump  200  versus pump  100 . 
     A closed loop oil feed system  118 , ( 218 ) common to both pumps  100 ,  200  is part of an optimized lubrication system which reduces friction between crosshead  116  ( 216 ) and crosshead guides  117  ( 217 ). Low operating lube oil temperatures and high mechanical efficiency increase reliability. 
     A robust sealing system is provided to improve leak and thermal stresses handling during harsh high temperature fracturing operation in the field. As previously stated, the interior components of the pump, including the plunger  140  ( 240 ), can be interchangeably replaced to increase power output, a key aspect of the invention. In a preferred embodiment power generation for pumps  100 ,  200  range from 3000 HP to 4150 HP by way of interchangeable components. Also, the pumps  100 ,  200  allow variable high pressure output and high flow rate based on variance of plunger size and stroke length. Specifically, an 8 inch stroke creates a horsepower of about 3000 HP, with 9, 10, and 11 inch strokes creating 3400 HP, 3755 HP, and 4150 HP, respectively. (See attached spec sheet for additional details). 
     The enhanced fluid end assembly  123  is shown in  FIG. 7 . The cylindrical bearing assembly  127  is shown in  FIG. 8 . Both the fluid end assembly  123 , and bearing assembly  127  are common to both pumps  100 ,  200 . 
       FIGS. 9 and 10  shows another alternative embodiment of the pump assembly  300 . The assembly  300  is a fracturing pump with gearbox drive horsepower capability that can handle ranges between 3000 Hp to 5000 HP E/T using drive power electric motor or turbine engine E/T based on a gear box ratio between 6.963:1 to 10.50:1 with optimized weight and drive stroke to meet demand for high power, pressure and less equipment. 
     It can be seen that the pump  300  has a crankshaft  302 , which drives connecting rods, which ultimately cause reciprocating action of the pistons to create pumping action as in the prior art model discussed above. The pump  300  has an enhanced structural arrangement to increase pump reliability as can be seen most particularly in  FIG. 10 . It can be seen that the pump frame  305 , has a series of partitioning structural dividing walls  107  which serve to separate the rods and pistons but is also configured to reduce NVH and increase pump reliability. In a key aspect of the invention, NVH reduction greatly increases pump reliability by reducing stresses on the pump  100 . The dual chassis skid arrangement  314  is enhanced by adding multiple mounting points (for the pump  300  main body) for increased rigidity and to reduce deflection under load. In a key aspect of the invention, frame  305  and skid  314  are a single integrated structure, which greatly reduces noise, vibration, and harshness (NVH). The reduction in NVH enhances power output significantly. 
     The pump  300  uses the closed loop oil feed system  118 , ( 218 ) common to pumps  100 ,  200 , which is part of an optimized lubrication system which reduces friction between the crosshead and crosshead guides. Low operating lube oil temperatures and high mechanical efficiency increase long term reliability. 
     It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims: