Reciprocating pump assembly and method thereof

Abstract

A reciprocating pump assembly including a first fluid assembly; a second fluid assembly; and, a power assembly operable by a prime mover. A prime mover including one of an engine and a motor. The power assembly interposed between and shared by the first fluid assembly and the second fluid assembly. The power assembly including at least one rotatable crankshaft operating the first and second fluid assemblies. Also included is a method of pumping fluid for a downhole operation.

What is claimed: 
     
         1 . A reciprocating pump assembly comprising:
 a first fluid assembly;   a second fluid assembly; and,   a power assembly operable by a prime mover including one of an engine and a motor, the power assembly interposed between and shared by the first fluid assembly and the second fluid assembly, the power assembly including at least one rotatable crankshaft operating the first and second fluid assemblies.   
     
     
         2 . The reciprocating pump assembly of  claim 1 , wherein the at least one crankshaft includes a first crankshaft reciprocating a first piston in the first fluid assembly, and a second crankshaft reciprocating a second piston in the second fluid assembly. 
     
     
         3 . The reciprocating pump assembly of  claim 2 , further comprising a pinion shaft rotating the first and second crankshafts. 
     
     
         4 . The reciprocating pump assembly of  claim 3 , wherein longitudinal axes of the first and second crankshafts and the pinion shaft are parallel. 
     
     
         5 . The reciprocating pump assembly of  claim 3 , wherein the pinion shaft includes a pinion gear engaging with a first bull gear on the first crankshaft and a second bull gear on the second crankshaft. 
     
     
         6 . The reciprocating pump assembly of  claim 3 , wherein the power assembly further includes a crankshaft housing enclosing the pinion shaft and both the first and second crankshafts therein. 
     
     
         7 . The reciprocating pump assembly of  claim 2 , wherein the power assembly includes a crankshaft housing enclosing both the first and second crankshafts therein. 
     
     
         8 . The reciprocating pump assembly of  claim 2 , further comprising a first connecting rod connecting the first crankshaft to the first piston and a second connecting rod connecting the second crankshaft to the second piston. 
     
     
         9 . The reciprocating pump assembly of  claim 1 , wherein the at least one crankshaft includes a single crankshaft reciprocating a first piston in the first fluid assembly and reciprocating a second piston in the second fluid assembly. 
     
     
         10 . The reciprocating pump assembly of  claim 9 , further comprising a first connecting rod connecting the single crankshaft to the first piston and a second connecting rod connecting the single crankshaft to the second piston. 
     
     
         11 . The reciprocating pump assembly of  claim 10 , wherein the single crankshaft includes a plurality of eccentrically arranged portions, and the first and second connecting rods are respectively connected to a same portion of the single crankshaft for simultaneously engaging the first and second pistons. 
     
     
         12 . The reciprocating pump assembly of  claim 1 , wherein rotational movement of the at least one crankshaft is converted to linear motion of a first piston in the first fluid assembly, and substantially simultaneously converted to linear motion of a second piston in the second fluid assembly, wherein the linear motion of the first and second pistons is substantially perpendicular to a longitudinal axis of the at least one crankshaft. 
     
     
         13 . The reciprocating pump assembly of  claim 1 , wherein each of the first and second fluid assemblies includes a fluid inlet receiving fluid at a first pressure and a fluid outlet dispensing fluid at a second pressure greater than the first pressure. 
     
     
         14 . The reciprocating pump assembly of  claim 1 , further comprising a first crosshead assembly interposed between the first fluid assembly and the power assembly, and a second crosshead assembly interposed between the second fluid assembly and the power assembly. 
     
     
         15 . The reciprocating pump assembly of  claim 1  wherein the first and second fluid assemblies include first and second pistons, and a longitudinal axis of the at least one crankshaft is perpendicular to a longitudinal axis of the first and second pistons. 
     
     
         16 . The reciprocating pump assembly of  claim 1 , wherein the crankshaft is a direct drive crankshaft and an end of the crankshaft extends beyond a crankshaft housing. 
     
     
         17 . The reciprocating pump assembly of  claim 1 , wherein a plurality of input and output valve pairs of the first and second fluid assemblies are arranged in a direction extending substantially parallel to at least one longitudinal axis of the at least one crankshaft assembly. 
     
     
         18 . A method of pumping fluid for a downhole operation using the reciprocating pump assembly of  claim 1 , the method comprising:
 employing a prime mover to rotate the at least one crankshaft;   moving a first piston in the first fluid assembly via the at least one crankshaft; and,   substantially simultaneously moving a second piston in the second fluid assembly via the at least one crankshaft.   
     
     
         19 . The method of  claim 18 , further comprising directing fluid at a first pressure into first and second inlets of the first and second fluid assemblies, wherein moving the first and second pistons pressurizes the fluid to a second pressure greater than the first pressure. 
     
     
         20 . The method of  claim 18 , wherein employing a prime mover includes connecting a prime mover to the reciprocating pump assembly, the primer mover having a greater horsepower than a prime mover connected to a reciprocating pump assembly having only a first fluid assembly.