FIELD

The present disclosure relates to high pressure reciprocating pumps, and in particular, to a positive displacement reciprocating pump suction manifold auger assembly.

BACKGROUND

High-pressure reciprocating pumps are used in a variety of industrial settings. One use for such pumps is in the oil and gas industry and, specifically to pumps used in completion and stimulation operations including fracturing, cementing, acidizing, gravel packing, snubbing, and similar operations. For example, hydraulic well fracturing treatments are well known and have been widely described in the technical literature dealing with the present state of the art in well drilling, completion, and stimulation operations. Hydraulic fracturing is a process to obtain hydrocarbons such as natural gas and petroleum by injecting a mixture of water, chemicals, and proppant at super high pressure into a wellbore to create cracks in deep rock formations. In a typical hydraulic fracturing operation, the subterranean well strata are subjected to tremendous pressures in order to create fluid pathways to enable an increased flow of oil or gas reserves that may then be brought up to the surface. The fracking fluids are pumped down the wellhead by high-pressure pumps located at the well surface. Examples of such a pump include the SPM QWS 2500 XL and SPM QWS 2500 EXL Frac Pumps manufactured and sold by The Weir Group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are isometric views of a fluid end of an example positive displacement pump outfitted with an embodiment of an auger assembly in the suction manifold according to the teachings of the present disclosure;

FIG. 3 is a front view of a fluid end with a cross-sectional view of the suction manifold outfitted with an embodiment of an auger assembly according to the teachings of the present disclosure; FIGS. 4 and 5 are perspective and front cross-sectional views of a suction manifold equipped with an embodiment of an auger assembly according to the teachings of the present disclosure;

FIG. 6 is a perspective view of the suction manifold providing transparent visibility of an embodiment of an auger assembly according to the teachings of the present disclosure;

FIGS. 7 and 8 are partial cross-sectional views of an embodiment of an auger assembly according to the teachings of the present disclosure;

FIG. 9 is a front cross-sectional view of a suction manifold equipped with another embodiment of an auger assembly according to the teachings of the present disclosure; and

FIG. 10 is a perspective view of a positive displacement pump showing its main components including the suction manifold in which the auger assembly may be installed.

DETAILED DESCRIPTION

Also referred to as a positive displacement pump, high-pressure reciprocating pumps may include one or more plungers driven by a crankshaft to create alternately high and low pressures in a fluid chamber. A positive displacement pump typically has two sections, a power end and a fluid end connected by a plurality of stay rods and tubes that make up a stay rod assembly. The power end includes an internal crankshaft powered by an engine that drives the plungers. The suction manifold of the pump provides the fluid passageway that delivers the fracking fluid to the fluid end of the pump. The fluid end of the pump includes cylinders (not shown) into which the plungers operate to draw fluid into the fluid chamber from the suction manifold (via the log manifold), and then forcibly push out the fluid at high pressure to a discharge manifold. The discharge manifold is connected to a series of flow irons that lead to a well head. In this manner, the reciprocating pump is used to forcefully deliver the fracking fluid at high pressure to the well head and down the well.

A conventional suction manifold for a reciprocating pump is a hollow tubular fluid passageway that does not include any internal structure. A common problem is that proppant (uniform- sized solid particles) in the fracking fluid can accumulate and become lodged and compacted in certain regions of the suction of manifold, such as the drive side bore furthest from the suction manifold inlet. This means that some of the valves and vale seats pass through more of the proppant than others. The uneven proppant distribution results in irregular wear of the valves and valve seats, with the drive side valve and valve seat requiring maintenance before others. The operator thus experiences shortening of the pump maintenance cycle and premature failure of the valves, suction manifold, and other components of the pump.

Referring to FIGS. 1-4, a fluid end 100 of a reciprocating pump is shown coupled to a suction manifold 102 equipped with an auger assembly 110. The auger assembly 110 is installed within the circular bore of the suction manifold 102 to evenly distribute the proppant in the fracking fluid along the length of the suction manifold. The auger assembly 110 includes a helical blade 116 that extends along substantially the entire length of the suction manifold 102. Alternatively, multiple shorter helical blades coupled in series may be used. Referring also to FIGS. 5-8, the helical blade 116 is coupled at each end to circular end supports 120 and 122 that engage the walls of the suction manifold bore. The end supports may have a hub and spoke configuration with an annular rim with a chamfered profile, as shown. Near one end of the suction manifold may include a hard stop 130 in the form of, for example, an annular ridge, against which the annular chamfered rim of the end support 120 abuts. The end supports 120 and 122 and the stop 130 help to maintain the centered placement and alignment of the helical blade 116 within the suction manifold bore. The structural integrity of the auger assembly 110 is further strengthened by the inclusion of one or more support bars 124 that are coupled between the end supports 120 and 122. As shown in the figures, the support bars 124 are positioned and attached equidistantly around the annular rim of the end supports 120 and 122 and span substantially the length of the helical blade. The support bars 124 may be affixed to the outer periphery of the helical blade 116. The use of the support bars 124 adds structural integrity to the auger assembly.

Referring to FIGS. 7 and 8, end support 122 is further coupled to an end cap 132 that removably and sealingly engages the end of the suction manifold bore. The end cap 132 includes a compression pin 134 and a fastener 136 that abut against the end support 122 to keep the auger assembly 110 in its proper position within the suction manifold bore. An O- ring seal 138 may be used at an interface between the compression pin 134 and end cap 132 to seal against leakage of the fluid. A removable clamp 140 is used to secure the end cap 132 to the suction manifold and retain the auger assembly 110 within the bore of the suction manifold.

FIG. 9 shows a cross-sectional view of an alternate embodiment of an auger assembly 900 that includes a helical blade 902 affixed to a center shaft 904. The center shaft 902 is coupled to end supports 906 and 908 that engage the walls of the suction manifold bore and maintain the proper positioning of the helical blade within the suction manifold bore. The center shaft 904 provides the structural integrity and support functionality of the auger assembly 900.

In operation, the helical blade of the auger assembly effectively distributes the proppant in the frack fluid more evenly along the entire length of the suction manifold bore, which results in a more uniform distribution to the fluid chamber of the fluid end via the suction valves and valve seats. The auger assembly may be manufactured with a built-in auger assembly, or it may be retrospectively retrofitted into a suction manifold. In an alternate embodiment, the auger assembly may employ multiple helical blade segments. In another embodiment, a series of spiral blades may be affixed to the wall of the suction manifold bore. In yet another embodiment, an actuator may be coupled to the auger assembly to rotate the helical blade at a predetermined speed to further aid in the distribution of the proppant.

The use of the auger assembly in the suction manifold results in a more uniform distribution of the proppant along the length of the suction manifold and leads to a more even wearing of all the valve and valve seats in the fluid end. The addition of the auger assembly to the suction manifold prolongs the maintenance cycle time period and meaningfully increases the operational runtime of the pump.

FIG. 10 is a perspective view of a positive displacement pump 1000 showing its main components including the suction manifold 1002 in which the auger assembly may be installed. The positive displacement pump 1000 has two sections, a power end 1004 and a fluid end 1006. The fluid end 1006 of the pump includes a fluid end block or fluid cylinder, which is connected to the power end housing via a plurality of stay rods 1008. In operation, the crankshaft (not explicitly shown) reciprocates a plunger rod assembly between the power end 1004 and the fluid end 1006. The crankshaft is powered by an engine or motor (not explicitly shown) that drives a series of plungers (not explicitly shown) to create alternating high and low pressures inside a fluid chamber. The cylinders operate to draw fluid into the fluid chamber via a suction manifold 1010 and then discharge the fluid at a high pressure to a discharge manifold 1012 via a plurality of valves. The discharged liquid is then injected at high pressure into an encased wellbore. The injected fracturing fluid is also commonly called a slurry, which is a mixture of water, proppants (silica sand and/or ceramic), and chemical additives. The pump 1000 can also be used to inject a cement mixture down the wellbore for cementing operations. With the use of the auger assembly in the suction manifold, the solid particles within the fluid is more evenly distributed along the suction manifold to each of the suction valves, resulting in more even wear of the pump components. The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and the novel suction manifold auger assembly described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein.