The present disclosure generally relates to systems and methods for manufacturing reciprocating pumps.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as an admission of any kind.
High-volume, high-pressure pumps are utilized at wellsites for a variety of pumping operations. Such operations may include drilling, cementing, acidizing, water jet cutting, hydraulic fracturing, and other wellsite operations. For example, one or more positive displacement reciprocating pumps may be utilized to pressurize low-pressure fluid from one or more mixers, blenders, and/or other fluid sources for injection into a well.
Each reciprocating pump may include a plurality of reciprocating, fluid-displacing members (e.g., pistons, plungers, diaphragms, etc.) driven by a crankshaft into and out of a fluid-pressurizing chamber to alternatingly draw in, pressurize, and expel fluid from the fluid-pressurizing chamber. Each reciprocating member discharges the fluid from its fluid-pressurizing chamber in an oscillating manner, resulting in suction and discharge valves of the pump alternatingly opening and closing during pumping operations.
Success of pumping operations at a wellsite may be affected by many factors, including efficiency, failure rates, and safety related to operation of the reciprocating pumps. Vibration and repetitive high forces and pressures generated by the reciprocating pumps may cause mechanical fatigue, wear, and/or other damage to the pumps, which may decrease pumping flow rates, quality of downhole operations, and/or operational efficiency.
A summary of certain embodiments described herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure.
Certain embodiments of the present disclosure include a reciprocating pump. The reciprocating pump includes a fluid section including a plurality of fluid-displacing members. Each fluid-displacing member is configured to displace fluid through the reciprocating pump. The reciprocating pump also includes a power section including a plurality of crossheads. Each crosshead is coupled to a respective fluid-displacing member. The power section is configured to actuate the fluid section by actuating the plurality of crossheads through respective crosshead bores formed through the power section. The power section includes a plurality of structural members. The power section also includes a plurality of pairs of support plates. Each pair of support plates is permanently joined to two structural members of the plurality of structural members. Each support plate comprises a precision interior surface. The power section further includes a plurality of pairs of arcuate crosshead guide sections. Each arcuate crosshead guide section is secured in place between two structural members of the plurality of structural members against a respective pair of support plates of the plurality of pairs of support plates. Each pair of arcuate crosshead guide sections includes a top arcuate crosshead guide section and a bottom arcuate crosshead guide section configured to form a portion of a respective crosshead bore.
Various refinements of the features noted above may be undertaken in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. The brief summary presented above is intended to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter.
Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings, in which:
One or more specific embodiments of the present disclosure will be described below. These described embodiments are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
As used herein, the terms “connect,” “connection,” “connected,” “in connection with,” and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element.” Further, the terms “couple,” “coupling,” “coupled,” “coupled together,” and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements.” As used herein, the terms “up” and “down,” “uphole” and “downhole”, “upper” and “lower,” “top” and “bottom,” and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top (e.g., uphole or upper) point and the total depth along the drilling axis being the lowest (e.g., downhole or lower) point, whether the well (e.g., wellbore, borehole) is vertical, horizontal or slanted relative to the surface.
It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for simplicity and clarity, and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.
The present disclosure is directed or otherwise related to structure and operation of a positive displacement reciprocating pump. The pump may be utilized or otherwise implemented for pumping a fluid at an oil and gas wellsite, such as for pumping a fluid into a well. For example, a pump according to one or more aspects of the present disclosure may be utilized or otherwise implemented in association with a well construction system (e.g., a drilling rig) to pump a drilling fluid through a drill string during well drilling operations. A pump according to one or more aspects of the present disclosure may also or instead be utilized or otherwise implemented in association with a well fracturing system to pump a fracturing fluid into a well during well fracturing operations. A pump according to one or more aspects of the present disclosure may also or instead be utilized or otherwise implemented in association with a well cementing system to pump a cement slurry into a well during casing cementing operations. However, a pump according to one or more aspects of the present disclosure may also or instead be utilized or otherwise implemented for performing other pumping operations at an oil and gas wellsite and/or other worksites. For example, a pump according to one or more aspects of the present disclosure may be utilized or otherwise implemented for performing acidizing, chemical injecting, and/or water jet cutting operations. Furthermore, a pump according to one or more aspects of the present disclosure may be utilized or otherwise implemented at mining sites, building construction sites, and/or other work sites at which fluids are pumped at high volumetric rates and/or pressures.
In certain embodiments, the fluid section 104 may include a pump housing 112 having a plurality of fluid-pressurizing chambers 114. One end of each fluid-pressurizing chamber 114 may contain a reciprocating, fluid-displacing member 116 slidably disposed therein and operable to displace a fluid within the corresponding fluid-pressurizing chamber 114. Although the fluid-displacing member 116 is depicted as a plunger, in other embodiments, the fluid-displacing member 116 may instead be implemented as a piston, diaphragm, or other reciprocating, fluid-displacing member.
In certain embodiments, each fluid-pressurizing chamber 114 includes or is fluidly connected with a corresponding fluid inlet cavity 118 configured to communicate fluid from a common fluid inlet 120 (e.g., inlet manifold, suction manifold) into the fluid-pressurizing chamber 114. In certain embodiments, an inlet (i.e., suction) valve 122 may selectively fluidly isolate each fluid-pressurizing chamber 114 from the fluid inlet 120 to selectively control fluid flow from the fluid inlet 120 into each fluid-pressurizing chamber 114. In certain embodiments, each inlet valve 122 may be disposed within a corresponding fluid inlet cavity 118 or otherwise between each fluid inlet cavity 118 and the corresponding fluid-pressurizing chamber 114. In addition, in certain embodiments, each inlet valve 122 may be biased toward a closed-flow position by a spring and/or other biasing means (not shown). In other embodiments, each inlet valve 122 may be actuated to an open-flow position by a predetermined differential pressure between the corresponding fluid-pressurizing chamber 114 and the fluid inlet 120.
In addition, in certain embodiments, each fluid-pressurizing chamber 114 may be fluidly connected with a common fluid outlet 124 (e.g., outlet manifold, discharge manifold). In certain embodiments, the fluid outlet 124 may be or include a fluid cavity extending through the pump housing 112 transverse to the fluid-pressurizing chambers 114. In certain embodiments, an outlet (i.e., discharge) valve 126 may selectively fluidly isolate each fluid-pressurizing chamber 114 from the fluid outlet 124 to selectively control fluid flow from each fluid-pressurizing chamber 114 into the fluid outlet 124. In certain embodiments, each outlet valve 126 may be disposed within the fluid outlet 124 or otherwise between each fluid-pressurizing chamber 114 and the fluid outlet 124. In addition, in certain embodiments, each outlet valve 126 may be biased toward a closed-flow position by a spring and/or other biasing means (not shown). In other embodiments, each outlet valve 126 may be actuated to an open-flow position by a predetermined differential pressure between the corresponding fluid-pressurizing chamber 114 and the fluid outlet 124.
During pumping operations, portions of the power section 102 may rotate in a manner that generates a reciprocating, linear motion to longitudinally oscillate, reciprocate, or otherwise move each fluid-displacing member 116 within the corresponding fluid-pressurizing chamber 114, as indicated by arrows 128. In certain embodiments, each fluid-displacing member 116 alternatingly decreases and increases pressure within each fluid-pressurizing chamber 114, thereby alternatingly receiving (e.g., drawing) fluid into and discharging (e.g., displacing) fluid out of each fluid-pressurizing chamber 114.
In certain embodiments, the crankcase 108 may include a generally circular (e.g., circular with only minor variations, such as manufacturing tolerances from being truly circular) crankcase frame 130, a crankshaft 132, and crankshaft bearings 134 supporting the crankshaft 132 in position within the crankcase frame 130. The prime mover may be operatively connected with (perhaps indirectly) and drive or otherwise rotate the crankshaft 132. In certain embodiments, the crankshaft 132 may include a plurality of crankpins 136 (e.g., offset journals) radially offset from the central axis of the crankshaft 132.
In certain embodiments, the crosshead assemblies 110 may be utilized to transform and transmit the rotational motion of the crankshaft 132 to a reciprocating, linear motion of the fluid-displacing members 116. For example, in certain embodiments, each crosshead assembly 110 may include a connecting rod 138 pivotably (e.g., rotatably) coupled with a corresponding crankpin 136 at one end and with a crosshead 140 of the crosshead assembly 110 at an opposite end. In certain embodiments, an end cap or C-clamp 139 may pivotably couple the connecting rod 138 to the crankpin 136. In certain embodiments, each connecting rod 138 may be pivotably coupled with a corresponding crosshead 140 via a wristpin joint 142. In certain embodiments, the crosshead section 109 may further include a crosshead support frame 144 (i.e., crosshead guide support frame) configured to support and guide sliding motion of each crosshead 140. In certain embodiments, during pumping operations, side walls and upper and lower friction pads of the crosshead support frame 144 may guide or otherwise permit horizontal motion of each crosshead 140 and prevent or inhibit vertical motion of each crosshead 140. In certain embodiments, the crankcase frame 130 and the crosshead support frame 144 may be integrally formed or connected. In certain embodiments, each crosshead 140 may be coupled to a respective fluid-displacing member 116 via a connecting rod 146 (e.g., pony rod). In addition, in certain embodiments, each connecting rod 146 may be coupled with a corresponding crosshead 140 via a threaded connection and with a corresponding fluid-displacing member 116 via a flexible connection. In certain embodiments, the tie-rods 105 may extend through the spacer frame 107 between the crosshead support frame 144 and the pump housing 112 to connect the power and fluid sections 102, 104.
In certain embodiments, a support base 111 may be fixedly connected to the crankcase frame 130 and the crosshead support frame 144. In certain embodiments, the support base 111 may be integrally formed or connected with the crankcase frame 130 and/or with the crosshead support frame 144. In addition, in certain embodiments, the support base 111 may extend along (e.g., underneath) and be fixedly connected (e.g., fastened) with a spacer frame 107. In addition, in certain embodiments, the support base 111 may structurally reinforce the crankcase frame 130, the crosshead support frame 144, and the spacer frame 107. In addition, in certain embodiments, the support base 111 may prevent or inhibit transfer of torque and/or linear forces and, thus, prevent or inhibit relative movement between the crankcase frame 130, the crosshead support frame 144, the spacer frame 107, and the fluid section 104. In addition, in certain embodiments, the support base 111 may be fixedly coupled to a base structure (not shown), such as a skid or mobile trailer, to fixedly connect the pump 100 to the base structure.
In certain embodiments, the pump 100 may be implemented as a triplex pump, which has three fluid-pressurizing chambers 114 and three fluid-displacing members 116. In other embodiments, the pump 100 may instead be implemented as a quintuplex pump having five fluid-pressurizing chambers 114 and five fluid-displacing members 116. In other embodiments, the pump 100 may instead be implemented as a multiplex pump including other quantities of fluid-pressurizing chambers 114 and fluid-displacing members 116.
Conventional positive displacement reciprocating pumps have separate structural components (e.g., a crankcase, a crosshead guide support, a spacer frame, a fluid end) connected in series using fully-threaded tie-rods extending through the structural components. In such conventional systems, the crankcase and the spacer frame nearest the fluid end each have a bottom support, however the crosshead guide support structure is left unsupported other than by compression due to tie-rod tension. This manner of support for a heavily loaded component (e.g., a crosshead guide support) during a forward stroke of the pumping operations is structurally inefficient and tends to have relatively high compliance and lack of rigidity, which can effectively limit the load rating of the overall pump. The embodiments described herein include a structural support system of a positive displacement reciprocating pump, such as the pump 100 illustrated in
The support frame 200 is illustrated in
Conventional positive displacement reciprocating pumps have crosshead guides 158 that are formed by boring a cylindrical hole in a power frame and shrinking a tubular guide into it. However, such designs limit the power end to relatively large center distances and relatively low wrist bearing areas. Other conventional positive displacement reciprocating pumps provide a set of slots between the crosshead bores, and then form cylindrical surfaces on the top and bottom into plates located in window areas. In general, the slots permit full rotation of a boring bar. In such designs, the crosshead bearing surfaces may be secured by bolts, either from the outside or the inside. Other conventional positive displacement reciprocating pumps use a crosshead guide weldment where the full round bore holes overlap without the use of connecting bars. In such designs, jacking devices may be located between the crosshead bores to push the bearing shoes outward from there edges. The embodiments described herein address the shortcomings of these conventional designs.
As described in greater detail herein, after connection of the connecting plate 242 to the outboard and intermediate structural members 210, 230, a relatively large end mill with its axes of rotation aligned generally parallel to a respective crosshead guide 158 may be introduced into a crosshead bore 248 of the respective crosshead guide 158, and used to profile precision interior surfaces of top and bottom support plates 288, 290, which are permanently joined to structural members 210, 230 between pairs of structural members 210, 230, and against which the top and bottom arcuate crosshead guide sections 258, 260 that collectively form the respective crosshead guide 158, and which pair together to form at least a portion of the respective crosshead bore 248 (see, e.g.,
As illustrated, in certain embodiments, each of the outboard and intermediate structural members 210, 230 may include windows 250 therethrough between the crosshead bores 248 to lighten the outboard and intermediate structural members 210, 230. In addition, in certain embodiments, as illustrated in
As described in greater detail herein, during manufacture of the reciprocating pump 100, once the structural members 210, 230 have been aligned generally parallel with each other, the top and bottom support plates 288, 290 have been permanently joined to respective pairs of the structural members 210, 230, and the connecting plate 242 has been connected to the axial ends of the structural members 210, 230, precision interior surfaces of the support plates 288, 290 may be profiled using end mills 286 introduced into the crosshead bores 248 defined by pairs of top and bottom support plates 288, 290.
However, in other embodiments, the support frame 200 may be comprised of a combination of fabricated components (e.g., machined plates, etc.) welded together with pre-cast parts. For example, in certain embodiments, the top and bottom support plates 288, 290 may instead be pre-cast out of an appropriate strength material to define crosshead bores 248 having undersized rough bore dimensions, which may then be machined to post-welded final dimensions, thereby minimizing the amount of machining needed to reach the desired bore dimensions. In addition, in certain embodiments, other features such as the fluid port 278 and associated o-ring seal chamfering may also be included beforehand in the cast parts, further saving time and cost.
The specific embodiments described above have been illustrated by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.
The present document is based on and claims priority to U.S. Provisional Application Serial No.: 63/038,975, filed Jun. 15, 2020, which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2021/037439 | 6/15/2021 | WO |
Number | Date | Country | |
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63038975 | Jun 2020 | US |