ISOLATION GAP IN FLUID END DYNAMIC BODY

SUMMARY

[0001]The present invention is directed to a fluid end. The fluid end comprises a dynamic body having a first end and a second end. The dynamic body has at least one internal through-bore extending about a central, longitudinal axis from a first opening at the first end to a second opening at the second end. The dynamic body comprises a first circumferential isolation ring formed at the first end of the dynamic body about the first opening and is concentric about the central, longitudinal axis of the at least one internal through-bore. The fluid end also comprises a static body attached to the dynamic body at the first end.

[0002]In another aspect the present invention is directed to a fluid end. The fluid end comprises a static body having five bores and a dynamic body. The dynamic body has a first surface and a second surface. The dynamic body is attached to the static body at the first surface. The dynamic body has five through-bores extending from the first surface to the second surface, in which the dynamic body is attached to the static body such that each of the five through-bores is aligned with a selected one of the five bores of the static body about a central axis.

[0003]Each of the five through-bores defines a first section, a second section, and an intermediate section. The first section is at a first end of the through-bore and concentric about the central axis. The second section is at a second end of the through-bore and concentric about the central axis. The intermediate section is disposed between the first section and the second section and concentric about the central axis. The intermediate section meets the first section at a first annular shoulder and the second section at a second annular shoulder. The first section is circumscribed by a first isolation ring formed in the first surface of the dynamic body. The first isolation ring is bounded on an inside surface by the through-bore and on an outside surface by a first annular isolation gap formed in the first surface.

[0004]In another aspect, the invention is directed to a dynamic body section for use with a fluid end in a hydraulic fracturing pump. The dynamic body section comprises a body, a first isolation ring, and a second isolation ring. The body has a first side and a second side and at least one through-bore interconnecting the first side and the second side. The at least one through-bore extends about a central axis. The first isolation ring is disposed on the first side of the dynamic body section and concentric about the central axis. The second isolation ring is disposed on the second side of the dynamic body section and concentric about the central axis.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 is an isometric view of a high-pressure pump using one embodiment of a multi-piece fluid end.

[0006]FIG. 2 is an isometric view of the multi-piece fluid end shown in FIG. 1.

[0007]FIG. 3 is a back, top, left isometric view of the multi-piece fluid end shown in FIG. 2.

[0008]FIG. 4 is an isometric view of the dynamic section body of the multi-piece fluid end shown in FIG. 2.

[0009]FIG. 5 is a front elevational view of the dynamic section body shown in FIG. 4.

[0010]FIG. 6 is a back, top, left isometric view of the dynamic section body shown in FIG. 4.

[0011]FIG. 7 is a back elevational view of the dynamic section body shown in FIG. 4.

[0012]FIG. 8 is a cross-sectional view of the dynamic section body shown in FIG. 5, taken along line A-A.

[0013]FIG. 9 is a cross-sectional view of the dynamic section body shown in FIG. 5, taken along line B-B.

[0014]FIG. 10 is an enlarged view of area C in FIG. 8.

[0015]FIG. 11 is an enlarged view of area D in FIG. 8.

[0016]FIG. 12 is a cross-sectional view of the multi-piece fluid end shown in FIG. 2, taken along line E-E.

[0017]FIG. 13 is a cross-sectional view of the multi-piece fluid end shown in FIG. 2, taken along line F-F.

[0018]FIG. 14 is an enlarged view of area G in FIG. 12.

[0019]FIG. 15 is an exploded isometric view of a dynamic section of the multi-piece fluid end shown in FIG. 2.

[0020]FIG. 16 is an enlarged view of area H in FIG. 15.

[0021]FIG. 17 is an exploded, back, top, left isometric view of the dynamic section shown in FIG. 15.

[0022]FIG. 18 is an enlarged view of area I in FIG. 17.

[0023]FIG. 19 is an exploded isometric view of the fluid end body of the multi-piece fluid end shown in FIG. 2.

[0024]FIG. 20 is an exploded isometric view showing the assembly of a flow control system to the fluid end body shown in FIG. 19.

[0025]FIG. 21 is an exploded, back, top, left isometric view showing the assembly of a plunger system to the fluid end body with the assembled flow control systems shown in FIG. 20.

[0026]FIG. 22 is an exploded isometric view showing the assembly of the discharge manifold to the fluid end body with the assembled flow control and plunger systems shown in FIG. 21.

[0027]FIG. 23 is an exploded, back top, right isometric view of the fluid end shown in FIG. 3 showing the assembly of the suction manifold to the fluid end body with the assembled flow control and plunger systems, and discharge manifold shown in FIG. 22.

[0028]FIG. 24 is an exploded isometric view of the high-pressure pump shown in FIG. 1 showing the assembly of the fluid end to the power end.

[0029]FIG. 25 is an exploded back isometric view the high-pressure pump shown in FIG. 1 showing the assembly of the fluid end to the power end.

[0030]FIG. 26 is an isometric view of a high-pressure pump using another embodiment of a multi-piece fluid end.

DETAILED DESCRIPTION

[0031]A high-pressure pump 100 is shown in FIGS. 1, 24, and 25. The high-pressure pump 100 comprises a power end 101, a multi-piece fluid end 102, a plurality of first stay rods 103, a plurality of spacers 104, a plurality of fluid end fasteners 105, and a plurality of pony rod clamps 106. The multi-piece fluid end 102 shown in FIGS. 2, 3, 12, 13, and 23, comprises a fluid end body 107, a plurality of flow control systems 108, a plurality of plunger systems 109, a plurality of discharge manifolds 110, and a plurality of suction manifolds 111. The fluid end body 107, shown in FIG. 19, comprises a static section 112, a dynamic section 113, a plurality of second stay rods 114, and a plurality of body fasteners 115. The dynamic section 113, shown in FIGS. 15-18, comprises a dynamic body 116, a plurality of plunger system wear rings 117, a plurality of plunger system wear ring seals 118, a plurality of plunger system seals 119, a plurality of flow control system wear rings 120, and a plurality of flow control system wear ring seals 121.

[0032]The dynamic body 116, shown in FIGS. 4-11, has the general shape of a rectangular prism. The dynamic body 116 comprises opposing front 122 and back 123 surfaces, opposing top 124 and bottom 125 surfaces, and opposing left 126 and right 127 surfaces. The dynamic body 116 further comprises a plurality of flow bores 128. Each flow bore 128 is a through bore connecting the front 122 and back 123 surfaces. The bore axis of each flow bore 128 is parallel to the transverse axis of the dynamic body 116. In this embodiment there are five flow bores 128 evenly spaced between the left 126 and right 127 surfaces and centered between the top 124 and bottom 125 surfaces.

[0033]Referring now to FIGS. 8, 10, and 11, beginning at the front surface 122 of the dynamic body 116 and moving along the bore axis of the flow bore 128 to the back surface 123, the flow bore 128 comprises a flow control system wear ring section 129, a flow control system wear ring shoulder 130, a flow control system section 131, a plunger section 132, a plunger system shoulder 133, a plunger system section 134, a plunger system wear ring shoulder 135, and a plunger system wear ring section 136. The flow control system wear ring section 129 comprises a seal groove 137 and the plunger system wear ring section 136 comprises a seal groove 138.

[0034]The flow control system wear ring section 129 is tapered, as can be seen in FIG. 10. The largest diameter of the taper is at the front surface 122 and the smallest diameter is at the flow control system wear ring shoulder 130. The taper is complementary to the taper of the outer surface of the flow control system wear ring 120, as shown in FIG. 14.

[0035]Seal groove 137 comprises two side walls 139 connected by a base 140. Each side wall 139 is perpendicular to the bore axis of the flow bore 128 and extends from the tapered surface of the flow control system wear ring section 129 away from the bore axis of the flow bore 128. The base 140 is flat, that is parallel to the bore axis of the flow bore 128. The seal groove 137 is located from the front surface 122 of the dynamic body 116 along the bore axis of the flow bore 128 approximately one-third of the total distance between the front surface 122 and the flow control system wear ring shoulder 130.

[0036]The flow control system wear ring shoulder 130 is formed by the reduction in diameter of the flow bore 128 between the flow control system wear ring section 129 and the flow control system section 131. The flow control system wear ring shoulder 130 is perpendicular to the bore axis of the flow bore 128.

[0037]Referring now to FIG. 8, the flow control system section 131, comprises a straight portion 141, that is the bore wall is parallel to the bore axis of the flow bore 128, and a tapered portion 142. As can be seen in FIGS. 12 and 14 the flow control system section 131 is complementary to the particular components of the flow control system 108 that are inserted within the flow control system section 131.

[0038]The plunger section 132 is also straight and provides a volume for the fluid to enter on the suction stroke of the plunger system 109 and to exit from as the plunger system 109 applies force, generating fluid pressure, on the pressure stroke, as shown in FIGS. 8 and 12.

[0039]The plunger system shoulder 133 is formed by the increase in diameter of the flow bore 128 between the plunger section 132 and plunger system section 134. The plunger system shoulder 133 is perpendicular to the bore axis of the flow bore 128.

[0040]The plunger system section 134 is also straight and complementary to the particular component of the plunger system 109 that is inserted within the plunger system section 134, as shown in FIGS. 8 and 14.

[0041]The plunger system wear ring shoulder 135 is formed by the increase in diameter of the flow bore 128 between the plunger system section 134 and the plunger system wear ring section 136. The plunger system wear ring shoulder 135 is perpendicular to the bore axis of the flow bore 128.

[0042]The plunger system wear ring section 136 is tapered, as can be seen in FIG. 11. The largest diameter of the taper is at the back surface 123 and the smallest diameter is at the plunger system wear ring shoulder 135. The taper is complementary to the taper of the outer surface of the plunger system wear ring 117, as shown in FIG. 14.

[0043]Seal groove 138 comprises two side walls 143 connected by a base 144. Each side wall 143 is perpendicular to the bore axis of the flow bore 128 and extends from the tapered surface of the plunger system wear ring section 136 away from the bore axis of the flow bore 128. The base 144 is flat, that is parallel to the bore axis of the flow bore 128. The seal groove 138 is located from the back surface 123 of the dynamic body 116 along the bore axis of the flow bore 128 approximately one-half of the total distance between the back surface 123 and the plunger system wear ring shoulder 135.

[0044]Referring now to FIGS. 4 and 6, the top surface 124 and bottom surface 125 of the dynamic body 116 each comprise a longitudinal cutout 145. The longitudinal cutouts 145 are identical but mirrored about the transverse axis of the dynamic body 116, for each surface 124 and 125. The features and components of the longitudinal cutout 145 of the top surface 124 will be described with the understanding that every feature and component is present in the longitudinal cutout 145 of the bottom surface 125 and is labeled with the same reference numbers in the figures.

[0045]The longitudinal cutout 145 extends from the left surface 126 to the right surface 127 and comprises a front wall 146, back wall 147, and base 148. The longitudinal cutout 145 further comprises a plurality of support webs 149 that extend between, and connect, the front wall 146 and back wall 147 of the longitudinal cutout 145. The support webs 149 also extend vertically from the base 148. There are five support webs 149 in this embodiment which are aligned with the bore axes of the flow bores 128 on a one-to-one basis. The formation of the longitudinal cutout 145 creates a front flange 150 having a front surface 151 coincident with the front surface 122 of the dynamic body 116 and a back surface 152 coincident with the front wall 146 of the longitudinal cutout 145. In like manner, a back flange 153 is created having a front surface 154 coincident with the back wall 147 of the longitudinal cutout 145 and a back surface 155 coincident with the back surface 123 of the dynamic body 116.

[0046]The front surface 122 of the dynamic body 116 comprises a plurality of second stay rod bores 156. Each second stay rod bore 156 is a threaded blind bore configured to receive a first threaded end 167 of a second stay rod 114. In this embodiment the plurality of second stay rod bores 156 are located in five groups of four with each group centered on a bore axis of one of the plurality of flow bores 128 on a one-to-one basis. As can be seen in FIGS. 4 and 5, each group of four second stay rod bores 156 is distributed symmetrically about the longitudinal and vertical axes centered on each bore axis of the paired flow bore 128.

[0047]The front surface 122 of the dynamic body 116 further comprises a plurality of front isolation gaps 157. Each front isolation gap 157 is a circular groove with a rectangular cross section as shown in FIGS. 4, 5, 8, and 10. The circular groove has a perpendicular central axis. In this embodiment there are five front isolation gaps 157. Each front isolation gap 157 is concentric to a flow bore 128 on a one-to-one basis. Each front isolation gap 157 comprises an inner wall 158 and outer wall 159 connected by a base 160. Each wall 158 and 159 is parallel to the bore axis of the paired flow bore 128 and the base 160 is perpendicular to the bore axis of the paired flow bore 128.

[0048]The front isolation gap 157 creates a ring-shaped section of material, or “front isolation ring” 198, defined between the front isolation gap 157 and the flow bore 128. As shown in FIG. 10 the depth of the front isolation gap 157 from the front surface 122 of the dynamic body 116 is greater than the depth, or length, of the flow control system wear ring section 129 of the flow bore 128 from the front surface 122. Specifically, the front isolation gap 157 extends past the flow control system wear ring shoulder 130.

[0049]The back surface 123 of the dynamic body 116 comprises a plurality of first stay rod bores 161. Each first stay rod bore 161 is a through bore connecting the front 154 and back 155 surfaces of the back flanges 153. Each first stay rod bore 161 is configured to receive a first stay rod 103. In this embodiment the plurality of first stay rod bores 161 are located in five groups of four with each group centered on a bore axis of one of the plurality of flow bores 128 on a one-to-one basis. As can be seen in FIGS. 6 and 7, each group of four first stay rod bores 161 is distributed symmetrically about the longitudinal and vertical axes centered on each bore axis of the paired flow bore 128.

[0050]The back surface 123 of the dynamic body 116 further comprises a plurality of plunger system bores 162. Each plunger system bore 162 is a threaded blind bore configured to receive a threaded end of a component of the plunger system 109. In this embodiment the plurality of plunger system bores 162 are located in five groups of twelve with each group centered on a bore axis of one of the plurality of flow bores 128 on a one-to-one basis. As can be seen in FIGS. 6 and 7, in any one of the five groups each of the twelve plunger system bores 162 is spaced evenly circumferentially at a constant distance from the bore axis of the paired flow bore 128 forming a bolt circle. While it is common for a bolt circle to have the first bolt hole at o-degrees, that is on the vertical axis above the transverse axis, in this embodiment the bolt circle is rotated, or clocked, 15-degrees counterclockwise from the vertical axis.

[0051]The back surface 123 of the dynamic body 116 further comprises a plurality of back isolation gaps 163. Each back isolation gap 163 is a circular groove with a rectangular cross section as shown in FIGS. 6, 7, 8, and 11. In this embodiment there are five back isolation gaps 163. Each back isolation gap 163 is concentric to a flow bore 128 on a one-to-one basis. Each back isolation gap 163 comprises an inner wall 164 and outer wall 165 connected by a base 166. Each wall 164 and 165 is parallel to the bore axis of the paired flow bore 128 and the base 166 is perpendicular to the bore axis of the paired flow bore 128.

[0052]The back isolation gap 163 creates a ring-shaped section of material, or “back isolation ring” 199, defined between the back isolation gap 163 and the flow bore 128. As shown in FIG. 11 the depth of the back isolation gap 163 from the back surface 123 of the dynamic body 116 is greater than the depth, or length, of the plunger system wear ring section 136 of the flow bore 128 from the back surface 123. Specifically, the base 166 of the back isolation gap 163 extends past the plunger system wear ring shoulder 135.

[0053]The assembly procedure of the high-pressure pump 100 is as follows: Referring now to FIGS. 14-16, the dynamic section 113 is assembled by first, inserting the flow control system wear ring seal 121 into the seal groove 137 of the flow control system wear ring section 129 of the flow bore 128. Second, inserting the flow control system wear ring 120 into the flow control system wear ring section 129 of the flow bore 128 with the flow control system wear ring 120 oriented such that the tapered surfaces match. The tapered surfaces are an interference fit with the amount of insertion controlled by the flow control system wear ring 120 contacting the flow control system wear ring shoulder 130.

[0054]Referring now to FIGS. 14, 17, and 18, the third assembly step for the dynamic section 113 is to insert the plunger system wear ring seal 118 in the seal groove 138 of the plunger system wear ring section 136 of the flow bore 128. Second, the plunger system wear ring 117 is inserted into the plunger system wear ring section 136 of the flow bore 128 with the plunger system wear ring 117 oriented such that the tapered surfaces match. The tapered surfaces are an interference fit with the amount of insertion controlled by the plunger system wear ring 117 contacting the plunger system wear ring shoulder 135. Fourth, the plunger system seal 119 is inserted in the plunger system wear ring 117. The insertion depth of the plunger system seal 119 is also controlled by the plunger system wear ring shoulder 135. This completes the assembly of the dynamic section 113 of the fluid end body 107.

[0055]Referring now to FIGS. 13 and 19, the fluid end body 107 is assembled by attaching the static section 112 to the dynamic section 113 using the plurality of second stay rods 114 and the plurality of body fasteners 115. A first threaded end 167 of each second stay rod 114 is threaded into a corresponding second stay rod bore 156 and torqued to specification. Second, the second stay rod bores 168 of the static section 112 are aligned with the second stay rods 114 now protruding from the front surface 122 of the dynamic body 116 and the static section 112 is abutted to the dynamic section 113 while simultaneously inserting the second stay rods 114 into the second stay rod bores 168. The plurality of body fasteners 115 are threaded onto the second threaded ends 169 of each of the plurality of second stay rods 114 on a one-to-one basis. This completes the assembly of the fluid end body 107.

[0056]Referring now to FIGS. 12, 14, and 20, the multi-piece fluid end 102 is assembled by first installing the plurality of fluid control systems 108 into the plurality of flow bores 170 of the multi-piece fluid end 102 on a one-to-one basis. Each flow bore 170 of the multi-piece fluid end 102 comprises the flow bore 128 of the dynamic body 116 and the flow bore 171 of the static section 112. As can be seen in FIG. 14 each flow control system 108 engages each flow control system wear ring 120 which provides a sealing surface and a locating surface for the flow control system 108.

[0057]Referring now to FIGS. 12, 14, and 21, the plurality of plunger systems 109 are installed in the plurality of flow bores 128 of the dynamic body 116 on a one-to-one basis. As can be seen in FIG. 14 each plunger system 109 engages each plunger system section 134 which provides concentric alignment with the flow bore 128 for the plunger system 109. Each plunger system 109 also engages each plunger system seal 119 keeping fluid from leaking between the plunger system 109 and the dynamic body 116. Each plunger system 109 also abuts each plunger system wear ring 117 which, along with the back surface 123 of the dynamic body 116 controls how far the plunger system 109 is inserted into the flow bore 128.

[0058]Referring now to FIGS. 13 and 22, the plurality of discharge manifolds 110 are attached to the static section 112. Detailed descriptions of the discharge manifold 110 and its installation are found in the above referenced documents.

[0059]Referring now to FIGS. 13 and 23, the plurality of suction manifolds 111 are attached to the static section 112. Detailed descriptions of the suction manifold 111 and its installation are found in the above referenced documents. This completes the assembly of the multi-piece fluid end 102.

[0060]Referring now to FIGS. 24-25, the high-pressure pump 100 is assembled by attaching the multi-piece fluid end 102 to the power end 101 using the plurality of first stay rods 103, plurality of spacers 104, plurality of fluid end fasteners 105, and plurality of pony rod clamps 106. A detailed description of the components and assembly procedure is provided in the above referenced documents.

[0061]In operation the front isolation gap 157 creates a fixed radial distance between the bore wall of the flow control system wear ring section 129 of the flow bore 128 and the inner wall 158 of the front isolation gap 157. This fixed radial distance between the two surfaces results in a constant thickness of the front isolation ring 198 between the two surfaces. Since the material has a constant thickness, the outward radial forces produced by the high-pressure fluid within the flow bore 128 produce an equal deflection in every radial direction. This equal deflection eliminates stress variations within the flow control system wear ring 120 increasing the life of the flow control system wear ring 120 and reducing the likelihood of fluid leaking past either the flow control system wear ring seal 121 or the flow control system 108. In the same manner, the back isolation gap 163 creates the back isolation ring 199, increasing the life of the plunger system wear ring 117 and reducing the likelihood of fluid leaking past either the plunger system wear ring seal 118 or the plunger system seal 119.

[0062]Without the isolation gaps 157 and 163, the radial distance between the bore wall of the flow bore 128, specifically the flow control system wear ring section 129 and plunger system wear ring section 136, and the surface of the dynamic body 116 will necessarily be different at any circumferential point of the flow bore 128 due to the rectilinear shape of the dynamic body 116 and the circular shape of the flow bore 128. These different radial distances result in different material thicknesses and different radial deflections at every circumferential point around the flow bore 128. The different deflections increase the likelihood that fluid will leak internally or externally around the wear rings 117 and 120. The different deflections also result in different stresses around the circumference of the wear rings 117 and 120.

[0063]These differing stresses reduce the life of the wear rings 117 and 120. The isolation gaps 157 and 163 eliminate these problems by creating isolation ring sections 198 and 199 of even thickness about the flow control system wear ring section 129 and plunger system section 134, respectively.

[0064]Another embodiment of a high-pressure pump 200 is shown in FIG. 26. High-pressure pump 200 comprises another embodiment of discharge manifold 210. Discharge manifold 210 is comprised of traditional ‘frac iron’ fittings well known in the industry. High-pressure pump 200 may be identical to high-pressure pump 100 with the exception of the discharge manifold 210.

[0065]While the sections of the flow bore 128 have been described exhaustively, some details of the flow bore 128 were omitted for brevity. Such details may include the transition areas between each section of the flow bore 128 which may include radii and/or chamfers as needed to reduce stress concentrations due to the changes in diameter along the flow bore 128.

[0066]In the disclosed embodiments the isolation gaps 157 and 163 have a constant width, straight side walls, and a flat base. Any of these features may be altered to allow for design and or fabrication considerations. Also, the depth of the isolation gaps is as deep as the section of the flow bore within which the affected component, namely the wear ring, is installed. The depth may be greater or lesser if required. A lesser depth may reduce the effectiveness of the isolation gap but still provide a benefit. Additionally, the flow bore and isolation gap in the described embodiments are circular, they may be of any cross-sectional shape and still derive the benefit of having a constant material thickness due to an isolation gap. It is also contemplated that isolation gaps be added to existing fluid ends as a retrofit improvement.

[0067]The various features and alternative details of construction of the apparatuses described herein for the practice of the present technology will readily occur to the skilled artisan in view of the foregoing discussion, and it is to be understood that even though numerous characteristics and advantages of various embodiments of the present technology have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the technology, this detailed description is illustrative only, and changes may be made in detail, especially in matters of structure and arrangements of parts within the principles of the present technology to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.