Abstract
The present invention provides an improved hydraulically activated clamping device for connecting a wellhead and or Christmas tree positioned on a wellhead to a fracing tree that may comprise a connector body; a mandrel body; two or more clamp segments; two or more actuating bolts; a seal ring to provide sealing engagement between said connector body and said mandrel body; one or more motors driving each of said two or more actuating bolts; and control means to reduce or retard the power to the first of said two or more actuating bolts to release and prevent its further movement until the other of said actuating bolts release also.
Claims
1. A connector for connecting oilfield pressure vessels, comprising: a connector body; a mandrel body; two or more clamp segments; two or more actuating bolts; a seal ring to provide sealing engagement between said connector body and said mandrel body; one or more motors driving each of said two or more actuating bolts; a flow divider to a power of a the power to the first of said two or more actuating bolts to release and prevent its further movement until a second of said actuating bolts release also; and means to detect when actuating bolts reach an end of their anticipated movement in a disengagement mode and stopping further movement and thereby allow the second of said actuating bolts to continue their travel until they all reach the end of their anticipated movement and establish A correct relationship again.
Description
BRIEF DESCRIPTION OF THE PICTORIAL ILLUSTRATIONS, GRAPHS, DRAWINGS, AND APPENDICES
(1) The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed pictorial illustrations, graphs, drawings and appendices.
(2) FIG. 1 is generally a perspective view of a pair of valves illustrating a portion of a fracing tree on a pair of valves indicating a portion of a Christmas tree with a connector placed between them in accordance with a preferred embodiment of the current invention.
(3) FIG. 2 is generally a perspective view of connector with its top cover portion of cover removed with the clamp segments in the engaged position in accordance with a preferred embodiment of the current invention.
(4) FIG. 3 is generally a similar perspective view as was seen in FIG. 2 with the clamp segments shown in a released position in accordance with a preferred embodiment of the current invention.
(5) FIG. 4 is generally a section view shown a taken along lines “A-B” of FIG. 5 in accordance with a preferred embodiment of the current invention.
(6) FIG. 5 is generally a top view showing a connector with the top of the cover removed in accordance with a preferred embodiment of the current invention.
(7) FIG. 6 is generally a similar view to FIG. 5 shown with the clamp segments fully open or disengaged such that the upper and lower portions of the connector can be separated in accordance with a preferred embodiment of the current invention.
(8) FIG. 7 is generally a similar view to FIGS. 5 and 6 shown at a step intermediate to that shown in FIG. 5 and FIG. 6 during the makeup or engagement process in accordance with a preferred embodiment of the current invention.
(9) FIG. 8 is generally a view of a clamp segment in an ideal made up condition in accordance with a preferred embodiment of the current invention.
(10) FIG. 9 is generally a view similar to FIG. 8 showing the machine's shape to achieve the shape of FIG. 8 when made up in accordance with a preferred embodiment of the current invention.
(11) FIG. 10 is generally an end view of actuating bolt in accordance with a preferred embodiment of the current invention.
(12) FIG. 11 is generally a section view showing a secondary locking mechanism for an actuating bolt in accordance with a preferred embodiment of the current invention.
(13) FIGS. 12 through 24 are generally other preferred embodiments in accordance with the current invention wherein the actuation is hydraulically actuated cylinders that drive linkages that then move the clamp halves.
DETAILED DESCRIPTION OF INVENTION
(14) Referring to the illustrations, drawings, and pictures, and to FIG. 1 in particular, reference character 10 generally designates a new and improved hydraulically activated connector in accordance with the present invention. Invention 10 is generally used in oil and gas well operations and may be utilized in other operations not associated with oil and gas operations. For purposes of convenience, the reference numeral 10 may generally be utilized for the indication of the invention, portion of the invention, preferred embodiments of the invention and so on. It is also to be understood that invention 10 should not be considered limited to just a “hydraulically activated connector” and the term should not be considered to limit the invention to such.
(15) Referring now to FIG. 1, a portion of the equipment located on the wellhead at a fracing job is generally depicted with two valves 12 and 14 of a Christmas tree 15, two valves 16 and 18 of a fracing tree 19, and a connector 20. The connector is shown with a cover 22, operating valve 24, and hydraulic supply port 26, and hydraulic return port 28.
(16) Referring now to FIG. 2, a perspective view of connector 20 is shown with its top cover portion of cover 22 removed showing top flange 30, clamp segments 32 and 34 in actuated position, actuating bolts 36 and 38, motors 40, 42, 44, and 46, and operating valve 48.
(17) Referring now to FIG. 3, a similar perspective view as was seen in FIG. 2 is shown with the clamp segments 32 and 34 shown in the released position. Actuating bolt 38 is shown with a right hand thread 50 engaging clamp segment 32 and a left hand thread 52 engaging clamp segment 34, so that rotation of actuating bolt 38 in one direction will bring clamp segments 32 and 34 closer together and rotation in the opposite direction will move them away from each other.
(18) Referring now to FIG. 4, a section view is shown taken along lines “A-B” of FIG. 5 showing top flange 30 and bottom flange 60, each of which are shown as standard API bolted flanges but can be clamp hubs or other profiles. Clamp segments 32 and 34 are shown to have protrusions 62, 64, 66 and 68, which engage protrusions 70 and 72 on connector body 74 and protrusions 76 and 78 on mandrel 80.
(19) Connector body 74 may be bolted to the fracing tree 19 and mandrel 80 may be bolted to Christmas tree 15 as seen in FIG. 1. It is understood that connector body 74 and mandrel 80 may be respectively attached to fracing tree and Christmas tree 15 by other means such as but not limited to removable bolts, permanent fixation, welding, and so forth. It is also understood that numerous configurations of bolting may be utilized.
(20) Contact interfaces 82, 84, 86 and 88 are loaded as clamp segments 32 and 34 are moved inwardly to offset the axial loading, which will result from fluid pressure within the bore 90. Pivot pins 92 work with actuating bolts 36 and 38 to bring clamp segments 32 and 34 closer to one another and are supported by retaining rings 94 in slots 96 in cover 22.
(21) Seal ring 100 is provided to seal between connector body 74 and mandrel 80, and is retained in place by connector body bore protector 102, which engages connector body 74 by thread 104, and thereby retains seal ring 100 in place during assembly. Mandrel bore protector 106 is held in place by gravity, as this will characteristically be a vertical connection. The bore 90 the right side of center in FIG. 4 illustrates an assembly where the bore 90 the frac tree 19 and the Christmas tree 15 are the same. The bore 90 the left side of center in FIG. 4 illustrates an assembly where the bore of the frac tree 19 is larger than the bore 90 of the Christmas tree 15.
(22) Referring now to FIG. 5, connector 20 is generally shown from the top view with the top of the cover 22 removed. The top half of the view shows the motors 44 and 46 engaging the ends of actuating bolts 36 and 38. Hex 120 on actuating bolt 38 is intended to be engaged by wrench 122. Cylindrical portion 126 is intended for allowing wrench 124 to be located around it and be disengaged from actuating bolt 38 such that the actuating bolt 38 can be freely operated by motors 42 and 46. Wrench 124 is presently shown in a stowed position and latched in place by appropriate means. Both ends of actuating bolts 36 and 38 have similar profiles and wrenches.
(23) The lower side of FIG. 5 shows operating valve 48 and hydraulic supply connector 130 and hydraulic return connector 132. In the position of operating valve 48 as shown the supply fluid is directed to a flow divider 134 of a positive displacement type such as gear sections and then to the opening side of the motors 40, 42, 44 and 46.
(24) The general purpose of the flow divider 134 is to cause the motors 40, 42, 44 and 46 to run at the same speed so that one actuating bolt does not get ahead of the other and bind the assembly. In addition to that, specifically when the high torque is being released from the actuating bolts at initial breakout, if one starts to move first it will require lower pressure to move and so will accept all the flow, assuring the unit will bind. With positive displacement flow divider 134 in place the opposite will happen, or when one loses its ability of hole pressure due to being released, all the pressure will be directed to the unreleased side assuring it will release also. In this process, they may come to the open position slightly out of timing. If we presume actuating bolt 36 released first and is slightly ahead, when pad 140 on clamp segment 32 hits valve 142, pressure directed from that side of the flow divider 134 will be vented and motors 40 and 44 will be stopped. Motors 42 and 46 will continue until pad 144 on clamp segment 34 hits valve 146 and similar venting occurs. At this time, the actuating bolts 36 and 38 will be properly timed again. For manufacturing convenience, pads 148 and 150 will exist on clamp segment 34 also, but duplicate vent valves will not be required.
(25) In FIG. 5 the clamp segments 32 and 34 are illustrated in the fully made up or engaged position. It is understood that multiple forms of configuration are contemplated and the illustration should not be considered to limit the invention to such.
(26) Referring now to FIG. 6, a similar view to FIG. 5 is shown with the clamp segments 32 and 34 shown fully open or disengaged such that the upper and lower portions of the connector can be separated. Pads 140 and 144 have contacted valves 142 and 146 so the actuating bolts 36 and 38 as well as clamp segments 32 and 34 have been stopped in the desired location.
(27) Referring now to FIG. 7, a similar view to FIGS. 5 and 6 is shown at a step intermediate to that shown in FIG. 5 and FIG. 6 during the makeup or engagement process. At this point, it can be seen that there is more engagement at location 160 and at location 162. It is characteristic in this type of clamp hub engagement that contact is first made at location 160. Contact interfaces 82, 84, 86 and 88 are characteristically at a twenty-five-degree angle of engagement to the plane of movement of clamp segments 32 and 34 so a substantial wedging action occurs at point 160. All engagement force or preloading which is to occur at location 162 may first pass through the wedging action at location 160 to get to location 162. This means that the preloading at location 162 will be reduced by the amount of wedging preloading at location 160, giving highly irregular preloading. In this field, this is often offset by impacting the center back of clamp segments with a sledgehammer to try to drive it to a more uniform loading.
(28) Referring now to FIGS. 8 and 9, two drawings are seen, which look very similar. FIG. 8 shows the radius 170 of the clamp segment 32 as what it will be when made up to the ideal preloading or in other words at the exact same radius as the mating profiles on connector body 74 and mandrel 80. This is not a profile typically achieved on clamp hub designs. FIG. 8 shows how clamp segment 32 is to be machined with radius 172, which is slightly larger than radius 170. By having radius 172 slightly larger than radius 170, engagement will first occur at location 162 of FIG. 7 and clamp segment will effectively be bent to radius 170. In this way, the preload force delivered to location 162 will be the sum of the bending force plus the force passed through the wedging action at location 160. In this way, a simple bolt makeup can result in a highly uniform preload around the circumference of the profiles.
(29) Referring now to FIG. 10, an end view of actuating bolt 38 is shown with right hand thread 50 and left hand thread 52 hex 180 prepared for torque engagement by wrench 124, cylindrical portion 126 to allow for free rotation within wrench 124, and square drive for accepting drive from motor 46. Motor 46 can be of air, hydraulic, or electric style and can be simple direct actuation, impact type actuation, or a combination of the two.
(30) Referring now to FIG. 11, a portion of actuating bolt 36 is shown with a ratchet profile 190 machined around its circumference. Ratchet dog 192 is shown in cylinder 194 and is loaded by spring 196 down into engagement with the ratchet profile 190. Hydraulic connection 198 is connected to the opening circuit of the connector 20 such that when opening pressure is delivered to motors 40, 42, 44 and 46, the ratchet dog 192 is automatically released. The opposite side of cylinder 194 is simply vented as shown at 200. This ratchet mechanism may act as a secondary method of preventing the actuation bolts 36 and 38 from releasing under the vibratory conditions of the fracing operations.
Another Preferred Embodiment
(31) Invention 10 also contemplates that hydraulically actuated cylinders may be utilized instead of torque wrench 124. It is contemplated to change the actuation from being hydraulically powered torque wrenches to hydraulically actuated cylinders that drive linkages that then move the clamp halves. This may allow for the linkages to “lock over center” such that force must be applied to the cylinders for the clamp to be disengaged
(32) The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Changes may be made in the combinations, operations, and arrangements of the various parts and elements described herein without departing from the spirit and scope of the invention. Furthermore, names, titles, headings and general division of the aforementioned are provided for convenience and therefore, should not be considered limiting.
