The present invention relates to connecting components. More specifically, the present invention provides an apparatus and method to connect two parts without rotating either of the parts in a string assembly.
In many oilfield related operations it can be desirable or necessary to form a connection between parts without rotating either. For example, in coiled tubing operations, a coiled tubing string is connected to a bottomhole assembly (BHA) which typically includes tools such as those needed for stimulating, fracturing, drilling, etc. In coiled tubing operations, the coiled tubing string is advanced into the well or withdrawn from the well using a coiled tubing injector head, as is known in the art. It is often necessary to connect the BHA which is fixed and cannot rotate (due to length/weight or being in a closed BOP ram) to the bottom of the coiled tubing which is hanging below the lubricator and is also unable to rotate.
There is, therefore, a need for a connector suitable for operations which does not require high levels of torque to make the connection yet which is able to transmit the torque encountered in across the joint.
An embodiment of the present invention provides connector for connecting two parts without rotating either of the two parts. The connector comprises a first part with N engagement members; a second part with N+1 engagement members; and a sleeve having a first and second end, the first end having N engagement members for engaging the N engagement members of the first part, the second end having N+1 engagement members for engaging the N+1 engagement members of the second end.
Another embodiment of the present invention provides a connector for connecting two parts without rotating either of the two parts, the connector comprising a first part with N engagement members; a second part with N−1 engagement members; and a sleeve having a first and second end, the first end having N engagement members for engaging the N engagement members of the first part, the second end having N−1 engagement members for engaging the N−1 engagement members of the second end.
Yet another embodiment of the present invention provides a connector to connect two parts without rotating either of said two parts, the connector comprising a first part having a set of distal engagement members on a distal end; a second part having a bore in a proximal end to receive the distal end of the first part, the proximal end of the second part having a set or proximal engagement members; and a first sleeve having a set proximal engagement members on a proximal end to engage with the set of distal engagement members of the first part and a set of distal engagement members on a distal end to engage with the set of proximal engagement members of the second part.
Still another embodiment of the present invention provides a method to connect two parts without rotating either of said two parts, the method comprising inserting a distal end of a first part axially into a bore in a proximal end of a second part; engaging a set of proximal engagement members on a proximal end of a first sleeve with a set of engagement members on the first part and a set of distal engagement members on a distal end of the first sleeve with a set of engagement members on the proximal end of the second part; and retaining the first sleeve to at least one of the first part and the second part.
It should be understood that although the connection apparatus and method are described primarily with reference to downhole components, the tool has equal application to the connection of non-rotatable components in large rotary equipment, generators, coiled tubing injector connectors, large equipment axles, and the like. Accordingly, the terms proximal and distal used in describing the connection tool used in a downhole environment, can be replaced with upper/lower, left/right, 1st/2nd, etc., depending upon the application, orientation, or environment. Although rotation can be used to connect either end of a disconnected component of a connector (e.g., a mandrel and sub), the non-rotation of the two components forming the actual joint is the reason for the present application.
The present invention provides a connector that allows connection of two parts without relative rotation between the two parts and yet preserves the ability for the transmission of torque across the connection. The connector can preserve the full strength of the assembly with minimal backlash. Additionally, the connection tool utilizes a removable engagement sleeve to prevent damage to the engagement members during the stabbing process and allows easy replacement and/or dressing of damaged engagement members. Although the terms proximal and distal are used to recite spatial relationship of the components, the connector of the present invention can be used in any orientation.
In general, the connector of the present invention comprises components having mating engagement members. In the examples shown, the engagement members are castellations or splines but it should be understood that alternate types of mating elements such as teeth, protrusions, extensible members, etc., can be used to advantage by the present invention. In a particular embodiment, a first element has N engagement members, a second element has N+1 engagement members and a third element has N and N+1 engagement members to mate with the first and second elements. It should be understood that the first element (and likewise the second element) can act as either the proximal or the distal end of the assembled connection.
One embodiment of a connector 100 of the present invention is illustrated in
In the embodiment shown, the connector 100 includes an engagement sleeve 120, a first element 160, second element 180, and a retention sleeve 140. The engagement sleeve 120 has engagement members 122 and 124 on the proximal and distal ends thereof. In the embodiment shown, the engagement members 122 on the proximal end are circumferentially spaced splines 122 and the engagement members 124 on the distal end are a set of castellations 124. It should be understood that the engagement members 122, 124 are not so limited to splines and castellations and the type and location of the engagement members is only limited to the orientation that is necessary to mate with engagement members on the first element 160 and the second element 180.
As shown more clearly in
Referring to
The distal section 166 of the first element 160 can then be axially disposed into the bore 185 in the proximal end 107 of the second element 180. To restrict relative rotation between the second element 180 and the first element 160 (e.g., for transmittal of torque), the engagement sleeve 120 is provided. The engagement sleeve 120 is axially disposed until the set of engagement members (e.g. castellations) 124 on the engagement sleeve 120 engage the set of engagement members (e.g. castellations) 184 of the second element 180 and the set of engagement members (e.g. internal splines) 122 of the engagement sleeve 120 engage the set of engagement members (e.g. external splines) 162 of the first element 160. The term engaged shall refer to the interlock or meshing of two components (e.g., two sets of castellations engaging or two sets of splines engaging) so as to transmit rotational torque across the engagement. Each set of engagement members (122, 162 and 124, 184) are preferably disposed at a uniform spacing along the circumference of the body they are mounted to, formed on, or formed in.
In a preferred embodiment, the engagement sleeve 120 utilizes a differential engagement member 122, 124 configuration (e.g., the number of proximal and distal end engagement members 122, 124 are not equal). For example, in the embodiment shown, the differential configuration of the engagement sleeve 120 includes N number of engagement members (e.g. internal splines) 122 and N+1 (or N−1) engagement members (e.g. castellations) 124, and accordingly N engagement members (e.g. external splines) 162 on the first element 160 and N+1 (or N−1) engagement members (e.g. castellations) 184 on the second element 180. This differential engagement member 122, 124 arrangement can reduce the backlash therebetween.
For example, if an engagement sleeve 120 has sixteen diametral internal splines 122 and fifteen castellations 124, the differential configuration allows for minimal backlash at assembly. With the desired equal circumferential spacing, the sixteen splines 122 are spaced at 22.5 degree intervals and the fifteen castellations 124 are spaced at 24 degree intervals. With such a differential spline 122 and castellation 124 configuration, the rotational adjustment to align the voids and protrusions of the castellations (124, 184) and splines (122, 162) to allow engagement is (24−22.5)/2 or 0.75 degrees. A non-differential spline (i.e., having an equal number of splines and castellations) provides for more difficult arrangement. For example, if using a non-differential configuration (not shown) having sixteen splines 122 and sixteen castellations 124, the rotational adjustment to allow engagement of the castellations (124, 184) and splines (122, 162), respectively, is 22.5/2=11.25 degrees. Thus the above described differential configuration provides an adjustability roughly 15 times as fine as a non-differential (e.g., equal) configuration. A higher number of splines and castellations could be used, but this reduces the width of each spline and castellation which may not be sufficient for downhole or other high torque use.
The above mentioned adjustment translates into backlash required in the connector 100. For example, a 0.75 degree adjustment requires (π×4.123″×0.75°)/360° or 0.027″ of spline clearance to allow the castellations (124, 184) and splines (122, 162) to engage, respectively. This is 8% of the tooth width which is minimal.
After the engagement sleeve 120 is installed on the assembly of the first element 160 and the second element 180 (e.g., the set of castellations 124 on the engagement sleeve 120 engage the set of castellations 184 of the second element 180 and the set of internal splines 122 of the engagement sleeve 120 engage the set of external splines 162 of the first element 160) relative rotation therebetween is restricted. The engagement sleeve 120 can then be axially restricted from moving by any means known the art, which can include retaining the engagement sleeve 120 to at least one of the first element 160 or the second element 180. In the illustrated embodiment, axial movement of the engagement sleeve 120 is restricted by an optional retention sleeve 140 (see
The retention sleeve 140 includes an internal shoulder 152 to abut the proximal end 121 of the engagement sleeve 120, and thus the axial restriction of the retention sleeve 140 will retain the engagement sleeve 120 in an engaged position. In the illustrated embodiment, the retention sleeve 140 can be axially disposed circumferential the first element 160, the second element 180, and the engagement sleeve 120, and the threaded internal section 148 of the retention sleeve 140 threaded to the threaded external section 188 of the second element 180 to form the axial interlock. So assembled, the connector 100 can transmit axial loads, tensile loads, and torque across the connector 100. Although not shown, the retention sleeve 140 can be threadably connected to the first element 160, in addition to or in substitute of the threaded connection between the retention sleeve 140 and the second element 180, without departing from the spirit of the invention. Optionally, or in substitute to a threaded connection between the retention sleeve 140 and the second element 180, at least one set screw 149 can be engaged to the first element 160 to further inhibit threads 148 of the retention sleeve 140 from disengaging the threads 188 of the second element 180. The retention sleeve 140 is installed at a relatively low level of rotational torque as compared to the torque required to assemble conventional threaded connectors of a drill string (e.g., a box and pin), which can be advantageous when the use of high torque tongs is not possible, for example, when a connection is below a coiled tubing injector.
Optionally, at least one seal can be used. For example, a seal can be disposed in a groove 170 on the distal section 166 of the first element 160 to seal the first element 160 to the bore 186 of the second element 180. A seal can be used between any of the components of any embodiment without departing from the spirit of the invention.
During some operations, for example, pullout operations, there can be a high degree of axial misalignment between the first element 160 (and anything attached thereto) and the second element 180 (and anything attached thereto). After the retention sleeve 140 is unscrewed, as the distal section 166 of the first element 160 is retracted from the bore 186 of the second element 180, the engagement sleeve 120 is automatically disengaged.
The invention can provide a means to retain the engagement sleeve 120 to the first element 160, if so desired. Referring again to
To retain the distal movement of the engagement sleeve 120 in the area between the first element shoulder 172 and the first set of engagement members 162, an optional retainer ring 112 retains a split ring 110, as shown in
If so desired, the retention sleeve 140 can be installed prior to slidably retaining the engagement sleeve 120 to the first element 160. By utilizing a retention sleeve 140 that cannot be slidably disposed past the engagement sleeve as shown (e.g., shoulder 152), the slidable retention of the engagement sleeve 120 to the first element 160 further slidably retains the retention sleeve 140 to the first element 160, which has obvious safety and assembly benefits.
Retention sleeve 140 can also include an optional groove 151 for insertion of a seal. A seal retained in groove 151 can frictionally retain the retention sleeve 140 at any point along the outer surface of the first element 160, for example, to retain the retention sleeve 140 away from the distal end 103 of the first element 160 during makeup, typically when the first element 160 is the upper connection and the second element 180 is the lower connection. To disconnect the connector 100, the retention sleeve 140 is disconnected to allow axial movement and the first element 160 and the second element 180 can be axially separated. As configured in the illustrated embodiment, the retention sleeve 140 and the engagement sleeve 120 remain slidably disposed to the first element 160, even during disconnection, and thus have obvious safety, assembly, and disassembly advantages.
An alternate embodiment of the connection tool 200 of the present invention is shown in
The cross-sectional view of the connector 200 in
Before engagement, it can be desirable to preassemble several of the components. Turning now to
To use the preassembled components above to form a connector 200, the proximal end 201 of the first element 260 is connected to one part or component and the distal end 209 of the second element 280 is connected to a second part or component, with relative rotation between the two parts impossible or undesirable, but some degree of axial movement possible. Before the first element 260 is stabbed into the second element 280, the first engaement sleeve 240 is preferably disposed on the second element 280 so that the distal fingers of the collet 250 are retained in the profile 288 of the second element 280, but the proximal fingers of the collet 250 are not restricted from any outward radial movement to allow the proximal fingers to engage the profile 268 in the first element 260, as shown in
The narrow distal section 266 of the first element 260 can then be stabbed into the bore 285 of the second element 280 until reaching a desired insertion, preferably when the proximal fingers of the collet 250 are adjacent the profile 268 in the first element 260. The first engagement sleeve 240 can then be axially disposed towards the proximal end 201 of the second element 280 until the inner bore of the first engagement sleeve 240 is circumferential the collet 250, and thus retaining both the proximal and distal fingers of the collet 250 in the respective profiles (268, 288) of the first element 260 and the second element 280. So assembled, the first element 260 and the second element 280 are axially connected to each other but not rotationally connected. The first engagement sleeve 240 is axially disposed and/or rotated until the proximal set of engagement members 244A are engaged with the set of engagement members 264 formed in the first element 260. The second engagement sleeve 220 can then similarly be axially disposed towards the proximal end 201 of the first element 260. The engagement sleeve 220 is engaged to the second element 280 and the first engagement sleeve 240 by axially disposing and/or rotating the engagement sleeve 220 until the engagement members 224 of the engagement sleeve 220 engage the distal set of engagement members 244B of the first engagement sleeve 240 and the engagement members 222 (see
As previously discussed in reference to the embodiment of
Numerous embodiments and alternatives thereof have been disclosed. While the above disclosure includes the best mode belief in carrying out the invention as contemplated by the named inventors, not all possible alternatives have been disclosed. For that reason, the scope and limitation of the present invention is not to be restricted to the above disclosure, but is instead to be defined and construed by the appended claims.
This application claims the benefit of provisional application U.S. Ser. No. 60/718,812, filed Sep. 20, 2005, incorporated by reference herein.
Number | Date | Country | |
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60718812 | Sep 2005 | US |