The present invention relates to maintaining the tension in a transmission line in a tubular, and in particular to an apparatus, an assembly and a method for clamping a transmission line in a tubular to maintain tension on the transmission line.
Wires, antenna and other electrical lines and devices may extend along tubulars in boreholes to gather and transmit information to devices inside the borehole and devices outside the borehole. Since the tubulars are subject to various physical forces including vibration, rotation, and linear motion, electrical lines extending through the tubulars are also subject to demanding physical phenomena. Loose antenna, wires and other electrical lines may be subject to additional stresses, resulting in physical damage to the electrical lines, disconnection or other potential problems.
An embodiment of an apparatus for locking a transmission line in a tubular includes a first clamp segment configured to surround at least a portion of the transmission line of the tubular, the transmission line having a longitudinal axis. The apparatus also includes a second clamp segment configured to surround at least a portion of the transmission line, the second clamp segment and the first clamp segment configured to apply radial forces in opposite radial directions when the first clamp segment is engaged with the second clamp segment, the opposite radial directions being perpendicular to the longitudinal axis, the radial forces operating together to maintain the transmission line in a fixed position relative to the tubular and maintain tension in the transmission line.
An embodiment of an assembly for maintaining tension in a transmission line includes a tubular, a transmission line extending through the tubular, the transmission line having a longitudinal axis, and a clamp device including a first clamp segment configured to surround at least a portion of the transmission line and a second clamp segment configured to surround at least a portion of the transmission line. The first clamp segment and the second clamp segment are configured to apply radial forces in opposite radial directions when the first clamp segment is engaged with the second clamp segment, the opposite radial directions being perpendicular to the longitudinal axis, the radial forces operating together to maintain the transmission line in a fixed position relative to the tubular and maintain tension in the transmission line.
An embodiment of a method for maintaining tension in a transmission line includes applying tension to a transmission line in a tubular to draw taut the transmission line into a tensioned state, and fixing the transmission line in the tensioned state by applying an axial force to a clamp device, the clamp device fixing the transmission line with respect to the tubular.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
Embodiments of the present invention relate to maintaining the tension of a transmission line in a tubular of a borehole.
Referring to
The tubular 102 may include any type of tubular, such as a drill pipe used for drilling a well or a completion pipe used for extracting fluids from the well. The tubular 102 may include a narrow-opening portion 106 at its end and a wide-opening portion 105 towards its center, defining a channel 103 through which fluids flow, such as drilling fluids or earth formation fluids. The line clamp assembly 100 may be made up of one single tubular 102 or of multiple tubulars or multiple tubular segments.
The transmission line 104 may be any type of wire, cable or conduit. As illustrated in
The tubular 102 also includes a transmission line channel 118 in the body of the tubular 102 through which the transmission line 104 extends. The transmission line channel 118 includes a shoulder 117 separating a wide portion of the channel from a narrow portion. The clamp device 111 includes a sleeve 110, which may also be referred to as a spacer 110. The clamp device 111 includes a first clamp segment 112, second clamp segment 113, third clamp segment 114 and a fixing mechanism 115, also referred to in the present specification as a nut 115.
As the nut 115 is screwed onto the wire channel 201 by the tightening device 116, which may be a screwdriver or other type of bit adapted to fit the nut 115, the nut 115 applies a force having an axial element to an end of the third clamp segment 114. The third clamp segment 114 exerts a force against the second clamp segment 113. Since the second and third clamp segments 113 and 114 contact each other along slanted surfaces, the third clamp segment 114 exerts a force having both an axial component and a radial component. In
The second clamp segment 113 exerts the axial component force against the first clamp segment 112. Since the second and first clamp segments 113 and 112 contact each other along slanted surfaces, the second clamp segment 113 exerts a force having both an axial component and a radial component. The radial component pushes the first clamp segment 112 in a radially-outward direction toward an inner surface of the transmission line channel 118, clamping the transmission line 104 with respect to the transmission line channel 118.
The axial component of the force exerted against the first clamp segment 112 is exerted against the sleeve 110, and is in turn exerted against the shoulder 117. Since the shoulder is stationary, a force equal to the force exerted against the shoulder is exerted against the sleeve 110. At least a portion of the force exerted against the sleeve 110 is transferred to the first clamp segment 112, the second clamp segment 113, the third clamp segment 114 and the nut 115. The radial component of the force exerted by the first clamp segment 112 against the second clamp segment 113 pushes the second clamp segment 113 inward to clamp the transmission line 104. The radial component of the force exerted by the second clamp segment 113 against the third clamp segment 114 pushes the third clamp segment 114 outward to press against an inside diameter of the channel to clamp the transmission line 104 with respect to the channel 118.
The threads 121 of the nut 115 engage the nut 115 with respect to the wire channel 201 to maintain a position of the nut 115 with respect to the wire channel 201. Accordingly, the clamping function of the clamp device 111 is maintained constant by the nut 115.
In one embodiment, the first, second and third clamp segments 112, 113 and 114 are cylindrically-shaped devices. In one embodiment, the cylinders include a slit that cuts through the cylinder in a radial direction and extends lengthwise along an axial length of the cylinders. In one embodiment, the first and third clamp segments 112 and 114 are cylinders having one flat end configured to face outward from the clamp device 111 and one tapered end configured to face inward toward a center of the clamp device 111. The tapered ends may be tapered to decrease in thickness from the outward facing end to an inward-most end or point. In contrast, the second clamp segment 113 may have tapered ends at each axial end of the second clamp segment 113, the tapered ends increasing in thickness from the ends of the cylinder toward the center of the cylinder (see, for example,
Referring to
Referring to
While
In addition,
In addition, in one embodiment, no nut 115 or other force-maintaining mechanism is used. For example, one or more of the clamp device, the wire channel 201 and the inside surface of the tubular 102 may have teeth, ridges or other engaging mechanisms, such that when a force is applied to the third clamp segment 114 to press against and engage the second clamp segment 113, the clamp device 111 is maintained in position, even when a force-applying apparatus is removed. While teeth or ridges are provided as an example of an engaging mechanism, embodiments of the invention encompass any engaging mechanism, such as an adhesive or solder.
The tubular 102 may include any type of tubular, such as a drill pipe used for drilling a well or a completion pipe used for extracting fluids from the well. The tubular 102 may include a narrow-opening portion 106 at its end and a wide-opening portion 105 towards its center, defining a channel 103 through which fluids flow, such as drilling fluids or earth formation fluids. The line clamp assembly 500 may be made up of one single tubular 102 or of multiple tubulars or multiple tubular segments.
The transmission line 104 may be any type of wire, cable or conduit. The transmission line 104 includes a wire channel 201, which may be a tube, such as a metal tube. The tubular 102 also includes a transmission line channel 118 in the body of the tubular 102 through which the transmission line 104 extends. The clamp device 511 includes a sleeve 510, which may also be referred to as a spacer 510. The clamp device 511 includes a first clamp segment 512 and a second clamp segment 513.
As illustrated in
In another embodiment, the inclination angle of the slanted surfaces of the first clamp segment 512 and the second clamp segment 513 are configured to prevent slippage between the first clamp segment 512 and the second clamp segment 513. For example, the inclination angle of the slanted surfaces of the first clamp segment 512 and the second clamp segment 513 may be less than an arctangent of the coefficients of friction (also referred to as the friction angle) of the first clamp segment 512 and the second clamp segment 513, respectively.
In addition one or both of the wire channel 201 and the inside surface of the tubular 102, as well as the clamp segment 512 or 513, may have smooth surfaces if the inclination angle of the slanted surfaces of the first clamp segment 512 and the second clamp segment 513 are below the friction angle. With the inclination angles being smaller than the friction angle, the mechanism will be self-locking even if the installation or setting force is removed. Accordingly, in such an embodiment, no shoulder 117 and no nut 115 are required.
In one embodiment, the spacer 510 is a partial cylinder, such as a half-cylinder or cylinder having a 180 degree to 200 degree arc. The spacer 510 is set on the wire channel 201 during fixing of the clamp device 511 and the spacer 510 is removed after locking the clamp device 511 into place. In such an embodiment, during normal operation, only the clamp device 511 is left in the tubular 102 to fix the transmission line 104 with respect to the tubular 102. Each of a force F generating device, the sleeve 510 and the inner-pipe clamp 107 is removed.
The locking mechanism 612 includes an inclined surface 615 configured to engage an inclined surface 614 of the clamp segment 613. When a force is exerted against the clamp segment 613 in an axial direction of the tubular 102 toward the locking mechanism 612, the clamp segment 613 is pressed radially outward toward the inner wall 617 of the tubular 102. In one embodiment, one or more of the inclined surface 615 of the locking mechanism 612, the inclined surface 614 of the clamp segment 613, the radially-outward-facing surface 616 of the clamp segment 613 and the radially-inward-facing surface 617 of the tubular 102 includes one or more of ridges, grooves, teeth or an adhesive to fix the clamp segment 613 into position between the locking mechanism 612 and the tubular 102.
In block 704, a force is applied to the temporary clamp to establish a predetermined tension in the transmission line. For example, one end of the transmission line may be fixed and the temporary clamp may be affixed to the opposite end. A user, machine, device or system may pull the temporary clamp to exert a predetermined level of force or stroke on the transmission line and to establish a predetermined tension level in the transmission line.
In block 706, a permanent clamp is applied to the transmission line. The permanent clamp may be located closer to an opening of the tubular than the temporary clamp. In one embodiment, the permanent clamp includes one or more clamp segments configured to surround at least a portion of the transmission line and to exert a force on the transmission line and on an inside diameter of a surrounding channel to fix the transmission line in place with respect to the surrounding channel. In one embodiment, the permanent clamp is fixed by mating a thread of a nut with a thread of an outer diameter of the transmission line. Alternatively, the thread of the nut may dig into an un-threaded portion of the transmission line. Alternatively, the permanent clamp may be affixed by any other clamping or fixing mechanism, such as by latches, teeth, etc. In another embodiment, no fixing mechanism is used, and the permanent clamp maintains its position relative to the transmission line and the surrounding channel by one or more of friction, an adhesive and solder.
In block 708, the temporary clamp tool is removed from the transmission line once the permanent clamp has been fixed to the transmission line and the channel surrounding the transmission line. Accordingly, the tension level of the transmission line is maintained by the permanent clamp.
According to embodiments of the invention, a clamping mechanism is provided that maintains a tension of a transmission line with respect to a tubular. The clamping mechanism may also prevent rotation of the transmission line. In addition, the clamping mechanism is adjustable after being inserted into the tubular to increase or decrease a clamp strength, and the clamping mechanism is insertable and removable from the tubular. Embodiments of the invention also include a temporary clamping mechanism configured to apply a predetermined level of tension to the transmission line while a permanent clamp mechanism is affixed to the transmission line. By fixing the tension of the transmission line and preventing rotation of the transmission line, the transmission line is able to withstand environmental stressed, including vibration and rotation of the tubular in a borehole.
While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
This application is a continuation of U.S. application Ser. No. 13/754,539 filed Jan. 30, 2013, the disclosure of which is incorporated by reference herein in its entirety
Number | Date | Country | |
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Parent | 13754539 | Jan 2013 | US |
Child | 15670570 | US |