US2897898A - Well apparatus brake - Google Patents

Description

Aug. 4, 1959 Filed April 20, 1956 A WELL APPARATUS BRAKE J. S. WYNN 2 Sheets-Sheet l INVENTOR.

JOHN S. WYNN BY 5 o ATTORNEY Aug. 4, 1959 J w 2,897,898

WELL APPARATUS BRAKE Filed April 20, 1956 2 Sheets-Sheet 2 16 I] INVENTOR.

I JOHN s. WYNN L BY FIG. 6

AT TOR/V5 Y SW w IO 7 WELL APPARATUS BRAKE ,5 Application April 20, 1956, SerialNo. 579,606 8 Claims. ((31.166-212) This invention relates to well tools and more particularly it relates to an improved tool braking apparatus for preventing entangling of the tool with the running line due to the upward flow of fluid within a Well.

In the normal operation of a wire line tool in a flowing well or in a well using a gas lift recovery system, substantial surges of fluid flow often lift the tool upward entangling it with the suspending wire above the tool. This condition is hazardous, and sometimes causes damage to the tool as well as expensive fishing jobs. Inthe elimination of such occurrence, it is extremely important to provide a braking apparatus which is sensitive to small relative movements between the suspension wire and the tool and operates by locking quickly and positively, thus preventing the tool from being lifted by the fluid flow.

' The braking apparatus presently known in the art for preventing tools from being lifted by the fluid flow isnot fast acting or sensitive to small changes of conditions within the well. The operator using such braking devices-"must follow distinct procedural steps to release the brake once it is set. These steps waste valuable time and labor.-

It is therefore an object of this invention to provide an improved tool ascent braking apparatus which is durable, not complex in construction and operation, and is economical to manufacture. It is a further object of this invention to provide a fast acting self-setting and self-releasing well tool brake apparatus which is sensitive to fast changes of conditions within the member in which the tool is operating and requires a minimum amount of maintenance and attention from the operator. Additional objects will become apparent as the following description, which is-to be read in connection with the annexed drawings, proceeds. In these drawings:

'.Figure 1 is a. view partially in cross section showing the; braking apparatus with a well tool in operating position;

Figure 2 is a view partially in cross section showing a well tool with the brake apparatus in braking position;

Figure 3 is an isometric view partially in cross section showing an assembly of the elements of a preferred embodiment of this invention;

Figure 4 is an isometric view partially in cross section showing an alternate embodiment of this invention;

Figure 5 is a view of another alternate embodiment of the brake apparatus for operation within different size tubes; and 4 Figure 6 is a view partially in cross section showing still another embodiment of this invention.

Referring now to Figure 1, well tool or instrument 6 is shown within a tubular member 7, typically a well tubing containing well fluids. The tool is run, i.e., lowered and/or retrieved from the surface by a flexible suspension means 9, such as a wire line, wire rope, or the like, and may optionally include a jarring mechanism 10, or other intermediate weight members such as a sinker bar. A yoke 11 pivotally connects the jarring mechanism to 2,897,898 Patented Aug 4, 1959 2 the dog 13 at point 14. The wire line may also be directly connected to the dog as by clamps or welding. The dog 13 is connected through a pivot 15 to a tool cap 16 and lies within a recess 17 as shown in Figure 3. It' is important that the friction in the dog connections (pivot 15 and point 14) be at a minimum as achieved by a bearing connection which allows the dog to rotate freely under minute transverse forces applied to the connection points. The cap 16 may connect to the tool 6 by numerous means, as for example by threads 18 (Figure 3) 'or by a weld 20 (Figure 5). The dog13 has a frictional engagement face 22 which may be smooth or roughened. The shape of face 22 may be a point or a curved surface and in some cases might be a sector of an ellipsoid,'as shown in Figure 5 to allow it toengage varying diameter tubes. The face may be removable from the dog, as shown in Figure 6 and constructed of a material such as rubber which is different from that of the dog. It is important that the maximum distance from the center of rotation, pivot 15, to the face of the dog-the eflective length of the dog-be as great as the internal diameter of the tubular member in which the tool operates minus the distance from the center of rotation 'of pivot 15 to the outside wall of the tool. Otherwise, the dog in the braking position must extendlaterally a distance equal to or greater than the inside diameter of the tubular memberminus the effective outside diameter of the tool. This allows the dog in braking position to impart a wedging actionbetween the tool and the tubular member. Various modifications may be made to affect the dog sensitivity to tool ascent. For example, the apparatus might be eccentrically constructed, as shown in Figure 6; with the center of gravity of the rotative system 'as far out "of axial alignment with point 14 and. pivot 15 as possible. Another modification is shown in Figure 4 wherein springlfi rotates the :dog and thereby insures positive and immediate response of the dog when the ascent rate of pivot 15 exceeds that of point'14. The strength of the spring is'not particularly critical except that it must not deflect the dog to such an extent that the tool cannot be withdrawn from the tubular member. This embodimenthas the advantage that minor frictional resistance of the dog connections may be overcome and, in addition, causes the dog to act fast and eliminates any null points where the dog might otherwise be in equilibrium or balanced.

The dog is normally moved between its running or operating position as shown'in Figure 1 and its braking position as shown in Figure 2. When the ascent rate of the tool and pivot 15 exceeds that of point 14, the spring and/or the moment of inertia, of the rotative system above pivot 15, including the dog, in combination with the 'ars, wir'e line, etc., rotates the dog from non-braking or running to braking position. The rotational sensitivity of the dog is dependent upon the friction resistance of the point 14, pivot 15, and the location of the rotative systems center of gravity and, as indicated above, is desirably as high as possible.

In operation, the tool 6 is attached to the cap 16 which has connected thereto the brake assembly comprising dog 13, yoke 11, and jars 10. The Wire line 9 from the drawworks or the like is run through a conventional lubricator packing gland, not shown, and then connected to the jars. After the lubricator is connected to the top of the tubing 7, the tool, with its auxiliary braking equipment as shown in Figure 1, is lowered through the tubing. If, at any time, while the tool is being lowered or retrieved, or during static or holding operations, the upward fluid flow is sufficient to lift the tool, the dog automatically rotates and assumes a wedging or gripping position as indicated in Figure 2. When the upward fluid flow subsides to the extent the tool is no longer lifted, the weight of the tool will normally release the brake apparatus automatically. In the event the brake apparatus does not release by the tool weight, the operator takes tension in the wire line or utilizes the jars to release the dog from engagement with the tubular member. Thus if the brake is set within the tubing at any time when the tool is being run, held, and/or retrieved, it may be released an infinite number of times without being withdrawn from vthe tubing or running special fishing tools.

Manifestly, the construction as shown and described is capable of some additional modification and such modification as may be construed to fall within the scope and meaning of the appended claims is also considered to be within the spirit and intent of the invention.

I claim:

1. An apparatus including a tool for use within a tubular member, a dog, a pivot connection between said dog and said tool allowing said dog to assume a running position with said tool and a braking position extending laterally from said tool a distance equal to the internal diameter of said tubular member minus the outside diameter of said tool, a suspension means, a second pivot connection between said dog and said suspension means suspending said tool coaxially with said suspension means, whereby a tension stress between said pivot connection and said second pivot connection maintains said dog in said running position, and a compression stress between said pivot connection and said second pivot connection maintains said dog in said braking position.

2. An apparatus including a tool for use within a tubular member, a dog, a pivot between said dog and said tool allowing said dog to rotate from a running position in alignment with said tool to a braking position laterally extending from said tool, the effective length of said dog being sufficient to wedge said tool within said tubular member, a suspension means pivotally connected to said dog and suspending said tool coaxially along a common longitudinal axis with said suspension means, whereby when the ascent rate of said pivot exceeds the ascent rate of said suspension means said dog is rotated to assume a wedging position between said tool and said tubular member.

3. A braking apparatus for attachment to a tool and for use within a tubular member including a dog, a pivot connection between said dog and said tool allowing said dog to rotate between a running position in alignment with said tool and a braking position laterally extending from said tool to form a wedge between said tool and said tubular member and a flexible suspension means pivotally connected to said dog suspending said tool coaxially along a common longitudinal axis with said suspension means, said suspension means connected to said dog at a point above said pivot connection when said dog is in said running position, whereby when the ascent rate of said pivot connection exceeds the ascent rate of said suspension means said dog rotates about said pivot connection and wedges between said tool and said tubular member.

4. In an apparatus for suspending a tool along a common longitudinal axis with a suspension means within a tubular member the improvement comprising a dog pivotally connected to said suspension means, a second pivot connection between said tool and said dog allowing said dog to rotate from a running position in axial alignment with said tool to a braking position in'-which it wedges between said tool and said tubular member.

5. An apparatus including a tool for use within a tubular member, a dog, a pivot connection between said dog and said tool allowing said dog to assume a running position in alignment with said tool and a braking position extending laterally from said tool a distance sufiicient to form a wedge between said tool and said tubular member, a point face on said dog, a suspension means pivotally connected to said dog suspending said dog and said tool coaxially along a common longitudinal axis with said suspension means, whereby when said ascent rate of said pivot connection exceeds the ascent rate of said suspension means said dog is rotated from running to braking position preventing the tool from further ascent. 1

6. An apparatus including a tool for use within a tubular member, a cap removably connected to said tool, a dog, a pivot connection between said dog and said cap allowing said dog to rotate with respect to said cap and assume a running position in axial alignment with'said tool and a braking position extending laterally from said tool a distance sutficient to wedge between said tool and said tubular member, a suspension means pivotally connected to said dog suspending said dog and said tool coaxially with respect to said suspension means along .a common longitudinal axis, whereby when the ascent rate of said pivot connection exceeds the ascent rate of said suspension means said dog is rotated to wedge between said tool and said tubular member.

7. An apparatus according to claim 6 including means to impart a rotative force to said dog.

8. An apparatus according to claim 6 including a resilient member between said cap and said dog imparting a rotative force to said dog.

References Cited in the file of this patent UNITED STATES PATENTS Re. 7,902 Cross Oct. 2, 1877 1,092,508 Robinson Apr. 7, 1914 2,187,007 Barnes Jan. 16, 1940 2,287,319 Miller June 23, 1942 2,638,851 Soberg et al May 19, 1953 2,651,199 Collins et al Sept. 8, 1953 2,672,200 Patterson Mar. 16, 1954

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