US2251125A - Safety device - Google Patents

Description

y July 29, 1941. c. J. GARDNER SAFETY DEVICE Filed Jan. 2, 1940 u m. o 4 Q. n 5 ma m o@ 9 m m f L 4 Mmmm .m l@

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Patented July 29, 1941 SAFETY DEVICE charles J. Gardner, Bakersfield, Calif., assigner of one-half to Aram Peter Ohanneson, Shafter,

Calif.

Application January 2, 1940, Serial No. 312,002

(Cl. Z55-28) Claims.

This invention relates to a safety device for preventing the loss of instruments or other devices lowered through pipe in oil wells and the like.

In the drilling of oil wells, it is common practice to lower devices, such as a surveying instrument, sand line core barrel, or drill pipe dryer to the bottom of the well through the string of drill pipe. These devices are sometimes lowered in the well by a flexible line or cable, but are commonly inserted into the pipe at the surface of the well and permitted to drop to the bottom by gravity. In the event the bit becomes lost from the end of the drilling string, or breakage occurs in the string itself, the instrument or device will pass through the open end of the pipe and become lost in the bore. Fishing of the device from the well is made difficult due to its relatively small diameter and ability to become lodged in locations diicult of accessibility with a fishing tool.

It is an object of the present invention to prevent the loss of devices of the character referred to when lowered through a string of pipe in oil wells or the like.

Another object of the present invention is the provision of a safety device adapted to be lowered or dropped through a string of drill pipe or the like, and which will automatically become anchored in the pipe upon passage of parts of the device through an open end or fractured portion of the pipe.

A still further object of the invention resides in the provision of a safety device of the character referred to which is positive in its operation regardless of the relative position between the broken or fractured portion of the pipe and the adjacent walls of the well.

It is a further obj ect of the invention to provide a device of this character which will operate regardless of the circumferential position of the missing portion of the pipe.

This invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawing -accompanying and forming part of the present specification. This form Will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in .a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawing:

Figure 1 is a vertical sectional view partly in elevation showing the safety device in Ia string of drill pipe with its parts in one position of operation.

Figure 2 is a view similar to Figure 1 with the parts of the safety device in another position of operation.

Figure 3 is a transverse sectional view taken as indicated by line 3-3 of Figure 1; and,

Figure 4 is a transverse section-al view taken as indicated by the staggered line 4-4 in Figure 1.

In the drawing, one form of the safety device contemplated by the invention, is shown within a string of drill pipe I0, and is connected to a device I I such as a surveying instrument, sand line core barrel, or the like. Although the safety device is shown as being connected to the lower end of the device or instrument I I through a threaded pin and box connection, it should ,be understood that said safety device might be connected to the upper end of Said instrument, or might even be lowered into the drill string independently and in advance of the instrument, which could be subsequently lowered into the drill string.

The device includes upper and lower sections I 4 and I5 secured together through a coupling I6 threaded into the adjacent ends of said sections, the section I4 having a box portion II in its uppermost end threadedly receiving a pin I8 on the lowermost end of the instrument II. It is preferable to provide the sections and coupling of the same diameter so as to provide flush joints therebetween and obviate any possibility of the device becoming hung within the drill pipe Vas it gravtates therethrough.

Anchoring means in the form of slips 20 vare adjustably mounted on the member I4 for movement into and out of gripping engagement with the drill pipe I0. The means for mounting the slips may comprise downwardly and inwardly inclined dove-tailed guides 2I formed on the member I4 and sldeably engaging corresponding dovetailed portions 23 in the slips 20. When the slips are in their lowermost or retracted position on the guides 2l, as shown in Figure 1, their gripping teeth 25 do not extend beyond the outer face of the member I4, thereby obviating any danger of their retarding or preventing passage of the device through the drill pipe.

Suflicient upwardmovement of the slips 20 on the inclined dove-tailed guides 2l will expand said slips outwardly into gripping engagement With the Walls of the drill pipe, 4as shown clearest in Figure 2. The instrumentalities for eifecting such upward movement of the slips includes a stem 21 slideable through an opening 28 in the coupling I6 and having a head 29 slideable Within a bore in the member I4. The slips 20 are operatively connected to the head 29 through links 3I passing through radial slots 32 in the wall of the member I4. The upper ends of the links 3| are pivotally connected to the slips as at 33, and their lower ends extend into a slot 34 in the head 29 and are pivotally connected to the head as by a pin 35. A coiled spring 36 surrounds the stem 21 between the `coupling I6 and the headed portion 29 of the stem 21, and when under compression, tends to urge the stem and connected slips upwardly to cause an expansion of the slips into gripping engagement with the Walls of the drill pipe I0.

Means is provided in the lower tubular section I5 for normally holding the slips and stem in retracted position with the spring under compression during downward movement of the device throughl the drill pipe (Figure l). Such means includes a latch 49 pivotally mounted on a pin 4I secured in the walls of the tubular member- I5.l Said latch is provided with a nose portion 42 engageable in a recess or groove 43 at the lower end of the stem 21, there being a. coiled spring 44 actinglupon said latch to normally hold its nose portion in engagement with the recess and preventupwarcl movement of the stem. The tension of the latch spring 44 may be varied through an adjusting screw 45 threaded in the Wall of the member I5.

If upon passing through the drill pipe a break or open end is encoutered in the pipe, means is provided for automatically releasing the latch to permit movement of the slips into gripping relation with the pipe walls, thereby anchoring the device in the pipe and preventing its loss through the break or opening in the pipe. This latch releasing means includes a lever 49 pivotally mounted on a pin 50 secured in the walls of the tubular member I5 and carrying an element 5I extending through an opening 52 in the member I5. Said element is urged against the interior walls of the Ydrill pipe by a coil spring 53 acting on the lever 49. In the present instance, said element is in the form of a roller revolubly mounted in a bifurcated portion 49a. of the lever 49 by a. pin 54, so that a minimum of friction is encountered between the element and the pipe upon passage of the device through said pipe.

The lever 49 is provided with an extension 55 carrying an adjusting screw 55 which, upon operation of the lever, is adapted to engage an extension 51 on the latch 40 to release said latch and permit movement of the slips into gripping engagement with the pipe I9 under the iniiuence of the coiled spring 36 acting upon the rod 21. In the present form of the invention, spring elements 59 and $0 are provided on the exterior of the tubular member I5. These elements, cooperative with the element 5I under the influence of the spring 53, form resilient means engageable with the sides of the pipe I during lowering of the device therethrough, and maintain the device substantially centrally within the pipe as it moves therethrough. Furthermore, such arrangement insures proper operation of the lever 49 to trip the latch 40 upon passage of the lower end of the device beyond an open end of the pipe, regardless of the position of the pipe end with respect to the walls of the well bore. For instance, if, upon passing through an open end in the drill pipe I9, the element` 5I engages the wall of the bore due to the close proximity of the pipe end to said bore, the coiled spring 53 will move the lower end of the device away from the element or roller 5I, thereby tripping the latch 40. Such action is permitted by the passage of the spring elements 59-69 past the open end of the pipe. With the spring elements 59-69 and element 5I, operation of the lever 49 to release the latch is assured upon the passage of the element 5I or the spring elements 59 and 6I] through an opening in the pipe.

It should be understood that the springs 59 and 69 are not absolutely essential for utilization of the device, since instruments to which the device may be connected are commonly equipped with centralizing springs, which would tend to maintain the entire structure well centered within the drill pipe during its gravitation therethrough. It will be obvious how the element 5I, upon passing beyond an opening in the drill pipe, will be forced-outwardly beyond the pipe wall to eiect a tripping of the latch 40 by engagement of the screw 55 with the latch portion 51. As heretofore explained, such release will result in an upward movement of the stem 21 under the influence of the coiled spring 36 and an expansion of the slips into gripping engagement with the walls of the well, whereby to lock the apparatus against complete removal through an open end of the drill pipe.

I claim:

l. A safety device adapted for passage through a string of pipe in a well comprising, anchoring means engageable with the pipe, means normally holding said anchoring means out of engagement with the pipe, spring means engaging the sides of thelpipe operative upon passage past the point where said pipe is circumferentially incomplete for actuating said holding means to release said anchoring means for engagement with said pipe, said spring means comprising a plurality of means engaging said pipe at different circumferential points thereof, one of said spring means being operatively connected to1 the releasing means, whereby movement of any of said spring means beyond the normal wall of the pipe will release said anchoring means for engagement with said pipe.

2, A safety device adapted for passage through a string of pipe in a well comprising, a plurality of slips engageable with the pipe, means normally holding all of said slips out of engagement with the pipe, a lever engaging the wall of the pipe, meansurgng said lever into engagement with said pipe, and,` means connecting said lever with said holding kmeans and operative upon passage of said lever beyond the Anormal wall of said pipe to release all of said slips.

3. A safety device adapted for passage through a string of pipe in a well comprising, anchoring means engageable with the pipe, spring means for urging said anchoring means into engagement with the pipe, latch means normally holding said anchoringmeans out of engagement with said pipe, lever means engaging the wall of said pipe, spring means urging said lever means into engagement with the pipe, said spring means being operative to urge said lever means beyond the normal wall of said pipe upon passage of said lever means past a-point where the pipe is circumferentially incomplete, whereby to cause said lever to trip the latch and release said anchoring means for engagement with said pipe.

4. A safetydevice adapted for passage through a string of pipe in a well comprising, anchoring means engageable with the pipe, means normally holding said anchoring means out of engagement with the pipe, lever means, a roller on said lever means engageable with the walls of the pipe, spring means acting upon said lever means to urge said roller into engagement with said pipe, and means operatively connecting said lever means with said releasing means and operative upon passage of said roller past a point Where said pipe is circumferentially incomplete to operate said releasing means.

5. A safety device adapted for passage through a string of pipe in a Well comprising, a plurality of slips engageable with the pipe, a latch normally holding all of said slips out of engagement with the pipe, a lever having a portion engageable with the walls of the pipe, spring means acting upon said lever to urge said portion of said lever into engagement with said pipe, said lever having a second portion engaging said latch to release said latch upon passage of said rst mentioned portion of the lever oeyond the normal wall of the pipe, and means between said second mentioned portion of said lever and said latch permitting adjustment of the amount of movement beyond the normal Wall of the pipe of said rst mentioned portion of said lever which is necessary to engage said latch.

6. A safety device adapted for passage through a string of pipe in a well comprising a body member, a plurality of slips carried by said body member and engageable with the pipe, a single member mounted for relative movement on said body member, said body member and said movable member each having portions engaging the walls of the pipe, and means operated by outward movement of said movable member relative to said body member causing engagement of all of said slips with the pipe whereby to stop the device and anchor it Within the pipe.

7. A safety device adapted for passage through a string of pipe in a well comprising, a body member, a plurality of slips carried by said body member and engageable with the pipe, means normally holding said slips out of engagement with the pipe, a single member movably mounted on said body member, said body member and said movable member each having portions engaging the walls of the pipe, said movable member being operatively connected with said holding means to release said slips upon outward movement of said movable member relative to said pipe engaging portion of said body member.

8. A safety device adapted for passage through a string of pipe in a well comprising, a body member, a plurality of slips on said body member engageable with the pipe, means normally holding said slips out of engagement with the pipe, a single member mounted for relative movement on said body member, said body member and said movable member each having a portion engaging the Walls of the pipe, said movable member operative upon outward movement relative to said body member to release said slips for engagement with the walls of the pipe, said slips being operative to hold said device against downward movement but permitting movement in an upward direction.

9. A safety device adapted for passage through a string of pipe in a Well comprising, a body member, a plurality of slips on said body member engageable with the pipe, means holding said slips out of engagement with the pipe, a plurality of members engaging the walls of the pipe at different circumferential points thereof, and means responsive to the movement of one of said members with respect to the others to operate said holding means to release all of said slips for engagement with the pipe.

10. A safety device adapted for passage through a string of pipe in a well comprising, a body member, a plurality of slips engageable with the pipe, a latch normally holding all of said slips out of engagement with the pipe, a lever mounted for relative movement on said body member, said body member and said lever each having a portion engageable with the Walls of the pipe, spring means acting on said lever and said body member to urge said portions into engagement with the pipe, said lever having a second portion engaging said latch to release said latch upon relative outward movement of the first mentioned portion of the lever relative to the body member.

CHARLES J. GARDNER.

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