US1744380A - Casing spider and the like - Google Patents

Description

Jan. 21, 1930. R. H. FOLSOM 4,

CASING SPIDER AND THE LIKE Filed March 25, 1928 2 Sheets-Sheet 1 I N VEN TOR.

Jan. 21, 1930.- R. H. FOLSOM' 44, 8

CASING SPIDER AND THE LIKE Filed March 25, 1928 2 Sheets-Sheet 2 INVENTOR.

Patented Jan. 21, 1930 ROBERT E. FOLSOM, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO JOHN GRANT, 013

LOS ANGELES, CALIFORNIA CASING SPIDER AND THE LIKE App1ication filed March 23, 1928.

The present invention relates to casing spiders and analogous devices such as are employed for holding oil well casing drill pipe, tubing and the like in vertically sus pended position.

Devices of the class mentioned usually comprise a ring or annular body providing a central cavity of decreasing diameter downwardly, in which cavity suitable wedges or slips are arranged so that the weight of the slips and the weight of pipe held thereby, causes the slips to descend in the cavity until they are securely wedged between the ring and pipe. In oil well practice the weight of the casing may be as much as tons, which,

acting on the ring thru the wedges imparts what would ordinarily be a great bursting strain on the ring. Such strain however is largely reduced or resolved into a vertical stress by reason of the fact that the angle of the wedging surfaces of the ring is within the angle of friction, or about 15 degrees included.

. Such angle gives rise to jamming on the part of the wedges to the extent that they do not release when the weight is relieved. Such jamming is highly objectionable, not to mention the required operation of lifting the casing to release the slips, particularly when the casing is being lowered into the well.

The main object of this invention is to provide a device of the class described in which the slips will release automatically when all-owed to do so and without necessity for lifting the casing. Actually, the invention contemplates the employment of the weight of the casing for releasing the slips, whereas in the usual device the weight is the cause of the major difiiculties.

Other objects and advantages of my invention will appear hereinafter.

In carrying out my invention I may employ the usual ring and slips assembled within the ring. However, between the ring and the slips I provide means whereby downward motion or tendency on the part of the slips results in an upward movement or tendency on the part of the ring. I provide means for holding the ring down when desired and by Serial No. 264,070.

releasing the last named means the weight of the pipe or casing is free to act on the slips to move them down and to co-ordinately force the ring upwardly. The means disposed between theslips and ring is radially expansible on upward movement of the ring to release the slips. The ring may be held in uppermost position while the slips are being removed or installed, and when allowed to gravitate back to normal position, the ring acts to move all parts of the device into normal position.

I have illustrated one practical embodiment of my invention by the accompanying drawings in which:

Figure 1 is a view in vertical mid section of such embodiment.

Figure 2 is a full plan view thereof.

Figure 3 is a view in side elevation thereof.

Figures 4 and 5 are similar to Fig. 1 and show the device in various positions as will be explained hereinafter.

' In the embodiment illustrated the slips 6 re of the usual form; being provided with external tapered surfaces 7 and equipt with cyebolts 8 or the like for the receipt of the usual handles (not shown) whereby the slips are lifted into and out of place. The device provides the tapered bore 9 of decreasing diameter downwardly for receipt of the slips 6. The bore 9, however is provided by an annular assembly of liner sections 10, 10, 10, 10, which jointly provide that which may be termed a radially expansible liner. The outer surfaces 11 of the liner are inclined to converge upwardly and the liner as a unit may he said to possess an internal bore of decreasing diameter downwardly, and an ex ternal circumferential surface of decreasing diameter upwardly.

The liner is encompassed by the ring 12 adapted for vertical movement and coacting with the liner section so that downward movement of the ring crowds the liner sections together in compact slip-holding formation (see Fig. 1) while upward movement of the ring expands the liner to the slip releasing position in which the liner is shown in Figs. 4 and 5. Dovetail feather keys 14 hold the liner sections in connection with the ring 12.

A base plate 15 is provided on which the liner sections rest at all times and upon which said sections are shiftable radially even under superimposed weight. Accordingly the under surfaces 16 of the liner sections and the, upper surface 17 of the base plate are suitably machined and lubricated if required. The base plate provides a large central aperture 18 around which the liner sections are disposed. Said aperture is large enough to ass a pipe collar 19 or other annular enargement on pipe or casing 20.

The base plate is provided with circumferentially spaced horizontally directed yokes 21 each opening horizontally as at 22 in the same direction: considered circumferentially of the base plate. The plate is also provided with underlying arms 21. The ring is provided with corresponding radial pins 23 arranged to enter the open end of the corre sponding yoke by reason of the ring being turned on the base plate in the direction in dicated by the arrow in Fig. 2. The yokes are spaced so as to keep the ring concentric with the base plate and the aperture 18 at all times. Each yoke is provided with an upper detent surface 24 so that the pins may repose in the detents as shown in Fig. 5, to hold the ring in lifted position and to hold the liner in fully expanded slip-releasing position.

The included angle of surfaces 7 and 9 may be within the angle of friction while the angle of surface 11 should be in excess of the angle of friction so that spreading action of the liner will impart an upward tendency to the ring.

In considering the action of the device, reference is first had to Fig. 1, which shows the device in normal pipe-holding position. In this position the slips are held against descent solely by reason of the fact that they cannot descend further without spreading the liner, and the liner cannot spread because the ring is held down by reason of the pins being lodged each in under the corresponding yoke. To release the slips the procedure is as follows: The casin which is being lowered, is supposedly held y an elevator and lines (not shown) in such manner that the casing may descend an inch or two before taking up all slack in the lines. The ring, by means of bars 30, or by means of turning the casing directly, is turned until the radial pins are moved from under the yokes. The casing and the slips begin to descend toward the position in which they are shown in Fig. 4. This descent of the slips spreads the liner and lifts the ring. The casing has now been brought to rest by the elevator and lines. The slips may be lifted from the liner with the parts as shown in Fig. 4 but it is best to again turn the ring slightly until the pins rest in the upper detent surfaces 24 of the yokes, as shown in Fig. 5. In the position shown in Fig. the weight of the ring is held by the pins and yokes and the liner remains expanded fully as shown. Since the ring is not crowding the liner, the slips may be readily removed leaving only the base plate, liner and ring respectively in assembly, as shown in Fig. 5. Now the device will pass any enlargement such the pipe collar, either during raising or lowering of the casing.

When it is desired to again set the slips to hold the casing solely by the device, the ring is turned slightly until the radial pins are disposed in under the yokes as shown in Fig. 1. To do this the device, when in the position shown in Fig. 5 is manipulated so that the ring turns clock-wise a few degrees. This allows the ring to drop and crowd the liners together. The ring is then turned anti-clockwise to move the pins under the yokes. The ring and liner sections are then ready to serve in the same capacity any casing spider or like device and all parts may then become disposed in the normal operative position in which they are shown in Fig. 1.

It will be apparent now that I have provided an annular slip receiving body providing the requisite bore of acute angularity while capable of either automatic or manual operation to release the slips by changing the elfective diameter of the said bore, all without subjecting the device to excessive bursting strains, and in which device all radial stresses may be wholly or partially resolved into vertical stresses so that the weight of suspended pipe actually acts to release the slips from the wedged position in which they are shown in Fig. 1, while the weight of the ring when in the position shown in Fig. 5 is depended upon to move the liner back to normal contracted position.

While I have shown and described a speciiic embodiment of my invention I do not limit myself to any specific construction or arrangement of parts and may employ any construction or ar 'angement of parts without enlarging the scope of my invention, within the appended claims.

I claim:

1. In a device of the class described, a ring having vertical movement, slip wedges having vertical movement within said ring, and means coacting with said ring and wedges whereby downward movement of said wedges imparts upward movement to said ring.

2. In a device of the class described, a ring having vertical movement, slip wedges having vertical movement within said ring, and means coacting with said ring and wedges whereby downward movement of said wedges imparts upward movement to said ring, and releasable means for holding said ring down.

In a device of the class describes, an annular expa-nsible liner providing a bore of decreasing diameter downwardly, slip .1 wedges arranged in said bore to expand said liner by downward movement with regard thereto, and a ring encompassing said liner so as to be forced upwardly by expansion of said liner.

4. In a device of the class described, an annular expansible liner providing a bore of decreasing diameter downwardly, slip wedges arranged in said bore to expand said liner by downward movement with regard thereto, and a ring encompassing said liner so as to be forced upwardly by expansion of said liner, and releasable means for bolding said ring down.

5. In a device of the class described, pipe engaging means movable downwardly to engage and upwardly to release a pipe, holding means associated with said pipe engaging means so as to be urged upwardly bf downwardmovement of said pipe engaging means, and other means operatively connecting said pipe engaging means and said holding means whereby movement is transferred from the first means to the second means.

6. The device as in claim 5 and in which said holding means is mounted to gravitate from upper position to normal position.

7. In a device of the class described, an annular expansible liner, a horizontal base plate supporting said liner, slip wedges within said liner acting on downward movement to expand said liner, means urged upwardly relative to said base plate by expansion of said liner; said means being releasably locked to said base plate.

8. The device as in claim 7 and in which said last named means is mounted to gravitate from upper position to normal position to move said liner from expanded position to normal position.

9. In a device of the class described, a base plate provided with an aperture, an expansible annular liner resting on said plate concentric to said aperture and providing an internal bore of decreasing diameter downwardly and an external surface of decreasing diameter upwardly, slip wedges having vertical movement in said bore, and a floating ring embracing the said external surface of said liner.

10. The device as in claim 9 and further including releasable locking means for looking said ring to said plate.

11. The device as in claim 9 and in which said ring is adapted for both vertical and rotary motions; said device including releasable means for locking said ring down to said plate operable by rotary motion of said ring.

12. In a device of the class described, a base plate provided with an aperture, an expansible annular liner resting on said plate concentric to said aperture and providing a bore of decreasing diameter downwardly and an external circumferential surface of decreasing diameter upwardly, slip wedges having vertical movement in said bore, a floating ring embracing the external surface of said liner, and releasable means for locking said ring to said plate against vertical movement; said means comprising radial pins projecting from said ring and horizontally directed yokes to said base plate under which yokes said pins are movable.

13. In a device of the class described, a base plate, a sectional liner having sections annularly arranged on said base plate for radial movement, said liner providing a bore of decreasing diameter downwardly and further providing an external surface of de creasing diameter upwardly, a ring fitted over said liner whereby radial expansion of said liner Causes upward movement of said ring and whereby downward movement of said ring moves said liners from expanded position to normal position, slip wedges in said bore and releasable means operable by rotary movement of said ring about the vertical axis of said liner.

ROBERT I-I. FOLSOM.

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