US1193769A - Egbert w - Google Patents

Description

ROBERT W. CUSHING, F LEETONIA, OHIO.

CASNG-PLUG.

Specification of Letters Patent.

Patented Aug. s, 191e.

Application led December 16, 1915. Serial No. 67,171.

vTo all whom it maylconcwt:

. vantage the bottom of the casing is very liable to bev Be it known that I, ROBERT W. CUsHING, a resident of Leetonia, in the county ofl Columbiana and State of Ohio, have-invented a new and useful Improvement in Casing- Plugs, of which the following is a specification. u

- This invention relates to a casing plug for use in oil and other drilled wells.

In drilling deepoil or gas wells water is almost invariablyT :struck at different levels. When water is encountered it is usual practice to case the well'throughout each water bearing stratum and to lower therethrough a string ofcasing of a lesser diameter through which drilling isl continued. It is of great adinto wells that the lower end of the casing be plugged, so that Iwhen water is reached, the resistance of the water will tend to support the string of casing and take a large proportion of the strain due to the weight of the casing from the upper portion of the casing, the lowering tackle and`the derrick. It is also of great advantage to exclude water from the interior of the casing, as this does away with the necessity of pumping water from the interior of the casing before drilling may be resumed. Heretofore when plugs were used for this purpose, namely, to close -the lowermost portion of a string of well casing, able; plugs which could be broken by dropping weights upon them having been used. Where the water is 2 500 feet deep or.

over a heavy plug or disk 1s required, and

damaged when breaking this plug ory disk.

The object of the present invention is to provide a casing plug which may be securely applied to the lowest section of a str' g of casing and completely plug the same, and which may be readily attached to the casing and also readily removed therefrom Without injury to the plug or casing.

A further o ject of the invention is to provide a casin plug in ycombination with means where y it may be brought into p0- sition'in-jfa' casing or removed completely therefrom byoperations performed at the mouth of the well. v

' A still further object or the invention is to provide a casing plug with'the advantages above described, which is simple in constrllf in lowering such a string of casing `rality o the plugs have not been remov- 1 and inwardly and 'toothed portion on the interior periphery of i 10 is inclined 'downwardly and outwardly. This gives an engagement tion, cheap toU manufacture, and whichn possesses great strength and durability.

In the accompanylng drawings Figure 1 is a vertical sectional view of the casing plug showing the same in position in the casing 'with the expanding mandrel therein; Fig. 2

ation of breaking the engagement between the plug and casing and showing the engagement of the spear and plug;Fig.'3 is a cross sectional view on the line 3 3 Fig. 2i; Fig. 4 is a cross sectional view on the line 4-4 Fig. 2; and Fig. 5 is a view illustrating a modified form of engagement between the plug and casing. p

The. body l of the plug is tubular in form and is of a size to fit loosely within the casing 2 which is generally of a standard diameter. The body 1 'is split vertically for the reater part of its length into a pluarms 3, leaving a lower cylindrical portion 4c which is screw threaded internally as at flto provide a secure engagement with a plug or stopper-member 6. This plug member is provided'with a packing disk or ring 6a of rubber, leather, or someJ suitable composition, cient diameter to engage closely to prevent the passage of through the casing. The body member of the plug is formed of a suitable resilient metal so that the arms 3 possess consider.- able elasticity and may be readily forced into or out of contact with the interlor of the casing.o Each of the arms is modified at its the casing wall fluid l which is of suiiiupper extremity to form a locking member 7 provided with a plurality of teeth 8 arranged to engage similar' teethf9 formed on the interior of the casing sectlon,

or preferably on Vthe interior of a special tubular section 10 secured inthe caslng 2 between adjacent sections thereof. The en- 4; .of the drawings the toothed surface on the parts7 is inclined upwardly.

the circumferentially the member casing.

between the toothed portions of the plug body and the casing which assists in preventing upward displacement of the plug in the casing due to pressure upon the lower .extremity ofthe plug.

As illustrated in Fig. 5 of the drawings, the contacting toothed surfaces 8 and 9 of the arms and member 10 respectively are verticalfbut each of the arms is provided with a projection 12 which engages with continuous shoulder 13, 13a, on the inner periphery of the member 10. This engagement secures the plug from either upward or downward displacement in 'the casing without decreasing the interior diameter of the casing at this point, and thereby interfering with the insertion Aof a drilling tool when the plug is removed.

When a string of casing isto be lowered.

into a deepjwell in which water is present the casing plug is placed in position at the lower extremity of the casing. The'portions 7 of the resilient arms 3 are then forced outwardly by means of mandrel 14 so that the toothed surfaces 8 and 9 are brought into engagement. The mandrel 14 is provided with a shank 15 which' carries4 a screw threaded nub 16 to which may be attached a rod of any suitable char` acter for lowering the mandrel within the The mandrel is tapered so that it may readily enter between the members 7 of the arms 3 for expanding the same and may also be readily withdrawn therefrom. When the plug lis in position the packing disk or ring 6a on the plug or stopper member 6 will be forced upwardly by pressure from beneath so that it will act to tightly close the casing 2, and at the same time this pressure wlll cause toothed surfaces 8 and 9 of the members 7 and 10 to become more firmly locked against upward displacement.

It is important that .the plug may be readily removed .from the casing and drawn to the surface ofthe well when the casing reaches the bottom of the hole. For removing the plug from the casing the spear 17 is provided. This removing spear comprises a shank 18 having at its upper extremity a screw threaded nub similar to that upon the mandrel so that it may be connected to a long rod for insertion and removal by means operable from the mouth of the well. The lower portion 20 of the spear shank is of decreased diameter and forms a circumferentialshoulder 21. a Secured to the portion 20 of the spear shank by means oftap bolts 22 is a cupped collar 23 which is spaced from shoulder 21 by spacing blocks 24 lheld in lace by tap bolts 25. The lower rim o the cup shaped collar 23 is brought to an edge, so that when it is forced downwardly against the edges 11 of .the resilient arm members body of the plug.

7 it will enter between the edges 11 of the arms and the interior casing wall to force the arms inwardly and break the engagement between them and the toothed portion of the member 10 At the lower extremity of the shank portion 20 of the spear there are secured a plurality of radially disposed' spring arms 26 arranged to be compressed ontheir passage .between the arm members 7 and to snap outwardly after passing these arm members and engage shoulders 27 thereon. These springs furnish a locking engagement whereby the plug may be withdrawn from the casing by withdrawal of the spear. The engagement between the arm members 7 and the portion 10 of the casing with which they contact, having been brokenl by the inser-v tion of the collar 23 as above described.

When the spear and plug have been'completely withdrawn from the well, the spear may be readily removed from within the' In order to remove the spear the stopper member 6 is rst unscrewed from the lower portion of the plug body, and a tube of the propersize is inserted from the bottom of the plug and l pushed upwardly -therein to compress the spring arms 26 so that they arc vdisengaged from the shoulders 27 on the arms 3. Spacing blocks 24 arethenremoved, tap bolts 22 are withdrawn, and collar 23 is slid upwardly on the spear shank so that its lower rim is withdrawn from the tips of the arms 3, upward movement of the collar on the spear shank being limited by the circumferential shoulder 21 The spear may then be withdrawn completely from'the plug and the tube removed. To

prepare the plug for another insertion into a well casing, it is necessary merely to replace the stopper member 6 The :particular purpose which the plug above described is designed to accomplish is that of plugging the lower-most extremity of a string of casing during its insertion into a water filled oil or gas well as has been above described. It is obvious however, that the plug may be used advantageously in lowering the casing to the bottom of an Artesian well, since in that case also it will greatly relieve the strain on the-upper portion of the casing and the lowering tackle during the' operation of inserting the casing.

It is obvious that the device above described is susceptible of a number of modioations without departing froml the spirit of the invention and no limitations other than those contained in the appended claims are to be imposed. 4

ll/Vhat I claim is l 1. A well 'casing plug comprising a tubular body having an expansible locking portion, means for expanding said portion,

and means on Asaid body for closing the means arranged to enter between said armsl well casing.

2. A well casing plugcomprising a tu@ bular body, resilient members on said body Aarranged to engage the well casing, means on said body arranged to close said casing,

andmeans for said casing.

3. A well casing plug comprising a longitudinally split body of resilient material, means for expanding a portion of said body to cause thel same to engage the casing wall,

causing said arms to engage and a member secured to said body and arranged to close said casing.

l. A well casing plug comprising a toothed casing portion, -a body member provided with toothed arms, means for bringing-said toothed varms into engagement with the toothed portion lof said casing, and means sev cured to said body member for closing said casing.

5. A removable closurefor well casings comprising a casing portion, a plug, interlocking connections between said plug and casing portion, means for maintaining saidmembers in mutual engagement, andmeans for breaking said engagement and removing said plug.

.6. A yremovable closure for well casings comprising a casing portion, a plug, interlocking connections between said plug and casing portion, means operable from the well mouth for establishing engagement between .said plug and casing, and means forbreaking said engagement between said plug and casing member and removing said plug.

7. A removable closure for well casings comprising a casing portion, a plug, interlocking connections between said plug andcasing portion, means Voperable from the well mouth for` maintaining the connection between said members, and means operable from the well mouth for breakingsaid engagement and removing said plug.

8. A removable closure for well casings comprising a casing portion, a plug, arms on saidy plug arranged to beexpanded to engage said casing portion, and removing and casing, to break the engagement therebetween and to engage said plug.

9. A removable closure for well casings comprising a casing portion, a plug, arms on sald plug arrangedto be expanded to engage sai casing portion, and a removing spear having a portion arranged to break the connection between said arms and casing anda resilient portion arranged to engage said plug.

10. A removable closure for well casings comprising a casing portion, a plug, arms on said plug arranged to be expanded to en-v gage said casing portion, `and a removing spear havino` a portion arranged to en ter betweenQ sai arms and-casmg for breaking engagement,

vupward displacement of said plug,

the connection therebetween and a resilient portion arranged to engage said plug for lcomprising an internally toothed casing portion andarranged at its lower extremity to close the casing, a plug body split vertically into aplurality of resilie nt arms, toothed portions on said arms arranged to engage the toothed portion of the casing wall, means for maintaining said toothed portions and said casing portion in mutual and means arranged to break said engagement and withdraw said plug from the casing.

12. A removable closure for wellcasings comprising a casing portion, a plug, interlocking connection between said plug and casing portion, means for establishing the connection between said members and a removing spear having a portionarrangedto break the c onnection between said plug and casing anda resilient portion arranged to engage said plug dfor removing the `same from the casing. v

13. A closure for well casings comprising a plug,resilient securing means on said plug,

and a mandrel operable from the welly mouth for Gexpanding said resilient means and securing the plug in a casing.

14. A removable closure for -well casings comprising a plug, resilient securing means on said plug, a mandrel operable from the well mouth for expanding said securing means, and means operable from the well mouth for breaking 4the connection between said securing means and the casing wall.

l5. A removable closurefor well casings comprising an internally toothed casing portion, a plug split vertically into a plurallty of resilient toothed arms arranged to engage the toothed portion of said casing, said toothed casing portion and toothed arms having an engagement tending t'o preven means for establishing engagement between said plug and casing.

16. A removable closure for well casings comprising a .casing outwardly of said casing, a plug, resilient members on said plug havlng toothed surfaces inclined upwardly and inwardly engage of the plug body and arranged to the toothed surface of thecasing portion, and means for establishingengagement between said plug and casing.

portion having an in' `ternally toothed surface 4inclined downwardly and 17 .'A-'removable closure for well casings comprising a casing portion having aninternally toothed downwardly and outwardly inclined surface, a plug split vertically lnto a plurality of resilient arms having surfaces inclined upwardly and inwardly of the plug body and arranged to engage the toothed .surface of the casing portion, and means for establishing engagement between said plug and casing.

18. A removable closure for well casings comprising a casing portion having an internal outwardly and downwardly inclined toothed surface, a plug split vertically into a plurality of resilient arms having upwardly and inwardly inclined toothed surfaces, and means operable from the well mouthy for maintaining the toothed portions of said arms in engagement with said toothed casing portion.

19. A removable closure for well casings comprising a plug, a casing portion having a toothed downwardly and outwardly inl clined internal surface, means on said plug arranged to engage the internal surface of sald casing portion, .means orlockmg sa1d engaging'means 1n posltlon, and means arranged to break the engagement between.

said plug and said casing.

20. vA removable closure for well casings comprising a'casing portion, a plug, interlocking connection between said plug and said casing portion, means for .establishing said connection and a removing spear having a portion arranged to break the connection betweensaid plug and Icasing and a plurality l of resilient members arranged to engage shoulders on said from the casing.

21. A removable closure for well casings comprising a casing portion, a plug split vertically into a plurality of resilient arms arranged to engage said casing` portion, means for maintaining said arms in engagement with said casingportion, and a removing spear having a portion arranged to enter between said casing portion and said arms for disengagingvthe latter and a plurality of resilient members arrangedto engage shoulders on said plug for removing the same from the casing.

22. A removable closure comprising a tubular member arranged to engage the interior of a casing and havlng a closed lower extremity for completely closing the casing, means situated interiorly of said plug for maintaining the plug 1n engagement with said casing, and means for removing said plug from said caslng.

In testimony whereof, I have hereunto set my hand.

noBrrvs/i` cUsHrNG.'

plug for removing same Witnesses:

HARRY E. READY, EDWARD DALZELL.

for well casings.

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