US2606619A

US2606619A - Oil well safety device

Info

Publication number: US2606619A
Application number: US125914A
Authority: US
Inventors: Carl L Whigham
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-11-07
Filing date: 1949-11-07
Publication date: 1952-08-12
Anticipated expiration: 1969-08-12

Description

Aug- 12, l952 c. 1 .WH1GHAM OIL WELL SAFETY DEVICE.

Filed Nbv. 7, 1949 2 SHEETS-SHEET l I* #el l..

f l I.

Aug. 12, 1952 c. L.. WHIGHAM 2,606,619

OIL WELL 4SAFETY DEVICE 2 SHEETS-SHEET 2 Filed Nov. '7, V1949 lill; A

INVENTOR 2m l.. Wfl/HAM ATTORNEYS Patented Aug. 12, 1952 UNITED sTATss PATENT o-Frlcef Carl L. Whigham, Odessa, Tex.

Application November 7, 1949, Serial No. 125,914

8 Claims. V(Cl. 16S-14) 1. This invention relates to an oilwell safety device.

As is well known, it is necessary to service oil wells in various ways. For example, it is necessary from time to time to swab the well tubing, I

and this is done by connecting swabs to a rope socket connected to a line or cable which is reciprocated to raise and lower the swab repeatedly in the well tubing. The reciprocation of the swab is under the manual control of an operator, and it is the common practice to connect a nag to the cable, orotherwise mark a cable a given distance from the swab as a warning signal to show that the swab is nearing the top of the well. Very frequently, an operator will fail to see the flag, thus allowing the rope socket to be pulled up against the oil saver, causingy the line to break and allowing theswab to fall back to the bottom of the well. It is then necessary to perform the annoying and time-consuming job of fishing the swab from the well.

An important object of the present invention is to provide a novel safety device which automatically prevents a swab or other servicing tool from dropping into a well if the operator negligently permits the tool to be pulled upwardly too far with the resultant breaking of the line.

A further object is to provide such a device in combination with a well head whereby, in the event the line is broken, the well tubing can be closed olf and the device removed therefrom, carrying the tool and the broken line connected thereto, thus permitting the sealing oil" ci the engaged by the gripping means, whereby theV device may be disconnected from the well for the servicing of the tube, Vfor example, for the replacement of worn swab rubbers.

, 2 parts of the device and adjacent elements being shown in section,

Figure 2 is an enlarged transverse sectional view on line 2-2 of Figure 1,

Figure 3 is an enlarged vertical longitudinal sectional view .through the present device `showing portions of adjacent elements withl a well swab or similar tool shown in dotted lines, and

Figure 4 is a fragmentary View similar to Figure 3 showing theoperation of the means for limiting upward movement of arope socket associated with a well servicing tool.V

Referring to Figure .1, rthe numeral II] designates a conventional well head l'as-'a whole comprising the usual elementsforming a part of such structure and which need not be illustrated in detail. The well head includes the usualV master Other objects and advantages of the invention will become apparentduring the course of the following description.

In the drawing, I have shown one embodiment of the invention. `In this showing, f I 1 Figure 1. is a side elevation of aconventional well head and oil saver, the present inventionbeing shown in position relative fthereto and valve II operated by a `hand wheel I2. At the top of the well head is connected the usual eliminator I3. 1

The present device is indicated as a whole by the numeral I5 and is connected at its lower end in a manner to be describedto the eliminator I3, while the upper end of the device is connected as described below to a conventional oil saver I6. The device I5 comprises a sleeve I8 externally threaded at its lower end as at I9 for connection with the eliminator I3. At its` upper end, the sleeve I8 is internally threaded as at 29 for connection with the reduced lowerend 2l of a connector 22 forming` a part-of the present device as will become apparent below. The upper end of the-connector 22 is internally threaded as at 23 for threaded connection with the depending lower end 24 of the oil saver.

The sleeveA I8 has a tapered bore 29 diverging upwardly andv terminating atits lower lend approximately at the point 29. Below such point, the bore is cylindrical. A' y A pair of complementary slips 35i is arranged in the tapered bore 28. These slips are divided diametrically as shown in Figure 2 and theedges 3l of the slips are in proximity to `each other when the slips are at their lower limits of movement. At such limits of movement, the, lower extremities of the slips aresubstantially Vcoincident with the point 29. lrlhe slipsshave their outer faces tapered to correspond tothe taper of the bore 23, and they have their inner faces serrated -as at 32 to provide teeth adapted to grip the tool` or part thereof Yas further referred to below. Y I

Theswabbing of an oil well is-accornplished by connecting swabbing tools 35to-a line socket 3G connected yatits upper endto aflineor cable 3lr extending upwardly through a reduced opening 38 in the connector 22, thence upwardly through the oil saver for connection with the usual apparatus employed under the control of the operator for vertically reciprocating the swabs. The line socket 36 is provided with a reduced upper neck portion 40 into which the line 31 extends to be connected to the socket.

Near its lower end, the sleeve I8 is provided with diametrically opposite screws 42 threaded through the casing I8 and provided with jam nuts 43. These screws are normally inoperative and are turned inwardly under conditions referred to below to limit upward movement of the socket 36 to prevent engagement of the latter with the teeth of the slips 30.

Operation The swabbing operation is carried on in the usual conventional manner, the vertical reciprocation of the swab being under the control of the operator. If, through carelessness. or negligence, the operator fails to reverse 'the direction of reciprocation as the socketV 36 moves upwardly and before it strikes the bottom of the connector 22, such striking will frequently result in the breaking of the line or cable 31. With the present device, it will be noted that the internal diameter of the slips 3U is slightly less than the external diameter of the socket 36. As the socket moves upwardly under the conditions referred to, it will engage the teeth 32 of the slips and these elements will move upwardly over the tapered surface 28. 'I'his operation diametrically separates the slips to a suiiicient extent for the movement of the socket 36 therebetween.

If the line 31 then breaks, the spring 33, urging the slips downwardly, causes the teeth 32 to grip and hold the socket 36, thereby preventing its falling downwardly into the bottom of the' well. The present device thereby prevents the necessity for having to fish the tool from thewell.

Thereafter, assuming that the wellis flowing, the rubber'packing (not shown) conventionally used in the oil saver I6, is tightened around the cable 31 to prevent oil or gas leakage. The eliminator I3 is then tightened to they swab stem to prevent leakage therearound, whereupon the sleeve I8 is unscrewed from the eliminator I3 and raised together with the swab stem through the eliminator until the swab reaches the bottom of the latter. The master valve II is then closed, whereupon the eliminator, swab, swab stem, and the present device are lsafely removed from the well head, the well being kept under control by the closing of the valve II; The broken line and swab are removed, whereupon the Ydevice is replaced with a new swab therein to continue the operation'.

When the swab is being pulled out tovl replace worn swab rubbers, which is necessary several times during a day of swabb-ing, the screws 42 are turned inwardly approximately two turns, which places the ends'of the screws ,a distance apart closer than the diameter of the socket 36 below the neck 40, which will prevent the socket 36 from moving Vupwardly into engagement with the slips 36. The eliminator is then unscrewed from the well head, and lifted out, the eliminator, the present device and the VVoil saver beingrernoved intact. After the swab rubbers 'have been replaced, the swabl is set back in the well tubing andlet down untilthe eliminator reaches-the well'head. The eliminator is screwed into place and the bolts 42 are backed out the necessary distance to clear the socket 36, whereupon the device is ready for the continued swabbing of the well. The jam nuts 43 are employed at the inner and normal positions of the screws 42 to lock these screws against movement.

From the foregoing, it will be apparent that the present device greatly facilitates the servicing of wells by preventing automatically the dropping of a tool such as a swab into a well. It also will be apparent that the present device may be easily handled for removal and replacement, and that its use in combination with the conventional elements of an oil well permits the latter to be kept under `control at all times. The escape of oil and gas may be completely prevented, thus eliminating the usual fire hazard.

I claim:

l. A well safety device comprising a stationary vertical sleeve adapted to be xed above and in alignment with a well and having an upwardly diverging bore, a plurality of complementary slips having outer faces fitting said bore and inner serrated faces, a member fixed to the upper end of said sleeve and having a reduced axial opening therethrough for the passage of the cable of a servicing tool, said opening being smaller than the tool, a compression spring between said member and said slips urging the latter downwardly, and an oil saver above and connected to the upper end of said sleeve by said member.

2. In combination with a well and a servicing col suspended from a cable for vertical movement in the well, a sleeve at the upper end of the well in alignment therewith, said sleeve having an upwardly diverging tapered bore, a plurality of complementary slips in said bore and having tapered outer faces fitting said bore, said slips having inner surfaces adapted to grip the tool, when pulled upwardly to a predetermined extent to enter said slips, to prevent downward movement of the tool, a gas saver mounted above said sleeve and through which the cable extends, a connecting member between` the upper end of said sleeve and said gas saver for fixing the latter relative to said sleeve, said connecting member having an axial opening smaller than the tool and through which the cable extends, and a compression spring between saidconnecting member and the upper ends of said slips for urging the latter downwardly.

3. In combination with a well having a well head at the upper end thereof, an oil saver spaced above said well head, and a well servicing too-l having a cable connected thereto for moving the tool vertically in the Well, a sleeve fixed at its lower end to said well head and having an upwardly diverging tapered bore, a plurality of complementary slips in said bore having outer surfaces fitting said bore and inner gripping surfaces dening an opening slightly smaller than said tool whereby the latter, as it moves upwardly beyond a predetermined point, engages such slips to move them upwardly and enter thereinto to prevent downward movement of the tool into the well, and a connecting member carried by said sleeve at the upper end thereof and to which said oil saver is Xed thereabove, the cable extending upwardly through said connecting member and through the oil saver.

il. The combination set forth in claim 3 wherein said `connecting member is provided with an axial guide opening through which the cable extends, vand a compression springbetween said connecting member andthe upper end of said slips to urge thelatter downwardly. F

5. The combination set forth in claim 3 wherein said connecting member is provided with an axial guide opening through which the cable extends, and a compression spring between said connecting member and the upper end of said slips to urge the latter downwardly, the. tool having a reduced upper end and said sleeve being provided below said slips with radial screws movable inwardly to engage the tool below the reduced end thereof upon upward movement of the too1 to prevent the latter from entering said slips.

6. In combination with a well having a well head provided with a master valve, an eliminator fixed tothe top of said well head, an oil saver spaced above said eliminator, a well servicing tool, and a cable connected to said tool to reciprocate it in the well, a vertical sleeve in axial alignment with the well and xed at its lower end to said eliminator, said sleeve having `an upwardly divergng tapered bore, a plurality of complementary Slips in said bore having outer faces tapered to correspond to the taper of said bore and fitting therein, said slips having serrated inner surfaces defining an opening through the slips slightly smaller than the tool, whereby the latter, when it moves upwardly beyond a predetermined point, engages said slips to move them upwardly and enter thereinto to be gripped by said serrated surfaces to prevent downward movement of the tool, a connecting member carried by the upper end of said sleeve and to which the oil saver is xed thereabove, said connecting member having a reduced guide opening through which the cable extends to pass through the oil saver, and a compression spring between said connecting member and the upper ends of said slips to urge said slips downwardly, the tool, when engaged by said slips, being arranged wholly above said master valve whereby the latter may be closed to seal the well for the removal of said sleeve with the tool therein.

7. The combination set forth in claim 6 wherein the upper end of the tool is reduced, and radial screws carried by said sleeve beneath said slips and adapted to be turned inwardly to engage the tool below the reduced end thereof to prevent the entrance of the tool into said slips.

8. In combination with a well having a well head connected to the upper end thereof and including a master valve, and a well servicing tool having a cable from which the latter is suspended for vertical movement in the well, said tool having a reduced upper end, a sleeve in vertical alignment with the well and xed at its lower end to the well head, said sleeve having an upwardly diverging tapered bore, a plurality of complementary slips in said bore having outer surfaces fitting said bore, said slips having inner gripping surfaces defining an opening of slightly less diameter than the tool whereby the latter, as it moves upwardly above a predetermined point, will move said slips upwardly and enter th-ereinto to 4be gripped by said inner surfaces to prevent downward movement o-f the tool, a member fixed to the upper end of said sleeve and having an openingr therethrough for the passage of the cable, a compression sp-ring between said y member and the upper ends of said slips to urge the latter downwardly, the tool, when supported by said slips, being arranged wholly above said master valve whereby the latter may be closed to seal the well while said sleeve and the tool carried thereby is removed from said wellhead, and radial screws carried by said sleeve and movable inwardly to engage the tool below said reduced end to prevent the too-l from moving into said slips.

CARL L. WHIGHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,825,004 Livergood Sept. 29, 1931 2,109,546 McLagan Mar.1, 1938 2,241,333 Smith May 6, 1941 2,306,617 Dick Dec. 29, 1942 2,354,929 Rector et al Aug. 1, 1944 2,482,455 Bailey Sept. 20, 1949