US2251113A

US2251113A - Device for pulling pipes or well casings

Info

Publication number: US2251113A
Application number: US311504A
Authority: US
Inventors: Robert E Chapman
Original assignee: R E CHAPMAN Co
Current assignee: R E CHAPMAN Co
Priority date: 1939-12-29
Filing date: 1939-12-29
Publication date: 1941-07-29
Anticipated expiration: 1958-07-29

Description

July 29 1941- R. E. CHAPMAN 2,251,113

DEVICE FOR PULLING PIPS `OR WEL-L CASINGS Filed Deo. 29, 1959 @www MMX@ YQ@ @un j V H ai d ff/pizz. l??? 25d-effi' a 27m/*z @M mi Patented July Z9, 1941 A 'llllv'liCE FOR PULLING C'ASING giras entrai-r'.

`Robert 4ll. Chapman, Oakdale, Mass., assignorto, R. E. Chapman Company, Oakdale, YMass., -a 'corporation of Massachusetts f A Application December 29, 1939,'Seria'l No. 311,504Y

(ci. g55- 27) 4 Claims.

The present invention relates to an improved device for pulling pipes or well c'asings, such as are driven Vinto the ground in connection with the drilling of wells. When drilling an artesian well, it is customary to drive an outside pipe or casing into the ground as far as ledge rock, before placing the inner casing, and the later removal and salvage of this outside casing often presents great difculties.

The object of the present invention is to provide a pulling device, which will enable a pipe or casing to be readily withdrawn from the ground by utilizing a pulling force developed from the upstroke of the usual string of drilling tools. The device of the present invention is readily applied to a drilling rig, without removing any parts therefrom, and in operation, the impact of the drilling tools is applied to the casing being pulled, Without developing any shocks which will either injure the tools, or damage the casing. The above and other advantageous features of the invention will hereinafter more fully appear from the following description, with reference to the accompanying drawing, in which:

Fig. 1 shows a section of outside casing driven into the ground, with the upper portion of a string of well-drilling tools disposed within the casing. n

Fig. 2 illustrates the manner of assembling the parts of the pulling device on the casing and tools.

Fig. 3 illustrates the operation of the pulling device on the up stroke of the drilling tools.

Figs. 4 and 5 are detail views, in plan, of separate parts of the pulling device.

Referring to the drawing, a pipe or casing I is shown as having been driven into the ground as the drilling -of the well progresses. In the drilling of artesian wells, in accordance with the usual practice, this outside casing I, ranging from 8 to 14 inches in diameter, is driven in the required number of lengths, until ledge rock is reached, and when the drilling has been carried to the desired depth and the inner casing placed, it is customary to withdraw this outer casing for further use. Each length of casing I is threaded at its ends as indicated at 2, so that several lengths of casing can be joined together, as required, by couplings 3. Consequently, the upper end of the last length of casing that has been driven presents a coupling 3 extending above the ground level, where it is readily accessible for application of the pulling device of the present invention.

For the purpose vof withdrawing the Vcasing I, -a heavy cylindrical bushing 4 is provided having ane'xtern'al thread 5,-which` can be screwed into the open end of the top coupling 3. In order to expedite attachment :of the bushing 4, it is provided with opposed lugs 6 for receiving a suitable tool, whereby the bushing may be turned. The bushing 4 provides a central opening 1 of large enough diameter to freely permit passage of a string of well-drilling tools 8, including the heavy drill stem 8a, which are carried by a cable 9 connected to the usual cable socket IB.

When it is desired to pull the casing I, the tools 8, without the drill bit, are rst lowered through the bushing 4 and suspended in the position shown in Fig. 2. The bushing 4 is then held a sufficient distance above the coupling 3, to admit a second Ibushing or hammer II, having an outside diameter slightly less than the inside diameter of the casing I. The hammer II is in the form of a heavy ring providing a central opening I2 adapted to receive the neck lila of the socket IU. The hammer II also provides a radial slot I3, as shown in Fig. 4, to permit the passage of the cable 9 when positioning the hammer, which is then lowered until it engages a shoulder I4 formed on the socket I0, as indicated in dotted lines in Fig. 2. The bushing 4 is then screwed into the coupling 3, as shown in Fig. 3, and it is to be noted that a considerable portion of the inside of the bushing 4 overlies the outside portion of the hammer II.

When the drilling tools 8 are lowered and then raised by the usual drilling motion, the hammer II, being carried by the shoulder I4, will engage the bushing 4 on each up stroke, to impart a blow which is transmitted directly to the casing I through the coupling 3. The force of this blow is considerable, due to the weight of the tools 8, and is evenly distributed around the entire periphery of the casing I, so that an extremely effective force is applied upward, to pull the casing out of the ground. Since the outside of the hammer II makes a close fit with 4the casing I, it acts as a guide for the tools 8 on their up stroke, and so insures that the socket I0 will be centered in the opening I of the bushing 4 as a blow is delivered to the bushing 4, thereby preventing any damage to the tools and casing.

I claim:

1. A device for pulling pipe or well casing, comprising in combination, a casing within the ground, a string of drilling tools movable axially within said casing by a cable, a member secured to the upper end of the casing, having an opening through which the tools can pass, and a second member capable of being freely mounted on the upper end of the string of tools, without withdrawal of said tools from said casing and having an outside diameter greater than the opening in said first-named member, whereby said members come into contact on the upstroke of the tools to impart; a pull to said casing.

2. A device for pulling pipe or well casing, comprising in combination, a casing within the ground, drilling tools movable axially within said casing by a cable and its socket, a bushing secured to the end of the casing having an opening to permit passage of said socket and tools, a second bushing capable of being freely mounted on said socket, without withdrawal of said tools from said casing and having an outside diameter substantially equal to that of said casing, whereby opposed surfaces of said bushings are brought into contact on the upstroke of the tools to exert a pulling force on said casing.

3. A device for pulling pipe or well casing, comprising a casing within the ground, a string oi drilling tools 'connected .to a cable by a socket, a bushing threaded into a coupling carried by the upper end of said casing and having an opening to permit passage of said tools and socket, and a second bushing having a slot for receiving the cable to permit positioning of said second bushing on said socket, with upward movement of the tools by the cable serving to bring said bushings into contact to developy an upward pull on said casing.

4. A device for pulling pipe or well casing, comprising a casing within the ground, a string of drilling tools connected to a cable by a socket, a bushing threaded into a coupling carried by the upper end of said casing and having an opening to permit passage of said tools and socket, and a second bushing having a slot'I for receiving the cable, to permit lowering of said second bushing on to a shoulder provided by said socket, with upward movement of the socket by the cable serving to bring said bushings into contact to transmit a blow to said casing.

ROBERT E. CHAPMAN.