US2175137A - Method and apparatus for intercepting oil well casing gases during a welding operation - Google Patents

Description

SUMMERS 2,175,137

E. G. IBTHOD AND APPARATUS FOR INTERCEPTING OIL WELL CASING GASES DURING A WELDING OPERATION Filed March 11, 1939 Oct. 3; 1939.

Patented Oct. 1 939 I v UNITED. STATES PATENT wOFFlCE" METHOD AND APPARATUS FOR INTEBGEPT ING OIL WELL CASING GASES DURING A WEIDING OPERATION Earl G. Summers, ClendeninQW. vs. v Application m 11, 19:9, Serial No. 201,312] a Claims. (01. 166-15) The present invention consists of a method and iswdished out, as indicated at 6. The head 5 and apparatus for intercepting casing gases for is provided with an annulus 'Iwhich circumoil and gas wells during a welding operation, an scribes the dished out portion 6 and has mountobject of which is to prevent the rising gases of ed on the free face thereof an elastic gasket 8.

5 the well from reaching the area where the joints The gasket 8 is provided with a central opening 6 of the inner casing pipes are being welded. through which the inner casing extends, the wall In modern well drilling it is preferred to unite, of the opening snugly embracing the outer peon the Job, adjacent ends of the inner casing riphery of the casing 4. The gasketis secured pipes by a welding operation but, because of the from displacement by a metal ring 9, the latter 10 fire hazard, this has heretofore been impractical. being superimposed on thegasket and provided 1 I have, after some experiment, found that the with an opening of a diameter co-extensive with present well drilling apparatus, with slight modithe diameter of the dished out portion 6 of the fication, may be employed to effectively" interbore of the head 5, at the upper terminal of the cept gases rising from the well, both inside and latter. The-ring 9 is clamped to the gasket 8 outside of said casing andtobypass said gasesto and flange 1 by nuts and bolts In. It will, of 16 a point remote fromthe well. course, be manifest that the gasket may be re- ,It is an important object of the invention to placed'at the option of the user. provide a method which is simple in operation The head 5 is provided with conduits or tubes yet effective to control the inflammable gases ll, extending laterally therefrom through which 20 rising from the well, the apparatus used for gasesintercepted by the gasket 8 are vented at a 20 carrying out this method being likewise charpoint remote from the wall.

acterized by simplicity, but positive in its opera- In order to prevent internal passage of gases tion to perform in accordance with the teachings throughthe casing 4, I provide a seal l2, which of the invention. in the present instance is shown to consist of an In carrying out my invention I have found that inflated tube or bag which engages the inner wall 25 Y a preferred form consists of a method and apof'the casing. Preferably the seal I! is of apparatus which will prevent the casing. gases from preclable length so as to provide an internal seal rising above a predetermined point, means emof-sufiicient magnitude to positively prevent any ployed for this purpose being positioned interpossibility of gas passing between the seal and 80 mediate the joint of the pipes being welded and the wall of the. casing. I prefer also that the so outlets in the casing through which the casing inner sea] II project below and above the outer gases are vented. seal or gasket during the welding operation of Other objects will be apparent from the 101- the first joint. Said inner seal remains. in the lowing description of the present preferred form first joint of the pipe. Of course, gases rising 88 of the invention, taken in connection with the in the pipe 4 are intercepted'by the seal l2 and accompanying drawing, wherein: compelled to return to the bottom of the casing 4 Fig. 1 is a side elevatlonal view of apparatus and pass upwardly betweenthe casings 4 and '3 employed for carryingout the present invention, for ultimate expulsion from the casing head into parts thereof being broken away to disclose dethe conduits II. It is, of course, to be under- 40 tails of the specific internal and external sealing stood that although an inflated tube [2 is shown 40 means employed, and and described, I may employ other kinds of seals Fig. 2 is a plan view taken on the line 22 of or plugs. Fig. 1, looking in the direction of the arrows. The first joint of the inner casing, which is to To illustrate the application of my invention, be welded, is indicated at l3, it being located just I have in the drawing, shown an outer oil well above the top of the inner seal It. This joint is 45 casing 3 and an inner casing 4 which may be at a point sufllciently above the gases to meof standard construction. The outer casing is ent possibility of the latter igniting during the equipped with a head or frame 5 which isdewelding operation. ppon oompletionof the weld, tachably engaged with the outer casing. The the sections of pipe going to make up the casing V internal diameter of the outer casing is in excess 4 are lowered into the well in a manifest manner. 50

of the external diameter of the casing 4 to perin conjunction with the seal l2. Consequently mit the inner casing to pass freely therethrough the seal 12 travels downwardly in the well with in a manner well known in the art. Likewise the the first two pipe sections. Said seal remains in inner diameter of the head 5 is of larger dia;m' this position until the first pipe section reaches eter than the external diameter of the casing 4 the bottom of the well and correspondingly until the last section of pipehas been welded to its sub-adjacent section.

With the apparatus of the present invention, it is manifest that the pipes can be lowered without breaking the seal notwithstanding the fact that the diameter of the joints l3 are in excess of the diameter 01' the casing 4. This is due to the fact that the gaskets 8, being made of elastic material; will yield, under pressure of the joints, the inner wall of the gasket'dipping downwardly into the dished out portion 8 of the head 5. As soon as a joint clears the gasket the latter will flex into engagement with the outer periphery of the casing immediately above the joint, in an apparent manner.

Various changes may be made in the details of description proportion and arrangement of parts within the scope of the claims hereto appended.

What is claimed is:

1. A method of intercepting gas in the casing of an oil or gas well while welding the proximate terminals of the inner casing pipes, which comprises internally sealing the inner casing of the well and sealing the space between the inner and outer casings, both seals being below the zone oi the welding operation.

2. A method of intercepting gas in the casing of an oil or gas well while welding the proximate terminalsof the inner casing pipes, which comprises internally sealing said casing and also sealing the space between the inner and outer well casings, the seals being initially positioned above gas by pass conduits in the outer casing and below the welding zone of the inner casing.

3. A method of interceptinggas in the casing of an oil or gas well during a welding operation on the casing pipes comprising the employment of means to prevent gases irom rising in the well above a predetermined point, which point is below the'welding zone ofthe pipes.

4. Means to seal oil and gas well casings against the rise of gas while welding the inner casing'jypipes, including, in combination with a pair of concentric casings, sealing means removably mounted within the inner casing, and sealing means on the outer casing and spanning the space therebetween and the inner casing, said sealing means being located at a point below the zone of welding operation.

5. Same as claim 4 in addition to which the second said sealing means is yieldable to flex under pressure of'the welded joints of the inner pipe passing therethrough.

6. In combination with concentric oiland gas well casings the inner of which consists of a series of jointed pipes, means to seal the casings against the rise of gas above a predetermined point in the casings, during a welding operation on the casings, comprising a seal within the inner casing, and a seal carried by the outer casing and extending into engagement with the inner casing at the zone of the inner seal, the seal of the outer casing being flexible to yield under pressure of the pipe joints passing therethrough.

7. A step in the method of intercepting gas in the casing of an oil or gas well while welding the proximate terminals of the pipe sections going to make up the inner casing of the well which comprises internally sealing the first section at a point appreciably below its upper terminal and also sealing the space between the inner and outer well casings, the outer seal circumscribing the inner seal.

8. A method of sealing the casings of oil and gas wells, while welding the proximate terininals of the inner casing pipes, against the rise or gas from the well comprising internally sealing the first section of the inner casing preparatory to lowering said section into the outer well casing, the seal being located at a point remote from the upper terminal of the section, the space between the inner and outer casings being also sealed, said latter seal being flexible to yield under pressure of the enlarged joints of the inner casing sections while the latter are being lowered into the well through the outer casing.

EARL G. SUMMERS.

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