US1894912A - Process and apparatus for inserting tubing in wells - Google Patents

Description

Jan. 17, 1933. OTI 1,894,912

PROCESS AND APPARATUS FOR INSERTING TUBING IN WELLS Filed Sept. 26, 1929 2 Sheets-Sheet 1 H. C. OTIS Jan. 17, 1933.

PROCESS AND APPARATUS FOR INSERTING TUBING IN WELLS Filed Sept. 26, 1929 2 Sheets-Sheet 2 Patented Jan. 17, 1933 UNITED STATES HEBBERT C. OTIS, F SHREVEPORT, LOUISIANA PROCESS AND APPARATUS FOR INSERTING TUBING WELLS Application filed September 26, 1929. Serial No. 395,315. R E l S S This invention relates to a process and apparatus for inserting tubing, tools or other objects into gasor oil wells .against high pressure existing therein, whereby the loss of the gas or oil is prevented, and the insertion of the tubing more readily accomplished than has heretofore been possible.

The process and apparatus forming the subject matter of this application will be fully described hereinafter, reference being had to the accompanying drawings, of which:

Fig. 1 is a side elevation of an apparatus, designed to carry out the process;

' Fig. 2 is an enlarged sectional elevation of a portion of the apparatus;

Fig. 3 is a side elevation of an operating head adapted to be placed on the top of the well casing and the string of tubing after the1 latter has been inserted in the former;

Fig. '4 is a sectional elevation of the device shown in Fig. 3. 1

Referring to the drawings, 1 illustrates a Well casing which has been previously in serted into a well in the usual manner. 2 illustrates a string of tubing being lowered or forced down into the Well casing 1, against H the high pressure existing therein.

To prevent the escape of gas or oil from the upper end of the casing 1 around the tubing 2, a pair of control heads 3 and 4 of the type illustrated in my co-pending application Serial No. 319,865 filed November 16, l 1928, are provided on the upper endofthe casing 1.

The well casing 1 consists of a plurality of lengths of ordinary piping coupledtogether by the usual'form' of straight couplings, one of which is shown at 5 at the upper end of the well casing 1.

The control head 3 is secured to the coupling 5 by a nipple 6 having an annular with the tubing 2, as illustrated within the control head 4, or to be moved to an outer position, free of the tubing 2, as illustrated within the control head 3, so that the pipe connections 10 and appliances, such as the sealing device 13, may be passed through the control heads. At no time, however, are the jaws of both of the control heads out of contact with the tubing.

Secured to the fitting 9 of the Well casing 1 is a cross-arm 20 which, in the present instance, consists of a pair of similar beams located at opposite sides of the fitting 9 and clamped thereto by means of bolts 21, 21,

above the control head 4.

Rotatably mounted on the cross-arm 20 are sheave wheels 22,22, around which passes a cable 23. The opposite ends of the cable 23 are secured to the outer ends of snubbing levers 24, 24 respectively, which are pivotally mounted at 25 in a carrier 26 which is slidably mounted on the tubing 2, above the fitting 9, of the well casing 1. The cable 23 passes over a sheave located in a traveling block 27, or two cables may be used with their ends rigidly secured to the traveling block 27. The single cable, however, provides for equalization of the pressure applied to the snubbing levers 24, 24.

On the inner ends of the snubbing levers 24, 24 are pivotally mounted snubbing shoes 28, 28 which engage the tubing 2 and which are provided with teeth 29. The snubbing device is covered per se in my 00- ending application Serial No. 395,314, filed September 26, 1929.

Raising of the traveling block 19 will cause the teeth 29 of the snubber shoes 28 to end of a lever 34 which in turn is pivotally.

mounted on the cross-head 30. When the outer endof the lever 34 is pressed downwardly by means of a weight, spring, or manually operable lever bar, not shown, the shoes 32 and 33 will cooperate to hold the tubing 2 against vertical movement upward with respect to the casing while the traveling snubber shoes 28, 28 are being raised along the tubing 2 for the purpose of obtaining a new purchase on the said tubing.

The relatively fixed snubber 32 can be moved away from the tubing for the purpose of permitting the couplings 10, or other protuberances on the tubing 2 to pass, by back- I ing off the screw 35, after which the said fixed snubber is again set up into contact with the tubing 2.

In order to prevent the gas from escaping through the tubing 2 itself, during the inserting of the tubing into the casing, the temporary sealing apparatus 13 is provided. This device is covered per se in my co-pending applicaiton Serial No. 395,313, filed September 26, 1929.

The temporary sealing apparatus 13 comprises an outer sleeve 40 adapted to be thread- 'ed onto the tubing 2. The outer sleeve 40 is provided with an annular shoulder 41 on which rests a relatively brittle element, such as a cast iron disk 42, the disk being held tightly between the shoulder 41 and the end of one of the sections of tubing 2, which is screwed into the outer sleeve 40, and a packing element of any desired form being provided between the end of the tubing and the disk, or between the disk and the shoulder to prevent the escape of fluid under pressure around the disk.

The sealing apparatus 13 also comprises an inner sleeve 45 which is adapted to be threaded into one of the couplings 10 of the string of tubing 2 or which may form the upper end of the screen section 12 as illustrated in the drawings. Axial movement of the outer sleeve 40 into a seal breaking position relative to the inner sleeve 45 may be normally prevented by a shear pin, not shown, or by means hereinafter set forth.

In the present instance, the inner sleeve 45 is provided with suitable lugs, such as the heads of the screws 47, the said screws being threaded into the inner sleeve 45 with their heads disposed in vertically extending slots 48 formed in the outer sleeve 40.

In the upper end of the inner sleeve 45 is a pin or knife blade 50 which lies immediately, below the cast iron disk 42, and which is adapted to break the sealing disk 42 under conditions which will be hereinafter set forth.

The slots 48 are provided with shoulders 49 against which the lugs 47 are adapted to bear as shown in Fig. 2. The slots 48 are provided with inclined portions 46 which normally guide the lugs 47 under the shoulders 49, when the inner sleeve 45 is permitted to drop relative to the outer sleeve 40.

The string of tubing 2 is forced down into the well casing 1 against the pressure of the as or other fluid existing in the well casing, by the block 27 being raised and thereby exerting a pull on the cables 23, 23, which in turn exert a pressure on the snubbing shoes 28, 28, forcing them into gripping contact with the tubing and thereby forcing the tubing into the well, the holding snubbers 32 and 33 being operated to hold the tubing against being forced out of the casing while the snubbers 28, 28 are being moved upwardly along the tubing to obtain a new grip thereon, the control heads being operated to permit the couplings, etc., to pass through as the tubing is being lowered into the well casing.

After a certain amount of the tubing has been lowered into the well, through the casing, the weight of the tubing exceeds the pressure of the fluid existing in the well, after which the tubing will pass into the well of its own weight, being lowered by any suitable tackle and suitable drawbacks for controlling its passage into the well.

When the foot plug 11 reaches the bottom of the well, a measurement is taken from the top of the string of tubing, as it stands with the foot plug resting on the bottom of the well, to the shoulder 7 in the fitting 6, where-, upon the tubing is raised exposing above the top of the fitting 9 a greater amount of the tubing than the measurement taken. The measurement which has been taken is then laid out and a mark made on the tubing to show just how far from the top of the tubing the shoulder 7 is spaced, when the tubing is standing in the well with the foot plug 11 resting on the bottom of the well.

At a predetermined point below the above mentioned mark on the tubing the tubing is cut and threaded.

On this threaded end of the tubing is then placed a coupling 10a, see Fig. 4. A second disk 55 is then placed within the coupling, resting on the said threaded end of the tubing. A section of pipe 2a of predetermined length is then threaded into the coupling 10a and the end of the pipe 2a rests against the disk 55, holding it firmly against the above mentioned end of the tubing 2.

Around the pipe section 2a-is then placed a pair of steel rings 56 and 57 between which are located a series of packing rings 58, 58, after which another coupling 10b is threaded onto the free end of the tubing section 2a.

A section of tubing 26 of anydesired length is then threaded into the coupling 10b and a second pair of steel rings 60 and 61 with packing rings 62 therebetween is then placed on the section of tubing 21).

The string of tubing is then again lowered into the well casing until the foot plug 11 rests onv the bottom of the well. This foot plug 11 has a beveled edge 11a which presses into the bottom of the Well and acts to prevent rotation of the lower portion of the string of tubing, that is the portion up as far as the inner sleeve of the temporary seal 13.

After the foot plug 11 has been forced into gripping contact with the bottom of the well, the upper portion of the string of tubing, that is all above and including the outer sleeve 40 of the temporary sealing device 13', is turned until the shoulders 49 in this outer sleeve 40 ride off the lugs 47 carried by the inner sleeve 45, of the temporary sealing device 13, the lugs passing into the upper portions 48a of the slots 48 formed in the outer sleeve 40.

Axial movement of the said upper portion of the string of tubing is then permitted relative to the said lower portion thereof, and this relative axial movement causes the element 50 to engage the sealing disk 42. Downward pressure on the upper portion of the string of tubing causes the element 50 to break the disk 42, whereuponthe fluid under pressure entering the string of tubing through the perforated section 12 thereof flows upwardly through the tubing to the upper disk 55, where the flow of fluid is choked thereby.

This disk has a small opening 55a which permits a relatively small amount of the fluid under pressure to pass upwardly through the tubing section 25 giving a signal that the lower sealing disk 42 has been broken.

The axial movement of the upper portion of the string of tubing 2 which elfected the breaking of the disk 42 also provides sufficient movement to permit the rin 56 to seat on the shoulder 7 of the fitting 6, Whereafter the weight of the tubing causes the coupling 10?; to press on the ring 57 which expands the packing rings 58 into sealing contact with the inner wall of the fitting 6 above the shoulder 7 thereof.

This sealing bythe rings 58 prevents the leakage of fluid under pressure upwardly through the casing 1 around the tubing 2.

The control heads 3 and 4 and all the other apparatus located above the fitting 6 are then removed, for use in other places, leaving the tubing section 2?) projecting above the top of the fitting 6.

A pair of steel rings 60 and 61 with a series of packing rings 62 therebetween is then placed on the projecting tubing section 2?). A cap 65 having an internal flange 66 is then placed on the section of tubing 26. This cap is threaded at its end opposite the internal flange and these threads cooperate with threads on the upper end of the fitting 6, whereby the cap 65 may be screwed down on the fitting 6, the flange 66 engaging the steel ring 61 which in turn engages the packing rings 62. The packing rings 62 rest on the steel ring 60, which in turn rests on the upper end of the coupling 10?).

As the cap 65 is screwed down tightly onto the fitting 6 a fluid tight seal is formed between the casing 1 and the tubing 2 and the tubing 2 is held against any vertical movement which may occur and which would breakon the upper end of the nipple 7 3 is secured a second gate valve 75.

Into the upper end of the gate valve is threaded, or otherwise secured, a plug 76 having an internally threaded aperture adapted to receive a threaded rod 80.

This rod 80 projects downwardly through the plug 76, valve 75, nipple 73, T-fitting 72, nipple '71, valve 70, tubing section 25, coupling 10b, and tubing section 2a to a point adjacent the disk 55, the rod having apointed end adapted to enter the opening 550. in the disk 55 to close the same.

Into the third outlet of the T-fitting 72 a pipe line is connected having a valve 86 by which the flow of fluid from the tubing 2 into the pipe line 85 may be controlled.

The rod 80 is then turned until sufiicient pressure is brought to bear on the disk 55 to break the same whereupon the main flow of fluid is permitted through-the tubing 2 into the pipe line 85.

The rod 80 is then turned so that it is backed out of the plug 7 6, the valve 75 being closed as soon as the pointed end of the rod 80 passes the gate of this valve, thereby preventing escape of fluid through the plug 76 after the rod 80 is entirely removed therefrom.

The valve 70 is provided to control the flow of fluid directly in the string of tubing, after the rod 80 has been removed, so that any de sired arrangement of piping may be coupled to the string of tubing after the above operations have been carried out.

Prior to my invention it has been impossible to set tubing in some well casings due to the high pressures of the fluids existing in these wells. Any attempts to tube such wells have proven disastrous, and in many instances force to the tubing tending to force the tubing into the well casing, snubbing the tubing to prevent its movement out of the casing under the influence of said high pressures,

forming a temporary seal within the tubing to prevent the escape of said fluid from the casing through the tubing, forming a choke in the tubing after the tubing has been lowered into the casing, breaking the said temporary seal in the tubing to permit the fluid under pressure to flow therethrough to the choke, and subsequently breaking the choke to permit a full flow of said fluid through the tubing.

2. process for inserting tubing into well casings containing fluid under high pressures, said process comprising the application of force to the tubing tending to force the tubing into the well casing, snubbing the tubing to prevent its movement out of the casings under the influence of said high pressures, forming a temporary seal within the tubing to prevent the escape of said fluid from the casing through the tubing, forming a temporary seal between the tubing and the eas- 4' ing to prevent the escape of said fluid from the casing around the tubing, forming a choke in the tubing after the tubing has been lowered into the casing, breaking the said temporary seal in the tubing to permit the fluid under pressure to flow therethrough to the choke, forming a permanent seal between the casing and the tubing to prevent the escape of said fluid around the outside of the tubing, removing the said temporary seal previously formed between the casing and the outside of the tubing, and subsequently breaking the choke to permit a full flow of said fluid through the tubing.

3-. A processfor inserting tubing into well casings containing fluid under high pressures, said process comprising the application of force to the tubing tending to force the tub-- ing into the well casing, snubbing the tubing to prevent its movement out of the casings under the influence of said high pressures,

forming a temporary seal within the tubing to prevent the escape of said fluid from the casing through the tubing, forming a temporary seal between the tubing and the casing to prevent the escape of said fluid from the casing around the tubing, forming a choke in the tubing after the tubing has been lowered into the casing, breaking the said temporary seal in the tubing to permit the fluid under pressure to flow therethrough to the choke, forming a permanent seal between the casing and the tubing to prevent the escape of said fluid around the outside of the tubing, removing the said temporary seal previously formed between the casing and the outside of the tubing, piping the tubing above the said permanent seal for controlling the fluid to pass through the tubing, and subsequently breaking the choke to permit a full flow of said fluid through the tubing.

4. The method of inserting tubing in well casing containng fluid under high pressures, consisting in temporarily sealing the lower end of the tubing, forcing the same into the well, inserting a choke in the tubing above the seal, breaking the temporary seal and then breaking the choke.

5. The method of inserting a string of coupled sections of tubing into a well casing containing fluid under high pressure, consisting in sealing the lower end of the tubing and intermittently forcing the tubing into the casing in short steps by laterally-balanced pressure applied longitudinally of the tubing through positive gripping means applicable to the tubing sections intermediate the ends thereof.

6. The method of inserting a string of coupled sections of tubing into a well casing containing fluid under high pressure, consisting in sealing the lower end of the tubing and intermittently forcing the tubing into the casing in short steps by laterallybalanced pressure applied longitudinally of the tubing through positive gripping means applicable to the tubing sections intermediate the ends thereof,-placing a choke in the tubing adjacent the upper end thereof, breaking the seal of the lower end of the tubing and subsequently removing said choke.

7. The methodof inserting a string of coupled sections of tubing into a well casing containing fluid under high pressure, consisting in sealing the lower end of the tubing with a seal breakable upon an operation of the tubing abnormal to insertion thereof, intermittently forcing the tubing into the casing in short steps by laterally-balanced pressure applied longitudinally of the tubing, and performing said operation to break said seal.

8. The method of inserting a string of coupled sections of tubing into a well casing containing fluid under high pressure, consisting in sealing the lower end of the tubing with a seal breakable upon an operation of the tubing abnormal to insertion thereof, intermittently forcing the tubing into the casing in short steps by laterally-balanced pressure applied longitudinally of the tub ing, inserting a choke in the upper end of the casing, performing said operation to break said seal, and finally removing said choke.

9. In apparatus for tubing wells against high pressure in the well, a tubing having a seal at its lower end breakable upon an operation of the tubing abnormal to insertion thereof, and a choke in the tubing adjacent the upper end thereof.

10. Apparatus for tubing wells against high pressures, comprising a tubing to be inserted in a well casing, the tubing having a seal at its lower end breakable upon an operation of the tubing abnormal to insertion, said tubing comprising coupled sections, means to engage said sections intermediate the ends thereof and apply laterallybalanced longitudinally-directed pressure to the tubing to force the same into the well, and means to snub the tubing to prevent its movement out of the casing under the influence of high pressures.

11. Apparatus for tubing wells against high pressures, comprising a tubing to be inserted in a well casing, the tubing having a seal at its lower end breakable upon an operation of the tubing abnormal to insertion, said tubing comprising coupled sections, means to engage said sections intermediate the ends thereof and apply lateral ly-balanced longitudinally-directed pressure to the tubing to force the same into the well, means to, snub the tubing to prevent its movement out of the .casing under the infiuence of high pressures, a choke in the tubing at the upper end thereof, and means to break said seal while said choke is in position in the tubing.

. HERBERT G. OTIS.

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