US2970470A

US2970470A - Method and apparatus for use in wells

Info

Publication number: US2970470A
Application number: US717071A
Authority: US
Inventors: John W Kenneday
Original assignee: Jersey Production Research Co
Current assignee: Jersey Production Research Co
Priority date: 1958-02-24
Filing date: 1958-02-24
Publication date: 1961-02-07
Anticipated expiration: 1978-02-07

Description

QEARQH WW2 Feb. 7, 1961 J, w. KENNEDAY METHOD AND APPARATUS FOR USE IN WELLS Filed Feb. 24, 1958 2 SheetsSheer. 1

FIG. I. 32\ 3 FIG. 2.

FIG. 3.

INVENTOR. JOHN W. KENNEDAY,

A T TORNE Y.

Feb. 7, 1961 J. w. KENNEDAY METHOD AND APPARATUS FOR USE IN WELLS 2 Sheet-Sheet 2 Filed Feb. 24. 1958 m m M ATTORNEY.

United States Patent METHOD AND APPARATUS FOR USE IN WELLS John W. Kenneday, Houston, Tex., assignor, by mesne assignments, to Jersey Production Research Company, Tulsa, Okla., a corporation of Delaware Filed Feb. 24, 1958, Ser. No. 717,071

7 Claims. (Cl. 73151) This invention relates to oil and gas wells. More particularly this invention relates to a method and apparatus for pressure testing the seals and tubing used in carrying out oil and gas production utilizing a tubing string permanently arranged within a well and a tubing extension.

One method of carrying out operations in oil and gas wells is to first provide a casing on the sides of the well and then provide a permanently arranged tubing string with its lower extremity located above the uppermost producing formation. An extension member is then lowered down the permanently arranged tubing and secured in position by means of a locking means which engage a landing nipple provided in the tubing. The tubing and extension member form a continuous passageway from the producing formations to the earths surface for oil and gas production or for placement and removal of treating materials.

Before operations are begun, however, it is desirable that a pressure test he made on the tubing, packing, and extension suspension member to be certain that there are no pressure leaks in the tubing, extension suspension member, or the packers used to pressure seal various parts of the arrangemnet. For example, a sealing means such as chevron packing is usually included on the extension member to provide a pressure seal between the extension and the tubing. When this pressure seal is eflected, fluids can be made to flow down the tubingcasing annulus and up the inside of the tubing extension and tubing to the earths surface; or fluids can be made to flow down the tubing through the tubular extension passageway and on up the tubing-casing annulus to the surface.

To pressure test, however, it is necessary to plug the tubular extension passageway. This is often done by means of a running tool having thereon a solid pressure testing prong.. Pressure can then be applied down the tubing-casing annulus. Since the plug is located in the tubing extension passageway, no pressure is received at the earths surface unless it leaks through the packing or the tubing. In the alternative, pressure can be applied down through the permanently arranged tubing and again, since the tubing extension passageway is plugged, no pressure will be received between the tubing-casing annulus unless the packer or tubing has developed a leak.

After the pressure test has been made, it is necessary to remove the plug or pressure testing prong to equalize the pressure within the tubular extension passageway and the pressure between the tubular extension and the perma- ICE nently arranged tubing. However, the removal of the testing prong is often very difficult and even impossible because of a greater hydrostatic head of fluids contained within the tubing. This greater hydrostatic head of fluids within the tubing may occur during pressure testing operations it the formation open to the well bore through the casing perforations will not support a fluid column weight in the tubing-casing annulus equivalent to the fluid column weight in the tubing. This greater hydrostatic pressure of the fluids contained within the tubing tends to hold the testing prong in place, and before the prong can be removed, the tension or force used to extract the prong must be great enough to overcome the retaining force, which is approximately the sum of the shear pin shear strength plus a force equal to the difierence of hydrostatic pressures above and below the prong, multiplied by the cross-sectional area of the prong.

This invention provides a new and novel method and apparatus for carrying out pressure testing of the tubing and sealing means. By utilizing this method and apparatus, the pressure tests can be made and the pressure within the tubular extension member passageway equalized with the hydrostatic tubing pressure above the prong prior to the removal of the pressure testing prong. By utilizing the method and the apparatus to be hereinafter described, it is not necessary that the force retaining the prong as a result of a greater tubing hydrostatic head be overcome by an equivalent or greater force before the testing prong can be removed to the earths surface.

Briefly described, the system described herein includes an extension member having a continuous passageway formed therein. The extension member is adapted to be secured to the stationary tubing. Means are provided for isolating the pressure within the tubular extension member below the isolating means and the pressure within the tubing above the isolating means or testing prong. After the pressure test has been made, means responsive to upward movement of the running tool equalizes the pressure within the tubular extension member and the hydrostatic head. This permits the easy removal of the testing prong, which is of special construction.

A better understanding of this invention, as well as its advantages, may be had by reference to the following detailed description and drawings, in which:

Fig. 1 is an elevational view showing the arrangement of various tools which may be used in practicing the invention;

Fig. 2 is an elevational sectional view showing in detail the pressure testing and equalizing device and the initial position of the parts as the device is lowered into the well;

Fig. 3 is a sectional elevational view showing the parts as the extension member is being locked and secured to the permanently arranged tubing;

Fig. 4 is a sectional elevational view showing the arrangement of the parts after the well has been pressure tested and the pressure within the tubular extension has been equalized with the pressure within the tubing; and

Fig. 5 is a sectional elevational view showing the running tool and the pressure testing and equalizing device being removed from the well.

Referring specifically to Fig. 1, a borehole 10 is shown. The usual casing 12 is cemented to the sides of the borehole 10.

Permanently arranged within the borehole 10, having its lower extremity above producing formation 14, is a tubing string 16. Tubing string 16 has provided therein recesses such as a landing nipple 18 for receiving dogs 20 provided in a tubular extension member 22.

The dogs 20 are located in the tubular extension member hanger assembly 24. Located above the hanger assembly 24 and connected together are a running tool 26, weight 28, jarring tool 30, and a second weight 32, connected to a wire line 34. Fluid ports 36 are formed in the running tool 26.

A packing 40 is located about the extension member 22 at a point below the dogs 20. Therefore, when the packing 40 is set against the inside of permanent tubing 16, fluid flow down the tubing-casing annulus must pass up the extension member 22, out of fluid ports 36,

and then to the surface. Or if desired, the fluid flow might be applied down the tubing 16 and through the fluid ports 36, extension member 22, and then up the tubing-casing annulus to the earths surface.

To make a pressure test of the packing 40 and tubing 16, the passageway in tubular extension 22 is plugged conventionally by a prong. The plugging of the passageway in tubular extension 22 of course prevents the flow of fluid through the passageway so that any pressure ap- 'hanger assembly 24 and the tubular extension member 22 locked to the permanently placed tubing 16.

The testing prong must also be removed to provide a continuous passageway for the production of oil and gas from producing formation 14. However, the removal of this pressure testing member in a conventionally used system is often very difficult and sometimes impossible due to the greater hydrostatic pressure head within the tubing 16. This greater hydrostatic head pressure within the tubing may often exceed the hydrostatic head pressure within the extension by as much as 2000 pounds per square inch.

Fig. 2 shows in sectional view the running tool and pressure testing and pressure equalizing mechanism used in the present invention. The running tool 26 includes a sleeve 42 through which the ports 36 are formed. Thus, a hollowed out portion 44 is formed in the lower portion of the running tool 26.

An outwardly extending collar 46 is located at the lower extremity of sleeve 42, and a circular shoulder 48 is formed on the inside of sleeve 42 upwardly from the bottom of the sleeve.

The sleeve 42 is releasably connected by means of shear pins 50 to a fishing neck 52 forming part of the extension member 22. An extension hanger expander sleeve 54 is integrally connected to the fishing neck 52, which, upon downward movement, forces out the dogs 20 into locking engagement with the nipple of the permanent tubmg.

The pressure testing prong 56 is disposed within sleeve 42, with the lower portion thereof extending into the continuous passageway 58 of the extension member 22, the lower portion being releasably connected to mandrel 59 by shear pin 66. Thus, prong 56 initially isolates the pressure within passageway 58 from the hydrostatic head pressure above the running tool and within the hollow space 44. Prong 56 is generally cylindrical in shape and has a larger diameter portion 60 at its upper most extremity. A bore is formed in prong 56 and extends upwardly from its lower end and terminates within the prong at a point above fluid ports 64.

A pressure equalizing sleeve 68 is releasably mounted about the pressure testing prong 56 and normally surrounds the fluid ports 64 to isolate the pressure within the bore 62 and passageway 58 from the pressure within the running tool hollow space 44. The pressure equalizing sleeve 68 is releasably connected to the testing prong 56 by means of shear pins 70 extending through the testing prong 56 and larger diameter portion 72 of the equalizing sleeve 68.

Grooves

74 and 76 are formed above and below, re-

spectively, the fluid ports 64 and contain O-

rings

78 and 80 to permit pressure-tight sliding movement of the pressure equalizing sleeve 68 with respect to the pressure testing prong 56. A circular groove 82 is formed adjacent the lower extremity of the testing prong 56 and contains an O-ring 84 for permitting pressure-tight slidable movement of the testing prong 56 with respect to the inside of the extension member 22.

Y A spacer sleeve 86 is shear pinned to the outside perimeter of sleeve 42 by means of shear pins 88. Spacer sleeve 86 has a downwardly facing shoulder 92 which is adapted for mating engagement with the collar 46 formed on the sleeve 42. The lower extremity of spacer sleeve 86 initially rests upon the top of extension member 22, as shown in Fig. 2.

In carrying out my new method, the running tool and extension member are run down the permanently placed tubing 16, with the parts in the positions as shown in Fig. 2. When the extension member 22 is properly placed, the running tool 26 is jarred downwardly by jarring tool 30 (see Fig. 1) to shear the shear pins 88 and 50. This permits circular shoulder 48 to move down and engage fishing neck 52. Continued jarring moves fishing neck 52 and expander sleeve 54 downwardly to wedge out the locking dogs 20 into the landing nipple 18 of permanent tubing string 16. The positions of the members are then as shown in Fig. 3. As shown in Fig. 3, the circular shoulder 48 has been jarred against fishing neck 52 to move fishing neck 52 and expander sleeve 54 downwardly with respect to mandrel 59. The spacer sleeve 86 continues to rest upon the body of tubular extension member 22. However, the collar 46 has been lowered from its mating engagement with downwardly facing shoulder 92.

The extension member is now firmly locked in position. A pressure test can now be made of the tubing and casing. As formerly stated, this pressure test is accomplished by applying pressure either downwardly in the tubing-casing annulus or downwardly in the tubing 16. The pressure test will indicate whether the packer 40 and the tubing 16 is pressure tight.

After the pressure test has been made, it is desirable to remove the running tool 26, the testing prong 56, and

the pressure equalizing sleeve 68. Because of the greater hydrostatic pressure acting from within the tubing 16 against the pressure testing prong 56, it is very difiicult 'to remove the prong from the extension member 22.

This is because of the great pressure differential across the prong 56. However, since sleeve 42 has the pressure ports 36 formed therein, pressure ports 36 place the hollow portion 44 of the sleeve 42 in pressure communication with the hydrostatic head within the tubing 16. Hence, the pressure working upwardly against the running tool 26 is substantially equal to the pressure working downwardly. Thus, running tool 26 can be very easily moved upwards.

Upward movement of running tool 26 causes circular shoulder 48 to engage the larger diameter portion 72 of equalizing sleeve 68 to shear the shear pin 70. The up ward movement of equalizing sleeve 68 exposes the fluid ports 64 formed in prong 56 to place the bore 62 and passageway 58 into pressure communication with the hydrostatic head within the tubing 16. The relative positions of the parts are then as shown in Fig. 4.

The upward movement of the running tool 26 also causes collar 46 on the lower extremity of sleeve 42 to matingly engage the downwardly facing shoulder 92 of spacer sleeve 86 to carry the spacer sleeve 86 upwardly along with the running tool 26. The exposure of fluid ports 64 causes the pressure'within the extension member passageway 58 and bore 62 to be substantially equal to the hydrostatic head pressure within tubing 16. Hence, no pressure differential exists across the prong 56 and it can now be very easily removed to the surface.

The removal of the prong 56 from the extension member is accomplished by continued upward movement of running tool 26. This is shown in Fig. 5. Shear pin 66 is sheared to release the lower portion of testing prong 56 from the inside of extension member 22. This is accomplished after the larger diameter portion 72 of equalizing sleeve 68 has been moved upwardly into engagement with the larger diameter portion 60 of testing prong 56. Hence, the running tool 26, testing prong 56, equalizing sleeve 68, and spacer sleeve 86 are all removed to the earths surface by means of wire line 34, leaving the extension member 22 firmly locked in position within the permanent tubing 16. Passageway 58 in extension member 22 now forms a continuous passageway with the tubing 16. The production of oil and gas, as well as workover operations, may no be performed.

Although a specific apparatus has been described for carrying out the described method, it is to be understood that various other apparatus may be used for carrying out the method.

I claim:

1. A system for use in a cased well having a tubing string permanently arranged therein with its lower extremity above producing formations comprising: a running tool, said running tool have a hollowed out portion extending upwardly from the lower extremity thereof and in fluid communication with the hydrostatic head within the tubing string; a tubular extension member having a continuous passageway formed therein releasably connected to the running tool; packing means mounted on the extension member for setting against the tubing string; means for isolating the pressure within the tubular extension member from the hydrostatic head within the tubing string against pressure applied from any direction to permit pressure testing of the packing means; and means responsive to upward movement of the running tool for equalizing the pressure within the tubular extension member with the hydrostatic head within the tubing string.

2. A system for use in a cased well having a tubing string permanently arranged therein with its lower extremity above producing formations comprising: a running too], said running tool having a hollowed out portion extending upwardly from the lower extremity thereof and in fluid communication with the hydrostatic head within the tubing string; a tubular extension member having a continuous passageway formed therein releasably connected to the running tool; packing means mounted on the extension member for setting against the tubing string; a prong member having at least one port therein adapted to be placed in fluid communication with said hollowed out portion of the running tool; and a sleeve member mounted about the prong member and initially covering said port, said sleeve member being responsive to upward movement of the running tool to place said port in fluid communication with the hollowed out portion of the running tool.

3. A system in accordance with claim 2 wherein the prong member has a larger diameter portion adapted to be contacted by the sleeve member after said port has been placed in communication with the hollowed out portion of the running tool so that the prong member may be raised to the surface of the earth with the running tool.

4. For use in a cased well including stationary tubing having its lower end arranged above producing formations: an extension member having a continuous passageway formed therein adapted to be secured to the stationary tubing; a pressure testing prong having at least one fluid port formed therein in communication with the extension member passageway; a sleeve closing said fluid port to isolate the pressure within said extension member passageway from the hydrostatic head within the tubing against pressure applied from any direction; and means for moving said sleeve to open said fluid port thus permitting easy removal of the pressure testing prong to the earths surface.

5. For use in a cased well including stationary tubing having its lower end arranged above producing formations: a running tool including a sleeve member having an open lower end with fluid ports formed in said sleeve; a shoulder formed on the inside of said sleeve; an extension member having a continuous passageway formed therein releasably connected to said sleeve, means for firmly positioning the extension member within the stationary tubing; a cylindrical pressure testing prong having a larger diameter portion and at least one fluid port formed therein releasably connected to the inside of said extension member; and means for normally closing said fluid port to isolate the pressure within the extension member from the hydrostatic head within the tubing against pressure applied from any direction, said means being responsive to upward jarring of the running tool to open said fluid port whereby successively the extension member can be firmly positioned within the tubing, a pressure test of the tubing and easing made, the pressure within the extension member equalized with the hydrostatic head within the tubing, and the running tool and prong removed from the well.

6. For used in a cased well including stationary tubing having its lower end arranged above producing formations: a running tool including a sleeve member having an open lower end with fluid ports formed in said sleeve; a circular shoulder formed on the inside of said sleeve; an extension member having a continuous passageway formed therein releasably connected to said sleeve; means for firmly positioning the extension member within the stationary tubing; a cylindrical pressure testing prong having a larger diameter portion, a bore formed upwardly from its lower end terminating within the prong, and fluid ports formed therein in communication with the bore releasably connected to the inside of said extension member; and a pressure equalizing sleeve releasably mounted about said pressure testing prong and normally surrounding the fluid ports in the prong to isolate the pressure within said bore, and having a larger diameter portion adapted to successively be contacted by said circular shoulder and then contact said larger diameter portion of the pressure testing prong as the running tool is jarred upwards whereby successively the extension member can be firmly positioned within the tubing, a pressure test of the tubing and easing made, the pressure within the extension member equalized with the hydrostatic head within the tubing, and the running tool, prong, and equalizing sleeve removed from the well.

7. For use in a cased Well including stationary tubing having its lower end arranged above producing formations: a running tool including a sleeve member having an open lower end with fiuid ports formed in said sleeve; a circular shoulder formed on the inside of said sleeve upwardly from the bottom of said sleeve; an extension member having a continuous passageway formed therein releasably connected to the inside of said sleeve with its upper extremity below said circular shoulder; locking means responsive to jarring of the shoulder against the top of the extension member to firmly position the extension member to firmly position the extension member within the stationary tubing; a cylindrical pressure testing prong having a larger diameter portion at its uppermost extermity, a bore formed upwardly from its lower end terminating within the prong, and fluid ports formed therein in communication with the bore, releasably connected to the inside of said extension member; and a pressure equalizing sleeve releasably mounted about said pressure testing prong and normally surrounding the fluid ports in the prong to isolate the pressure within said bore from the hydrostatic pressure within the tubing and having a larger diameter upper portion adapted to successively be contacted by said circular shoulder and then contact said larger diameter portion of the pressure testing prong as the running tool is jarred upwards whereby successively the extension member can be firmly locked within the tubing, a pressure test of the tubing and casing made, the pressure within the extension member equalized with the hydrostatic head within the tubing, and the running too], prong, and equalizing sleeve removed from the well.

References Cited in the file of this patent UNITED STATES PATENTS 2,742,093 Vaughn Apr. 17, 1956 10 2,798,559 Fredd -2 July 9, 1957 2,909,221 Bostock Oct. 20, 1959