Untitled record

Feb. 14, 1956 l. a. layne 2,734,580

METHOD AND APPARATUS FOR REPAIRING BROKEN CASING IN WELL BORES

Filed March 2, 1953 3 Sheets-Sheet 1

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Les//e A. Layne

INVENTOR.

ATTORNEY

Feb. 14, 1956 l. a. layne 2,734,580

METHOD AND APPARATUS FOR REPAIRING BROKEN CASING IN WELL BORES

Filed March 2, 1953 ³ Sheets-Sheet 2

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Leshe A. Layne INVENTOR.

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ATTORNEY

Feb. 14, 1956

L. A. LAYNE

2,734,580

METHOD AND APPARATUS FOR REPAIRING BROKEN CASING IN WELL BORES

Filed March 2, 1953

Sheets-Sheet 3

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Zej//e A. Layne INVENTOR.

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ATTORNEY

2,734,580

Patented Feb. 14, 1956

United States Patent Office

2,734,580

METHOD AND APPARATUS FOR REPAIRING BROKEN CASING IN WELL BORES

Leslie A. Layne, Houston, Tex.

Application March 2,1953, Serial No. 339,797

Claims. (Cl. 166—14)

The invention concerns a method and an apparatus for repairing broken casing, in place, in well bores.

It is an object of the invention to provide a method and means for realigning the portions of the casing immediately adjacent the break and for forming a rigid and secure joint permanently connecting the broken portions of the casing.

The invention contemplates a hydraulically expansible tool comprising a vertically disposed cylinder of smaller diameter than the inside diameter of the casing, the cylinder having a valved lower end and having a cylindrical wall section capable of being deformed outwardly by. the application of fluid pressure, which may be lowered into the casing to the point where the break occurs and thereafter expanded by fluid pressure whereby the portions of the casing immediately adjacent the break are realigned with each other.

The invention further contemplates a hydraulically expansible tool of the type described which may be used also as a cementing plug. The invention contemplates first realigning the portions of the casing immediately adjacent the break, in the manner described, and thereafter perforating the adjacent area of the casing, as well as the cylindrical wall section of the tool, and forcing cement into the annulus between the formation and the casing, thru the perforations.

An advantageous feature of the invention is that the portions of the casing immediately adjacent the break may be realigned, and thereafter the adjacent area of the casing may be perforated, and cement forced into the annulus between the formation and the casing, through the perforations, in a single operation, without removing the tool from the hole.

Another advantageous feature of the invention is that it permits the connecting tubing to be withdrawn from the well bore, after depositing cement therein as above described, while causing the cement to be maintained under hydraulic pressure during such period of time as may be required for the cement to set. Thereafter the excess cement is drilled from the inside of the casing, and the tool itself is likewise removed from the casing by drilling. If desired the cylindrical wall section of the tool may be left in place to reenforce the resulting joint.

The invention will be readily understood by referring to the following description and the accompanying drawing, in which:

Fig. 1 is a diagrammatic view in elevation showing the broken casing, with a tool embodying the invention about to be lowered into position for repairing the break in the casing.

Fig. 2 is a diagrammatic view in elevation showing the tool in operative position, the tool being rotated 180 degrees from the position shown in Fig. 1 whereby its tapered lower end may be readily inserted in the lower portion of the casing, which may not be aligned with the upper portion.

Fig. 3 is a sectional view in elevation showing the cy- lindrical wall section of the tool in expanded position and the adjacent portions of the casing in alignment with each other.

Fig. 4 is a sectional view in elevation showing the step 5 of perforating the adjacent area of the casing and the cylindrical wall section of the tool.

Fig. 5 is a sectional view in elevation showing the step of forcing cement into the annulus between the casing and the formation, through the perforations.

Fig. 6 is a sectional view in elevation showing the step of drilling the excess cement, and the tool itself, from the inside of the casing.

Fig. 7 is a sectional view in elevation showing a modified form of the apparatus shown in Figs. 1 to 6, in15 elusive.

Fig. 8 is a sectional view in elevation, taken at right angles to the view shown in Fig. 7, showing the connecting tubing detached from the remainder of the apparatus.

Referring to the drawing, a broken casing is shown dis20 posed in a well bore. The well bore is designated by the numeral 1 and the portions of the casing above and below the break are indicated by the numerals 2 and 3, respectively. As shown in Fig. 1, the portions 2 and 3 are not aligned with each other.

The hydraulically expansible tool of the invention comprises a vertically disposed cylinder having a diameter smaller than the inside diameter of the casing, the cylinder having a valved lower end, as hereinafter described, and a cylindrical wall section which is capable of being 30 deformed outwardly by the application of fluid pressure.

The cylindrical wall section, designated by the numeral 4, may be made of a suitable metal or alloy, such as mild steel or aluminum, which may be deformed under pressure without bursting. The lower end of the cylinder is 35 at least partly closed by an end member 5, which is secured to the cylindrical wall section 4 and has a central opening 6 formed therein for the circulation of drilling fluid. The inner surface of the end member 5 is curved downwardly and inwardly adjacent the central opening 6 40 to form a valve seat for a ball valve 7, which may be dropped into the cylinder from the surface.

The upper end of the cylindrical wall section 4 is connected to a cylindrical wall section 8. The cylindrical wall section 8 is made of a metal or alloy having a greater 45 tensile strength than the cylindrical wall section 4, so that it retains its shape while the cylindrical wall section 4 is being expanded.

For use in setting the tool in the well, and for other purposes as hereinafter described, the cylindrical wall 50 section 8 is detachably secured to the lower end of a string of tubing 9. A collar 10 is secured to the lower end of the tubing 9, and a sealing ring 11, which is connected to the lower end of the collar 10 and extends downwardly and outwardly therefrom for engagement 55 with the cylindrical wall section 8 whereby a fluid tight connection is maintained between the collar 10 and the cylindrical wall section 8. A pair of diametrically opposed pins 12 extend outwardly from the collar 10 for engagement by a pair of J-shaped slots 13 which are 60 formed in the cylindrical wall section 8, adjacent the upper edge thereof, whereby the cylindrical wall section 8 is detachably secured to the collar 10.

As illustrated in Figs. 1, 2 and 3, the tapered end member 5 serves as a guide for inserting the tool in the lower 65 portion 3 of the casing, which may not be aligned with the upper portion 2. The tool is lowered in the casing to the point where the break occurs, and is disposed partly within the upper portion 2 and partly within the lower portion 3 of the casing. The ball valve 7 is seated, and 70 fluid pressure is applied to the tool, through the tubing 9, whereby the cylindrical wall section 4 is expanded so that it engages the walls of the casing above and below the

2,734,580 break, causing the portions 2 and 3 to be realigned with each other. Upon releasing the pressure the cylindrical wall section 4 retains the portions 2 and 3 in their proper relative positions.

As illustrated in Fig. 4, a perforating gun 14 may be 5 lowered into the well on a wire line 15, through the tubing 9, so that it is disposed within the tool above described. Upon discharging the gun 14 perforations 16 may be formed in the adjacent area of the portions 2 and 3 of the casing, as well as in the cylindrical wall section 4, the 10 perforations 16 extending also into the formation surrounding the well bore 1.

As illustrated in Fig. 5, the perforating gun 14 may be withdrawn and cement may be forced under pressure into the annulus between the well bore 1 and the portions 2 15 and 3 of the casing, through the perforations 16. Cement is supplied to the tool through the tubing 9, and the cement preferably is maintained under hydraulic pressure for a period of from 24 to 72 hours, until the cement sets.

As illustrated in Fig. 6, the tubing 9 is finally with- 20 drawn and the excess cement is drilled from the inside of the casing, using a suitable tool 17. The cylindrical wall sections 4 and 8, and the end member 5, likewise may be removed from the casing by drilling. If desired the cylindrical wall section 4 may be left in place to re- 25 enforce the resulting joint.

Referring to Figs. 7 and 8, a back pressure valve as described and claimed in the application of Louis C. Mundt, Serial No. 305,493, filed August 20, 1952, is incorporated in the apparatus. The back pressure valve 30 comprises a resilient, tubular body member 18, one end of the body member 18 being secured to a rigid annular member 19 and an elastic, self sealing opening 20 being formed in the end of the body member 18 opposite the annular member 19. The annular member 19 is secured 35 to the cylindrical wall section 4 adjacent the point where the cylindrical wall sections 4 and 8 are connected, and the arrangement is such that the lower end of the tubing 9, below the collar 10, may be inserted through the elastic, self sealing opening 20. This arrangement permits the 40 tubing 9 to be withdrawn, as shown in Fig. 8, immediately following the step of forcing cement into the annulus between the bore of the well and the casing, while maintaining the cement under substantial fluid pressure until sufficient time has elapsed to cause it to set. 45

The invention may be modified in various ways without departing from the spirit and scope thereof.