US3693715A

US3693715A - Apparatus for blocking fluid flow in a well casing

Info

Publication number: US3693715A
Application number: US143406A
Authority: US
Inventors: John M Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-05-14
Filing date: 1971-05-14
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26

Abstract

Apparatus for blocking fluid flow in a well casing where the well is out of control due to blowout, fire or casing leaks. A shell comprised of two hingedly connected mating parts is mounted on the casing so as to enclose a portion thereof in a sealed manner. A metal cutting saw blade in the shell is provided with power means to reciprocate it and move it into the casing whereby the blade cuts through the casing. The width of the blade is greater than the casing diameter so that upon completion of the cut the blade blocks the fluid flow. This permits a shut off valve or other control means to be installed in the casing above the shell after which the saw can be withdrawn and the shell removed for re-use.

Description

United States Patent Brown 51 Se t. 26, 1972 [54] APPARATUS FOR BLOCKING FLUID FLOW IN A WELL CASING [72] Inventor: John M. Brown, 5787 Pine Grove Road, R.D. 3, Clay, N.Y. 13041 [22] Filed: May 14, 1971 [21] Appl. No.: 143,406

[52] US. Cl .166/55, 166/93 [51] Int. Cl. ..E2lb 29/00 [58] Field of Search ..166/55, 55.1, 297, 298, 92, 166/93; 251/] [56] References Cited UNITED STATES PATENTS 1,803,945 5/1931 Retherford et a1. ..166/93 1,851,894 3/1932 Clough ..l66/55 2,969,838 l/1961 Wilde 166/55 3,379,255 4/1968 Burns et al 166/55 3,561,526 2/1971 Williams et a1 ..l66/55 3,590,920 7/1971 Orund et al 166/55 Primary Examiner-David H. Brown AtlomeyBruns & Jenney [57] ABSTRACT Apparatus for blocking fluid flow in a well casing where the well is out of control due to blowout, fire or casing leaks. A shell comprised of two hingedly connected mating parts is mounted on the casing so as to enclose a portion thereof in a sealed manner. A metal cutting saw blade in the shell is provided with power means to reciprocate it and move it into the casing whereby the blade cuts through the casing. The width of the blade is greater than the casing diameter so that upon completion of the cut the blade blocks the fluid flow. This permits a shut off valve or other control means to be installed in the casing above the shell after which the saw can be withdrawn and the shell removed for re-use.

10 Claims, 8 Drawing Figures PAIENTEDsErzs m2 SHEET 2 [1F 3 INVENTOR. JOHN M. BROWN ATTORNEY' minnows Ian SHEEI 3 UP 3 INVENTOR. JOHN M. BROWN ATTORNEYEfi' APPARATUS FOR BLOCKING FLUID FLOW IN A WELL CASING BACKGROUND OF THE INVENTION This invention relates generally to well drilling equipment, and has particular reference to novel apparatus for blocking the fluid flow in a well casing where the well is out of control due to blowout, fire or casing leaks.

As is.well known, an out of control hydrocarbon well can cause'enormous damage by pollution as well as a substantial economic loss due to the escape or destruction of the oil or gas. Many devices and methods have been developed for solving this ever-present problem but often the proposed solutions are in themselves hazardous and uncertain of success. Other proposed solutions, while perhaps safer and surer, are very complex and expensive.

Particular difficulty has been encountered in offshore drilling operations where well malfunctions are complicated by the surrounding water and escaping oil can severely pollute beaches and kill untold numbers of sea birdsand fish. To the best of applicants knowledge, no practical and effective means has heretofore been developed for coping with an offshore well that is malfunctioning.

SUMMARY OF THE INVENTION The apparatus of the present invention is particularly adapted for blocking the .flow of the fluid in an offshore well casing, but it will be apparent as the description proceeds that it can also be advantageously utilized for on-shore oil or gas wells.

The apparatus comprises a hollow shell or capsule which is constructed so that it can be mounted, as by divers, on a well casing to enclose a portion of the casing in a sealed manner. The shell contains a carriage that is movable towards and away from the casing, and a metal cutting saw blade is mounted on the carriage for reciprocating movement relative to the casing. Power means are provided to reciprocate the saw and this in turn causes the carriage to advance toward the casing whereby the latter is cut by the saw.

The width of the saw blade is greater than the diameter of the well-casing and upon completion of the cut, means are actuated which stop the saw and carriage movement whereby the saw blade spans the inner diameter of the casing and blocks the flow of fluid therein. This allows workers to install a shut off valve or other control device at a pointabove the shell, and after this has been done the saw blade is withdrawn from the casing by means operable from outside the shell.

In the shell interior there is also a sleeve assembly that is releasably held on the casing above the plane of the saw blade. After the blade has been withdrawn from the casing, this sleeve is permitted to slide down on the casing so that it encircles the saw cut. The sleeve can then be secured in this position so that it seals the cut, the flow now being controlled by the valve that was installed above the shell when the saw blade blocked the fluid flow. This enables the shell to be removed from the casing for re-use, except for the sleeve which is left to seal the saw cut.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diminutive front elevation of a fluid flow blocking apparatus embodying the invention;

FIG. 2 is a diminutive left side elevation thereof;

FIG. 3 is a diminutive top plan view thereof;

FIG. 4 is a front elevation of the apparatus with the hinged mating parts in open position as the apparatus is being mounted on the well casing;

FIG. 5 is a vertical sectional view taken on line 55 on FIG. 3;

FIG. 6 is a horizontal'sectional view taken on line 6-'- 6 of FIG. 4;

FIG. 7 is an enlarged vertical sectional view of a detail of the construction taken on line 77 of FIG. 6; and

FIG. 8 is an enlarged vertical sectional view of a detail taken on line 8-8 of FIG. 6.

DESCRIPTION OF THE 'PREF ERRED EMBODIMENT Having reference now to the drawings,and with particular reference to FIGS. 1-3, the fluid flow blocking apparatus of the invention is indicated generally by the reference number l0and is shown mounted on a well casing 11. In the description to follow, the apparatus is described in conjunction with an off-shore well wherein the casing 11 is under water but it will be apparent as the description proceeds that the apparatus can be employed with equal effectiveness with on-shore well casings in oil or gas wells.

The flow blocking apparatus 10 is in the form of a hollow shell comprised of two

mating parts

12,14 hingedly connected together along a vertical edge as at 15. Each mating part is formed with upper and lower vertically aligned semi-cylindrical bosses 16 which permit the parts when closed to fit around'the casing 11 and enclose a portion 17 thereof, FIG. 5, within the shell in a sealed manner. To this end, the

parts

12 and 14, which are of relatively heavy gauge metal, are formed with mating

peripheral flanges

18,19 adapted to be bolted together as by bolts 20 with a sealing gasket (not shown) therebetween. In addition, the bosses 16 are provided on their inner surfaces with a plurality of mating, semi-annular knife edged ridges 21 that bite into the casing and help form a seal. between it and the shell. The shell, which may be 4-6 feet across and equally high, is lowered into position by cable from a boat on the surface, the cable or cables being secured to eyes 22 welded to the top of the shell. The shell is mounted on the casing 11 by divers at a point, for example, several feet below a leak. To this end, the part 12 of the shell is' provided with a relatively heavy vertical stanchion 24 rigidly secured to the top and bottom of the part and formed with upper and

lower projections

25,26 having semi-annular recesses 27 for receiving the casing therein. Between the

projections

25 and 26, the stanchion is formed with a pair of spaced arms. 28, FIGS. 4 and 5, which also have semi-annular recesses for-receiving the casing as indicated at 29 in FIG. 5.

With the shell parts in open position as shown in FIG. 4, the part 12 is brought into engagement with the casing so that the latter is positioned in the recesses of the

projections

25,26 and arms 28, and semi-annular brackets or clamp members 30 are then bolted to the arms to rigidly secure the part 12, and thus the complete shell, in position on the casing. Thereafter, the part 14 is swung into engagement with part 12 and the shell is closed by bolting the mating flanges l8 and 19 together with a gasket therebetween as described above.

The other shell part 14 is provided with a carriage 31 in the form of a flat plate member that is movable towards and away from the casing, the carriage being slidable on a supporting plate 32 and guided by ways 34, FIG. 4. A heavy metal cutting saw blade .35 is mounted on the carriage for reciprocating movement relative thereto and to the casing, the saw being slidably supported at its reduced end portions 36 by supports 37 secured to the carriage as. best shown in FIGS. 4 and 6. It is an important feature of the invention that the width of the toothed central portion 38 of the saw blade is greater than the outside diameter of the casing 11.

In accord with the invention, means are provided to reciprocate the saw and at the same time advance the carriage 31 towards the casing so that the saw cuts through the latter and upon completion of the cut blocks the flow of fluid in the casing because of its width. The saw blade reciprocation is effected by an electric motor 39, FIG. 4, located in a sealed, fluidtight housing 40, the motor having a power connection 41 to a fitting 42 on the exterior of the shell, FIG. 1. The fitting 42 includes an on-off switch and a receptacle for a power cable from the boat above, the fitting components being sealed against the water in a manner known in the art.

The motor 39 operates through a gear train 44 to actuate a crank mechanism 45 and reciprocate the saw blade. This permits the saw to make in the order of 90 strokes per minute with the cutting being done in the pushing direction. In this connection, proper functioning of the saw is aided by off-setting its longitudinal axis 'a very small amount out of parallelism with the straight front edge 46 of the carriage 31, FIG. 6. This offset, which may be no more than 1-20 between the saw axis and edge 46, positions the right end of the saw blade slightly farther away from the edge than the left end as shown in FIG, 6 with the cutting taking place as the saw moves from right to left on the push stroke.

Movement of the carriage 31 to advance the saw blade intov the casing is effected by the reciprocating movement of the saw itself. This is accomplished by the engagement of a ratchet tooth 47 carried by the saw with a pinion 48 fixed on the end of, a horizontal shaft 49, FIGS. 6 and 8. The tooth 47 is pivotally connected to a bracket 50 mounted on the rear edge of the central portion 38 of the saw and is arranged to engage and turn the pinion a few degrees on each push stroke of the saw. Thus, as viewed in FIG. 8 looking at the back of the saw blade, on movement of the saw to the right during a push stroke the tooth 47 drives the pinion since it is held against pivoting by a stop 51 on the bracket 50. In FIG. 8, the blade is shown at the end of a push stroke. On the return or pull stroke in the opposite direction, the ratchet tooth is allowed to pivot and simply passes over the pinion without engagement.

The shaft 49 extends from the pinion 48 out through the wall of the shell, passing through a fitting 52 in the shellpart 14, FIG. 5. Adjacent the fitting, the shaft is formed with a screw thread 54 that meshes with a corresponding internal thread (notshown) in the fitting, the fitting also being provided with a packing gland 55 or the like. With this construction, the rotation of the pinion 48 by ratchet tooth 47 causes the shaft 49 to move longitudinally towards the casing.

Shaft 49 is connected to carriage 31 by a bearing connection shown in FIGS. 6 and 7. In this connection, the inner race 56 of a roller or ball bearing is fixed on the shaft as by a press fit while the outer race 57 is fixed as by a set screw 58 in a support 59 secured to the carriage. Withv this arrangement, the carriage, and consequently the saw blade, will move with the shaft so that the saw will be advanced into the casing as it reciprocates. To enable the carriage to travel far enough for the saw to cut all the way through the easing, the carriage is formed with an elongated central cut-out 60 so that it can in effect straddle the casing as it moves forward. The carriage supporting plate 32, which is fixed, is also provided with a central cut-out 61 to accommodate the casing as shown in FIG. 6.

When the saw blade has out completely through the casing, the carriage will have advanced to the position indicated by phantom lines at 62 in FIG. 5 where it engages a limit switch 64 that shuts off the motor. At this time, the saw because of its width spans the casing and blocks the further flow of fluid therein. With the fluid flow blocked, diver workmen can install a shut off valve (not shown) or other control means between the top of the shell and the leak. Thereafter, the saw is withdrawn from the casing which can be done manually from outside the shell by turning a handwheel 65 on the outer end of shaft 49 until the carriage reaches the limit of its rearward movement indicated by phantom lines at 66 in FIG. 5.

When the shell is first mounted on the casing as indicated in FIG. 4, and before the two parts are closed and bolted together, a sleeve assembly 67 is also mounted on the casing between the arms 28 and above the plane of the saw blade, the centerline of the saw cut in the casing being shown at 68 inFIG. 4. This sleeve assembly comprises a pair of mating

semi-cylindrical members

69,70 that fit around the casing and are secured together by nuts and bolts that pass through abutting side flanges 71 on the members. In installing the assembly on the casing, the nuts (not shown) are tightened just enough to hold the assembly in the position shown in FIGS. 4 and 5. I

The heads 72 of the bolts are welded to the semicylindrical member 69 and after tightening the nuts as above described, wrench sockets 74 are positioned on the nuts, each socket being pivotally connected ,to a shaft 75 telescopically received in one end of a tube 76. At their opposite ends, the tubes are pivotally connected to bolts 77 which pass throughtapped holes in a plate 78 in the wall of the shell part 12 so that the heads of the bolts are outside the shell. Relative rotation between shafts 75 and tubes 76 is prevented as by keying.

After the saw blade has made its cut and has been manually withdrawn from the casing by means of the handwheel 65, and with the shell still closed, the bolts 77 are turned from outside the shell which loosens the nuts on the sleeve assembly 67. This permits the sleeve to slide down on the casing under its own weight until the bottom of the sleeve rests on the supporting plate 32, this position of the sleeve being indicated by phantom lines at 79 in FIG. 4. As the sleeve slides down on the casing, the shafts 75 for the sleeve nuts move farther into the tubes 76 to compensate for the shortening of the distanceb'etween the sleeve and the actuating bolts 77.

With the sleeve assembly resting on the plate 32, it will be apparent from FIGS. 4 and 5 that it encircles the saw cut made in the casing. Once in this position, the sleeve nuts are tightened from outside the shell by means of the bolts 77 whereby the saw cut is substantially sealed. Thereafter, the shell is opened to the position shown in FIG. 4, the wrench sockets 74 are disconnected from the sleeve nuts by pushing shafts 75 farther into tubes 76, and the clamping brackets 30 are unbolted from stanchion arms 28. Except for the sleeve assembly 67, which remains on the casing and may if necessary be welded in place, the shell can now be removed for re-use since the fluid flow can be controlled by the valve that was installed above the shell as previously described.

It is contemplated that the shell will be provided with a normally capped pipe fitting 80, FIG. 5, so that if desired, while the'shell is still mounted on the casing, fluid that fills the shell can be diverted to another conduit. In addition, the shell may be provided with fittings 81 for drainage or introducing blow-out air into the shell.

From the foregoing description it will be apparent that the invention provides a novel and very effective apparatus for blocking fluid flow in a well casing. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

I claim:

1. In an apparatus for blocking fluid flow in a well casing, a shell arranged to enclose a portion of the casing in a sealed manner, a carriage supported in the shell for movement towards and away from the casing, a saw blade mounted on the carriage for reciprocating movement relative thereto, the width of the saw blade being greater than the outside-diameter of the casing, means in the shell to reciprocate the saw blade, and means operable when the blade is reciprocating to move the carriage toward the casing whereby the blade cuts through the casing and, because of its width, blocks the flow of fluid therein.

2. Apparatus as defined in claim 1 wherein the shell comprises two mating parts one of which includes means for releasably mounting it on the casing, and releasable means to secure the parts together to enclose a portion of the casing after the one part has been mounted thereon.

3. Apparatus as defined in claim 1 wherein the means to reciprocate the saw blade is a motor, the apparatus including external means to start the motor and internal means to stop it after the saw blade has cut through ternal meanson the shell for moving the carriage away from the casing to wit draw the saw blade therefrom after the cutting operation.

6. Apparatus as defined in claim 5 together with a sleeve assembly releasably mounted on the casing above the plane of the saw blade, and means on the shell to enable the sleeve assembly to slide down on the casing and encircle the saw cut therein after the saw blade has been withdrawn from the casing.

7. An apparatus for blocking fluid flow in a well casing comprising a shell arranged to enclose a portion of the casing in a sealed manner, the shell having two hingedly connected mating parts to enable it to be mounted on the casing; a carriage supported on one part of the shell for movement towards and away from the casing; a metal cutting saw blade mounted on the carriage for reciprocating movement relative to the casing, the width of the saw blade being greater than the outside diameter of the casing and the plane of the blade being substantially perpendicular to the longitudinal axis of the casing; motor means in the shell to reciprocate the saw blade; means operated by the reciprocating movement of the blade to advance the carriage toward the casing whereby the blade cuts through it and, because of its width, blocks the flow of fluid therein upon completion of the cut; means forming a part of the carriage advancement means to move the carriage away from the casing and withdraw the saw blade therefrom after the cutting operation; a sleeve assembly in the shell encircling the casing, the assembly being releasably held on the casing above the plane of the saw blade during the cutting operation; and means on the shell to enable the sleeve assembly to slide down on the casing and encircle the saw cut after the saw blade has been withdrawn from the casing.

8. Apparatus as defined in claim 7 including means on the exterior of the shell to start the motor means, and means in the shell operable to stop the motor means after the saw blade has cut through the casing.

9. Apparatus as defined in claim 7 wherein the carriage advancing means includes a screw shaft extending from the exterior into the interior of the shell through a screw threaded fitting, a pinion on the inner end of the shaft adjacent the saw blade, a ratchet tooth on the blade engageable with the pinion during movement of the blade in one direction whereby the pinion is turned and the shaft moved longitudinally, and means connecting the shaft with the carriage so that it moves with the shaft.

10. Apparatus as defined in claim 9 wherein the means for moving the carriage away from the casing comprises a handwheel outside the shell on the outer end of the screw shaft.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 693 715 Dated September 26 Y 1972 John M. Brown Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 43, "20" should read 2 Column 6, line 19, next to the last Word, "on" should read Signed and sealed this 13th day of February 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 60376-P69 a u.s. GOVERNMENT PRINTING OFFICE: I969 o-ass-su,

Claims

1. In an apparatus for blocking fluid flow in a well casing, a shell arranged to enclose a portion of the casing in a sealed manner, a carriage supported in the shell for movement towards and away from the casing, a saw blade mounted on the carriage for reciprocating movement relative thereto, the width of the saw blade being greater than the outside diameter of the casing, means in the shell to reciprocate the saw blade, and means operable when the blade is reciprocating to move the carriage toward the casing whereby the blade cuts through the casing and, because of its width, blocks the flow of fluid therein.

3. Apparatus as defined in claim 1 wherein the means to reciprocate the saw blade is a motor, the apparatus including external means to start the motor and internal means to stop it after the saw blade has cut through the casing.

4. Apparatus as defined in claim 1 wherein the means for moving the carriage toward the casing is operated by the reciprocating movement of the saw blade.

5. Apparatus as defined in claim 1 together with external means on the shell for moving the carriage away from the casing to withdraw the saw blade therefrom after the cutting operation.