US3662827A

US3662827A - Well control means

Info

Publication number: US3662827A
Application number: US70625A
Authority: US
Inventors: August L Segelhorst
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-08-25
Filing date: 1970-08-25
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16

Abstract

A control device for mounting in a well tubing and serving in place of a short section thereof, embodying normally retracted, expansible seal means to close the annular space around the device inside the well casing and to close the passage through the device, together with its own supply of pressure fluid for expanding the seal means, and remote control means to operate and test the seal means.

Description

[451 May 16, 1972 United States Patent Segelhorst [54] WELL CONTROL MEANS [72] Inventor:

mm am m mw U HJT 1 6 9 1 4 6 4 8 7 2 3,367,422 2/1968 Sims.............. August L. Segelhorst, 211 Las Alturas, Santa Barbara, Calif. 93103 Aug. 25, 1970 [22] Filed:

Primary Examiner.lames A. Leppink Attorney-Wham & McManigal Appl. No.: 70,625

ABSTRACT A control device for mounting in a well tubing and sewing In place of a short section thereof, embodying normally retracted, expansible seal means to close the annular space 77 8 82 .5 HH46, 63 634 Jb3B W7 8 8 m2 "7 "6 m6 m mm L I new k UhF 1.1.1 2 8 555 [.11

f. n m o .w w e o lUO cmm w d m n5 ah.. 8 m m mm around the device inside the well casin mu passage through the device, to

pressure fluid for expanding th trol means to operate and test the seal means.

Warrington..........v.................

166/ 1 87 13 Claims, 7 Drawing Figures Il-IIIIIIM v 4 v \\s K s, a M Ma M a ,2 a 5 l M 5 M2 53 2E3 Q 3 5 3 a v WELL CONTROL MEANS This invention has to do generally with devices and means used to .control the escape of oil and gas under pressure from oil wells, and particularly to devices and means designed for use under emergency or unusual conditions when there has been a loss of control of the well by the conventional means used in day-to-day production of oil or gas. An example of loss of control is the blowout of casing head control devices due to excess pressure or accidentaldamage. Another example is the breaking of the casing and/or tubing below the surface of the ground, or below the surface of the water in wells drilled offshore, due to accidents, storms, earthquakes or other causes with the consequent escape of vast amounts of oil and gas presenting grave dangers on land and pollution of the water and shoreline where the well is located offshore.

It is a particular object of the invention to provide novel means for controlling a well by sealing off or closing the fluid passages at a desired region below the top of the well and to do this automatically in the case of serious damage to the well at a point thereabove.

Another object is to provide novel means for controlling a well which can be operated from a remote point for the purpose of testing the closure means or for the purpose of functionally closing the well for an extended period. In this connection it is an object to provide a system that will operate automatically to close or seal the well in the event of failure of the remote control means.

A further object and feature is to provide a well control system embodying a device or apparatus designed to be located in the well at a desired depth which contains its own supply of pressure fluid for actuating the means for sealing off or closing the fluid passages of the well.

In summary, it is an object to provide a novel control means for a well which includes a device adapted to be connected into the tubing of the well provided with a fluid-operable normally retracted expansible sealing means adapted to close the well tubing and the annular space between it and the casing against flow of pressure fluid from the well, the device having its own supply of pressure fluid to operate the seal means, and being controllable from a distance at a desired remote point by a system of valves and conduits connected between it and a source of fluid under pressure.

These and other objects will be apparent from the drawings and the following description. Referring to the drawings:

FIG. '1 is a fragmentary sectional view through a portion of a cased well showing the tubing therein and a well control device embodying the invention connected into the tubing as a section thereof;

FIG. 2 is a sectional elevational view through the well control device in the well, but on a larger scale;

FIG. 3 is a cross sectional view on line 3-3 of FIG. 2;

FIG. 4 is a longitudinal sectional view through the valve on line 44 of FIG. 3, but on a larger scale;

FIG. 5 is a view similar to FIG. 4, but showing the valve in a different position;

FIG. 6 is a fragmentary sectional view, similar to FIG. 2, but showing a modification; and

FIG. 7 is a fragmentary sectional view in the same plane as FIG. 6, but on a larger scale.

More particularly describing the invention, referring first to FIG. I, an offshore well 11 is shown extending into the earth 12 beneath a body of water 13. The well has an outer casing 14 extending above the surface of the water from a depth in the ground and inside this a casing 15 is shown lining the well hole, although it will be understood that normally in many wells, depending upon the depth, there may be several casings. The well 11 is assumed to be in production and thus has a well tubing 18 extending from the region of the oil sands (not shown) to a point above the casing head 19. The tubing would in turn be provided with a head, although none is shown.

The present invention includes a device 21 which is incorporated in the well tubing and is designed to function to seal off the well in the event of damage to the well at some point above it, or in response to controls located at a remote point.

The device includes a main body 23 fromwhich a tubular section 24 extends upwardly and is connected to the tubing 18 thereabove by a conventional tubing collar 25. The device is thus suspended on the string of tubing, and as will appear, forms a link or a section thereof.

The body 23 is cylindrical and has a radially reduced lower portion 26 that is externally threaded at 27 to mount an intermediate body section 28. The latter has a threaded bore 29 in an internal flange 30 and is threaded at 31 at its lower end. A lower section 32 is received in member 28 and has a depending, internally threadedportion 33 to receive and support the next section of the well tubing 18. The construction described provides a peripheral recess 35 and an internal or inner recess 36 in which packing rings or

seals

37 and 38 are positioned, respectively. The packing rings are made of a suitable resilient material such as synthetic rubber, plastic or the like. Ring 37 has an annular groove 40 in its inner surface while ring 38 has a peripheral groove 41.

The upper portion of the device 21 has an outer wall section 43 which extends upwardly from the main body section 23 and terminates in a domed upper end 43' through which the tubular section 24 passes. Wall 43, tubular section 24, and the main body 23 form an annular pressure chamber 44. A fluid passage 45 leads therefrom to a cylindrical bore 47 from which a passage 48 leads to the recesses 35 and 36 which contain the packing rings. As will later appear a main valve member 50 is nonnally held in a position such that fluid under pressure (preferably gas or air) cannot escape from the pressure chamber 44 to reach the packing rings and cause them to expand.

In order to provide a surface against which the lower or inner packing ring 38 can be forced into sealing engagement when pressure fluid is applied behind the packing ring, I provide a sleeve 52 within the bore 53 of the device. This sleeve is closed at its lower end and consequently well fluid must pass around the sleeve which is of smaller diameter than bore 53. The sleeve is slotted at its upper end portion to provide elongated fingers 54 having upwardly and outwardly extending ends 55 that seat in a groove 56 in a member 23. The sleeve is thus detachably mounted and can be removed to service the well and afterward replaced.

The valve 50 is elongated and extends from a cylindrical housing 58 through the pressure chamber 44 into bore 47 of the main body. Housing 58 is shown mounted on a bushing 59 that is mounted in a threaded opening 60 in a plug 61 which threads into a neck 62 formed on the pressure chamber wall 43. The valve comprises an elongated tubular member which includes a cylindrical lower section 65, an intermediate section 66, a reduced upper section 67 and a piston section 68. The lower section is received in the bore 47, and, when the valve is down as shown in FIG. 4, serves to close the passage from the interior of the pressure chamber to the packing rings. A coil spring 70 between bushing 59 and the piston section 68 serves to raise the valve to the position of FIG. 5 unless means is provided for holding the valve down. In order to maintain the valve in closed position as shown in FIG. 4, I provide a line or conduit 72 running to the surface which can be provided with a supply of pressure fluid sufficient to overcome the force of spring 70. It will be noted that when in this position, the valve being hollow provides a passage 73 therethrough from the passage 48 which leads from the two packing rings through branch passages 48' to bore 47, and then along the reduced section 74 of the valve and through port 75 to a second conduit or pipe 76 which also leads to the surface or the top of the well. Normally pipe 76 leads to atmosphere so that with the valve in the position shown in FIG. 4 the packing rings are vented to atmosphere.

Thus with the main valve held down and closed only by the pressure of fluid above the piston section 68, it will be apparent that in the event of an accident or storm, earthquake or other cause which would damage the well at some point above the device and interfere with the supply of pressure fluid through conduit 72, the valve would rise to the position of FIG. 5 and open the passage from the pressure chamber 44 to the two packing rings and thereby expand the rings and automatically effectively close or sea] the well.

The device 21 can also be operated by means of controls located at any desired location. A simple means is shown diagrammatically in FIG. 1 wherein the pressure line or conduit 72 which may lead from a source of compressed air or gas is shown provided with a gauge and a valve 81 between the gauge and the well and a valve 82 beyond the gauge. Conduit 76 has a single valve 83. A pipe 84, with a valve connects the two

conduits

72 and 76.

With the arrangement shown, the device 21 can be actuated at any time from the surface, either for testing purposes, or for the purpose of closing or sealing the well. This is done by closing valve 82 and opening valve 85,

valves

81 and 83 being normally open. This relieves the fluid pressure on the main valve 50 which then rises allowing pressure fluid from chamber 44 to reach and expand and effectively actuate the

packing rings

37 and 38. To restore the parts to their original positions, valve 85 is closed and valve 82 opened. This vents the pressure fluid from behind the packing rings and allows them to return to their normal retracted positions. It is also possible to recharge the pressure chamber at any time by closing valve 83, opening valve 85 and with valve 81 also open, introduce pressure fluid through line 76 to valve 50 from which it escapes into chamber 44 through a port 88 controlled by a check valve 89. A check valve 90 prevents flow of pressure fluid to the packing rings.

Referring now to FIGS. 6 and 7, I show another form of the invention comprising a device in a special casing section 96 which would be incorporated in the well casing at the desired depth in the well. The device includes a main body 98 having a tubular neck 99 which is internally threaded to receive the tubing 18. The body includes a cylindrical depending wall 100 with a thickened lower internally and externally threaded sec tion 101. An outer ring 102 having a plurality of pivoted dogs 103 urged outwardly by springs 104 for engagement with a shoulder 105 in casing section 96 is mounted on the outer side of section 101 and an adapter 106 is mounted inside it. The latter has an internally threaded section 107 into which the well tubing is threaded. The three

parts

98, 102 and 106 define a perhipheral groove 110 and an inner or internal groove 111 which accommodate packing rings 1 l2 and 113 of the type previously described, respectively. These have grooves 112' and 113 and openings 115 in wall 100 establish communication between them.

A sleeve 117 is received with clearance in the bore 118 through the device and has a flange 119 at its upper end to seat on a shoulder 120 in the body 98. Holes 121 provide for the passage of fluid past the flange.

In order to actuage or expand the two packing rings I provide an injector means 122 which includes a cylindrical housing 123 mounted in a threaded counterbore 124 in casing section 96 opposite the packing ring 117. A bore 125 leads through the casing. Inside the housing I provide a needle assembly which includes a piston 126 with a hollow sleeve 127 that slidably receives a needle 128 having guide vanes 129 and a flat head 130 which serves as a valve, being releaseably held by spring fingers 131 against the piston. The end of the housing defines a passage 133 and the housing provides another passage, designated 134, to the other end of the cylinder.

In the operation of the device of FIGS. 6 and 7, pressure applied to the end of the cylinder through passage 133 moves the needle forward through the packing ring 113 into wall 100. There the needle comes to rest while the piston continues forward unseating the head 130 of the needle to open a passage for pressure fluid through the assembly to the interior of the two packing rings. When desired the needle can be returned by admitting pressure fluid through passage 134 to the piston. The head of the needle contacts the abutment 136 to return it to original position.

It may be noted that in either form of the invention, with the inner sleeve removed, a string of sucker rods may extend through the device and that the inner packing ring will sealingly engage the sucker rod in place of the sleeve which has been removed. In some cases, depending upon the diameter inside the body of the device, it may be necessary to incorporate a special enlarged section in the sucker rod string where it is received in the device to insure against there being too much clearance to enable the inner packing ring to effectively sealingly engage the rod. Such enlarged section would necessarily be made longer than the stroke of the pumping jack.

Also, it is advantageous to incorporate means for giving an audible signal of the escape of any consequential volume of air through the vent tube 76 to give warning of a failure somewhere in the system and to assist an operator in testing the device. Such means may be in the form of a whistle, designated 140 and shown diagrammatically in FIG. 1. The pressure gauge 80 serves to give warning of loss of pressure in line 22 when

valves

82 and 85 are closed.

Iclaim:

1. In apparatus for controlling an operating well having a casing and a tubing, a device connected in the tubing and having a well fluid passage therethrough from end to end, normally contracted expansible packing ring means carried by said device and expansible in response to the application of fluid pressure thereto whereby efiectively to close the passage through the device and to close the annular space between the device and the casing, said device having wall means forming a closed pressure chamber and providing a pressure fluid passage from said chamber to said packing ring means, a valve closing said pressure fluid passage, and control means for holding said valve in a normally closed position, said control means being subject to failure in the event of damage to the well at a point above the device so as to allow said valve to open.

2. The apparatus set forth in claim 1 in which means is provided for controlling said valve from a distance.

3. In apparatus for controlling a well having a casing and a tubing extending into the bore hole of the well, a body connected in the tubing and being of lesser outer diameter than the inner diameter of the casing thereby leaving an annular passage between the body and the casing, said body having a central passage therethrough in open communication with the tubing above and below the body, a sleeve member within and extending at least partially through said central passage and cooperating with said body to form an annular passage for flow of well fluid, said sleeve member otherwise restricting the passage, fluid-operable, normally retracted expansible packing ring means between said body and said casing and between said body and said sleeve member within the central passage thereof, said body providing a pressure chamber adapted to hold a supply of fluid under pressure, said body having fluid passage means between said chamber and said packing ring means, valve means controlling said fluid passage means, means for releasably holding said valve in a position such as to prevent flow of fluid from said pressure chamber and to vent fluid from said packing ring means to atmosphere, said valve means being operable to connect said pressure chamber to said packing ring means whereby to expand the same into effective sealing engagement with said casing and said sleeve member.

4. The apparatus set forth in claim 3 in which an auxiliary valve and fluid conduit means adapted to lead from a remote source of pressure fluid is provided for repressurizing said chamber.

5. In apparatus for controlling a well having a casing and a tubing, a device connected in the tubing and having a well fluid passage therethrough from end to end, normally contracted expansible packing ring means carried by said device and expansible in response to the application of fluid pressure thereto whereby effectively to close the passage through the device and to close the annular space between the device and the casing, said device having wall means forming a closed pressure chamber and providing a pressure fluid passage from said chamber to said packing ring means, a main valve in said device controlling said pressure fluid passage, means yieldably urging said valve to open position, and means for closing said valve and releasably holding it closed comprising a piston-like member in a cylinder attached to the valve and a conduit leading therefrom to a point outside the well and adapted to be connected to an external source of pressure fluid.

6. The apparatus set forth in claim 5 in which said device is provided with a vent conduit leading from said valve to a point outside the well, and in which said valve connects the passage to said packing rings to said vent conduit when said valve is closed.

7. In a device for controlling a well and adapted to be mounted as a link in the well tubing, said device having a body providing inner and outer expansible packing rings for closing the well when actuated by pressure fluid behind them, and having a pressure fluid storage chamber with a passage leading from said chamber to said packing rings, means for controlling said device, comprising a main valve controlling said passage, spring means yieldably urging said valve to open position, said valve having a piston portion received in a cylinder, a supply conduit leading from said cylinder to a point outside the well and adapted to be connected to an external source of pressure fluid, said piston portion of said valve being urged to overcome the force of said spring means by the presence of pressure fluid supplied through said conduit, a vent conduit leading from said valve to a point outside the well, said valve serving to establish communication between said vent conduit and the portion of said passage leading from said valve to the packing rings.

8. The device set forth in claim 7 in which said main valve includes an internal passage which serves as the means of establishing communication between the vent conduit and the portion of the passage leading from the valve to the packing rings, and in which said main valve is provided with a check valve-controlled port from the internal passage thereof to the interior of said pressure fluid storage chamber and with a check valve in said internal passage between said port and said portion of the passage leading to said packing rings.

9. The device set forth in claim 8 in which said vent and supply conduits are interconnected beyond the well by a valved pipe and in which said vent conduit is provided with a valve beyond said pipe and in which said supply conduit is provided with a valve on each side of said pipe.

10. The device set forth in claim'8 in which said vent and supply conduits are interconnected beyond the well by a valved pipe, in which said vent conduit is provided with a valve beyond said pipe and with means for giving an audible indication of the passage of gas therethrough in quantity, and in which said supply conduit is provided with a valve on each side of said pipe and with a pressure indicating means between the well and the valve farthest therefrom.

11. In apparatus for controlling a well having a casing and a tubing, a device connected in the tubing and having a well fluid passage therethrough from end to end, normally contracted expansible packing ring means carried by said device and expansible in response to the application of fluid pressure thereto whereby effectively to close the passage through the device and to close the annular space between the device and the casing, said device having wall means forming a closed pressure chamber and providing a pressure fluid passage from said chamber to said packing ring means, a valve closing said pressure fluid passage, and means for controlling said valve from a distance comprising a conduit adapted to lead from a source of pressure to said valve and to which said valve is responsive by being held in a given position when subjected thereto, and auxiliary valve means controlling said conduit.

12. In apparatus for controlling a well having a casing and a tubing, a device connected in the tubing and having a well fluid passage therethrough from end to end, normally contracted expansible packing ring means carried by said device and expansible in response to the application of fluid pressure thereto whereb effectively to close the passage through the device and to c ose the annular space between the device and the casing, said device having wall means forming a closed pressure chamber and providing a pressure fluid passage from said chamber to said packing ring means, a valve closing said pressure fluid passage, and means for releasably holding said valve in a position such that said fluid passage is closed, said latter means extending from the device in the well to the top of the well and being subject to failure in the event of substantial damage to a portion of the well above the device.

13. In apparatus for controlling a well having a casing and a tubing, a device for effectively closing the annular space between the casing and the tubing and for closing the tubing at a given region below the top of the well, comprising a body connected into the well tubing and in effect forming a section thereof at said given region, said body having a central passage therethrough in continuation of the passage through the interior of the tubing, an external packing ring carried by said body, an internal packing ring carried by said body, said rings being normally retracted, said rings being expansible in response to the application of fluid pressure behind the same whereby to become effective to close the annular space between the body and the casing and to close the passage through the device, and means to supply a pressure fluid to said packing rings, said means comprising a piston-like needle assembly mounted on a special casing section opposite said external packing operable under the influence of applied fluid pressure to penetrate said external ring and convey pressure fluid behind the same, said needle assembly being adapted to be connected to a source of pressure fluid.

Claims

1. In apparatus for controlling an operating well having a casing and a tubing, a device connected in the tubing and having a well fluid passage therethrough from end to end, normally contracted expansible packing ring means carried by said device and expansible in response to the application of fluid pressure thereto whereby effectively to close the passage through the device and to close the annular space between the device and the casing, said device having wall means forming a closed pressure chamber and providing a pressure fluid passage from said chamber to said packing ring means, a valve closing said pressure fluid passage, and control means for holding said valve in a normally closed position, said control means being subject to failure in the event of damage to the well at a point above the device so as to allow said valve to open.

10. The device set forth in claim 8 in which said vent and supply conduits are interconnected beyond the well by a valved pipe, in which said vent conduit is provided with a valve beyond said pipe and with means for giving an audible indication of the passage of gas therethrough in quantity, and in which said supply conduit is provided with a valve on each side of said pipe and with a pressure indicating means between the well and the valve farthest therefrom.

12. In apparatus for controlling a well having a casing and a tubing, a device connected in the tubing and having a well fluid passage therethrough from end to end, normally contracted expansible packing ring means carried by said device and expansible in response to the application of fluid pressure thereto whereby effectively to close the passage through the device and to close the annular space between the device and the casing, said device having wall means forming a closed pressure chamber and providing a pressure fluid passage from said chamber to said packing ring means, a valve closing said pressure fluid passage, and means for releasably holding said valve in a position such that said fluid passage is closed, said latter means extending from the device in the well to the top of the well and being subject to failure in the event of substantial damage to a portion of the well above the device.