US3032110A - Downhole actuator for well tools - Google Patents

Description

May 1, 1962 V. D. HANES ETAL DOWNHOLE ACTUATOR FOR WELL TOOLS 2 Sheets-Sheet 2 Filed April 21, 1959 VAUGHAN DEAN HANES INVENTOR.

LOUIS ZERNOW ATTORNEY 3,632,110 Patented May 1, 1962 3,032,110 DOWNHOLE ACTUATOR FOR WELL TGOLS Vaughan Dean Hanes, West Covina, and Louis Zernow,

Glendora, Caiifi, assignors to Aerojet-General Corporation, Azusa, Calif, a corporation of Ohio Filed Apr. 21, 1959, Ser. No. 807,866 7 Claims. (Cl. 166-63) This invention relates to firing devices adapted to initiate operation of tools suspended by a line in a well and provided with self-contained operating means which require to be started by an external agency. The invention 1s specifically intended as a firing device for actuation of tools used in the oil well art.

Oil wells require that a variety of operations be carried out such as acidizing, casing perforation, sealing off, or cementing. in such operations, actuation of the tool has to be effective at a particular point in the well bore.

In most cases the firing device will be combined with a specialized tool, and since the particular construction of tool to be operated is immaterial to the invention, the following description will refer to the firing device only, of a propellant operated tool by way of example.

The lowering of a tool by a line into an oil well, particularly those wells of considerable age or depth which are the type most frequently requiring special work, is often not a straight-forward matter. Such wells may not be straight, well casings may have lengths which have bulged, there may be deposits on the inner surface of the casing, or other obstructions present that interfere with lowering of line carried tools.

It will be evident that it is an advantage to use a line suspended tool capable of being jerked upwardly repeatedly if necessary in order to ease :or work the tool past obstructions in the well.

It is also much cheaper to provide oil well tools with self-contained firing means actuated by a device that may be operated by the wellcrew using the ordinary well equipment such as a measuring line since it is expensive to employ a service company to furnish and operate the special electrical equipment required for electrically operated tools controlled from the surface.

In addition, even in wells that are clean and straight, there may be magnetic attraction between the wellcasing and the iron go-devil or cable that makes the use of a go-devil impractical, or there may be twists or kinks in the cable which prevent the free fall of the go-devil down the cable.

ger the firing mechanism of a tool of the type described by the use of a conventional go-devil, which is a weight that is designed to be dropped down the well guided by the tool suspending line to operate the trigger mechanism of the tool.

It is an object of the invention to provide a firing device for well tools suspended on a line so arranged that its operation is delayed until after one or more sharp upward movements of the device have been effected by the line on whichit is suspended.

It is another object to provide a firing device for oil Well tools of the kind described, which is operated by an upward pull on the tool provided that said upward movement is effected at a relatively rapid rate, whereas a slow raising of the suspending cable is effective to lift the device without causing its actuation.

It is a further object of the invention to provide a simple and inexpensive device which may be used in most cases with the usual measuring line and reel used in the oil well top of the case.

which will appear from the following description read with reference to the accompanying illustrative drawings, the invention provides a firing device for a suspended well tool provided with self-contained operating means and comprises a casing connected to the suspending line and containing firing means adapted to be operated by a member projecting slidably through the upper end of said case and engageable with a buoyant member freely slidable on the suspending means within a short distance of the The sliding movement of the buoyant member is limited by an abutment on the suspending line.

The buoyant member is constructed so that it rises in the well fluid more slowly than the casing can be raised by a quick upward pull on the suspending line thus enabling the device and tool to be withdrawn from the well without operating the firing mechanism in the casing, if necessary, by raising the line slowly. The device is preferably arranged so that it, and the suspended tool may be repeatedly jerked upward and again lowered a predetermined number of times without causing operation of the firing means, a rapid upward movement in excess of the predetermined number being effective, however, to cause operation of the device.

In the drawings:

FIG. 1 is an elevational view showing the firing device with an attached oil tool of the kind operated by gas generated by a charge of slow burning propellant contained in the tool, shown for example as a packer, being lowered into an oil well casing;

FIG. 2 is an elevational view of the parts shown in FIG. 1 but with the tool set in position and the firing device being removed from the well;

FIG. 3 shows the firing device in central longitudinal 7 section, but on a larger scale, in the position shown in FIG. 1; 1 FIG. 4 is a fragmentary detail view of parts shown in 5 FIG. 3 but showing them in operating position;

FIG. 5 is a fragmentary detail view showing the relal tive position of the operating member of the firing device and a buoyant member cooperating therewith while the firing device is being slowly raised out of the well;

FIG. 6 is a schematic wiring diagram showing electrical circuit of the firing device in initial position; and

FIG. 7 shows the electrical circuit in operating position. Referring now to FIGS. 1 and 2, a portion of an oil well is shown having a casing 1 containing liquid 11 and having a derrick mounted at the surface with a line 3 running over a sheave 4 and wound on a hoisting drum 5 driven by any suitable power means (not shown).

10 sliding freely on the rod 8.

The tool having self-contained operating means may be 'of any type provided only that the operating means of;

the tool require to be started into operation by an outside agency. An example of such a tool is disclosed in copending application Serial No. 673,339, filed July 22,

1957, and assigned to the sameassignee as in the present application.

The tool 6 may be attached to the firing device 2 by v a shearable pin 7, but the means by which the tool, or an instrument, such as a logging instrument may be connected to the device, may be of any suitable type and does not therefore form part of the invention.

Referring now to FIGS. 3 and 4 and going upward in the structure, the firing device 2 comprises a case closed at its lower end and including the adapter 18, a cylinder 19, a union or connecting and relatively thick member 20, and an open ended tubular guide member 21. The

cylinder 19 is secured to the upper end of the adapter 18 by a threaded joint 22, and to the member 20. by a threaded joint 23, while the tubular guide 21 is secured at its lower end to the member by the threaded joint 24.

The adapter 18 is longitudinally drilled to provide an axial passage as shown at 25 and member 20- is drilled axially as shown at 26, the axial bore being provided with a circumferential groove 27 in which is positioned an O, ring seal 28,.

The wall of tlhe tubular guide 21 is drilled transversely to its axis to provide diametrically opposite holes 253 and an attachment member in the form of a pin 30 is mounted extending across the bore 31 of the tubular guide 21 with its ends fitting in the holes 29. The bore 31 of the guide 21 is counterbored at 32. adjacent its lower end to facilitate machining. The lower end of rod 8 is screwed into pin 30 as indicated at 60 (FIG. 3) and the upper end of rod 8 is screwed into the cable head 9 as indicated at 61. The cable head 9 is provided with an eye 62 by which line 3 is secured to the head 9 as indicated at 63.

Electrically actuated firing means generally indicated at 16 (FIG. 3) are positioned within the cylinder 19 between union member 20 and the adapter 18. The electrical firing means 16 comprise switch tripping means generally indicated at 15, including an operating rod 33, a compression spring 34 coiled around, opera-ting rod 33 between the upper surface 36 of member 20 and lower end face 37 of the body of the switch nipping means 15, into which the rod 33 is screwed as indicated at 49. The spring 34 is of sufficient stiifnessto support the weight of the buoyant drag member 10 and head 35 without deflection. Body 35 is formed as a cylindrical member with a central bore 41 through which rod 8 extends, and a transverse elongated slot 42 through which pin 30 extends. Consequently body 35 is movable on rod 81 within limits defined by the upper and lower edges of elongate slot; 42.

Operating rod- 3.3 is: providedwith a collar 38 limiting its upward movement through member 20 and may project beyond the collar 38 as indicated, at 39.

The schematic circuit shown in FIG. 6 includes a normally'open single pole-single throw switch 43, and a battery. 44-, one terminal of which is connected by lead 48 to one terminal of the switch, the other terminal of the, switch being connected by lead 53 to ground, indicated at 56. The other terminal of the battery 44 is connected through lead 49 to one terminal of the solenoid 70 of a stepping switch 46, the other terminal ofthe solenoid being, connected by lead 54, to ground indicated at 57.

Stepping switch 46 is shown as provided with twelve contacts, only the last one 71, however, being connected to one terminal of battery 45. through lead 50. The arm 68 of the stepping switch 46 initially rests against one side of a stop 69 and when stepped around to the live contact 71, rests against the opposite face of stop 69. The arm 68 is connected through lead 55 toground indicated at 58.

The other terminal of battery is connected through lead 51 to the electrical igniter 47 for the gas producing material, which may be a charge of slow burning propellent (not shown), then through lead 52 to ground indicated at 59. The igniter 47 may be of any type but is indicated as a coil of resistance wire which it will be understood is surrounded by gun powder or other. pyrotechnic material, the ignition of which will ignite the associated charge of slow burning propellant.

In FIG. 7, the. switch 43 is shown as closed and the stepper switch arm as resting on the 12th contact, thus completing a circuit from battery 45 through the electrical igniting element 47. The; plurality of contacts enables thestepper switch to be set to the particular job, for instance, if the well has an unobstructed bore, battery. lead could be connected to thethird contact.

As shown in FIG. 3, the passage 25 is closed at its lower end around lead 51 against the entry of well fluid by any suitable seal 25a.

The buoyant member 10 is provided with an upper end 64 of considerably greater diameter than the lower end to serve as a drag, as described below. It further includes an axial bore 65, and with an axial recess 66 in its lower face. The recess 66 is adapted to loosely fit the head 35. With this arrangement, if the device is immersed in a liquid such as in an oil well shaft, and if line or cable 3 is raised, upwardly at a, high speed, or a jerking movement is applied to the line, the drag exerted on the buoyant drag member by the liquid in the case or oil, well shaft, will cause the buoyant drag member to move down the rod until the head 35 enters recess 66, trapping and compressing liquid therein. Consequently, the force exerted on the buoyant drag member by the liquid is transferred through the compressed liquid to the head 35, causing the head to move down the rod against the biasing force exerted by spring 39. This continues until the movement of head 35 down rod 8 forces operating rod 33 which is connected to head 35, against the opposed operating member of switch 43, thereby causing the switch to close. However, a long continued pull on the cable at a slow rate will prevent the operation of the initiating means while the device is being raised through well fluid. After leaving the fluid, however, the head 35, because of the weight of the buoyant member '10 will be finally fully seated in the recess 66, but without operating the firing means since the weight of the buoyant member 10 plus head 35 is insufificient to compress spring 34.

The buoyant member 10 may be formed in any suitable manner, as for instance from foamed plastic provided with an impervious skin of metal sheet welded or brazed into shape and, of sufficient strength to withstand the pressure in the well.

Operation The complete assembly of the. firing device and well tool is lowered to somewhat below the point at which the packer is to-v be. set. Assuming that an unobstructed length of well casing has been traversed and that the stepping switch 46 is designed to be stepped by impulses transmitted to it through closing of the normally open switch 43 eleven times before closing a circuit through the igniter 47, the line 3 would be jerked upwardly eleven times to effect ignition of the slow burning propellants and operation of the tool on the eleventh jerk.

If a well is being treated. which requires the firing device to be worked around partial obstructions by repeatedly jerking it upward, say seven times lowering it after each jerk, only four subsequent jerks on the cable 3 would be required, the firing device being actuated on the fourth and final jerk of the last series. If the firing device could not be lowered to the required depth even after ten upward jerks of the cable, the device could be raised out of the well without causing operation of the firing means byretracting it at such a rate that the buoyant member either floated ahead of the firing device, or the head 35 gradually entered the recess in the buoyant operator so that fluid therein was enabled to escape. When above the level of the liquid in the well, since no liquid would remain in the recess in the buoyant operating member, this recess being deep enough to contain the whole of the projecting portion of the head as shown in FIG. 5, raising could' be effected at maximum speed without danger of operating the device.

It is to be noted that while the invention has been described, as used to commence thev operation of a propellant actuated well tool, other types of well tools containing other means for operating the tool but requiring to be set into operation at a definite depth in the well may be actuated by-the firing device. of this invention.

There are a wide variety of such tools, such as well casing and formation perforating guns, tools containing a charge of compressed gas which is released from a container, or gas producing materials caused to react when well liquid is admitted to the interior of the tool, or containing motors run by batteries in the tool and operating timing devices for instruments, and numerous others. Some of such tools would remain attached to the firing device of the invention and be withdrawn from the well after their work had been done.

A preferred embodiment of the invention has been specifically described and shown in the drawings by way of illustration but not as limitative of the invention since various changes may be made therein by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

We claim:

1. An actuator for an oil well tool comprising: an elongated case having a longitudinal passageway therethrough, an upstanding rod fixedly attached to said case, a buoyant member having a recess therein and slidably mounted on the said upstanding rod, a head member received by the said case passageway and slidably mounted on the upstanding rod, said head member received by the buoyant member recess, a liquid-tight partition positioned within the case transversed to the case passageway defining a sealed liquid-free housing, resilient means interposed between the case partition and the head member, a downpending shaft fixedly attached to the head member, said shaft extending through the liquidtight partition, a switch attached to the case, said switch inside said sealed housing with an operating member opposed to and in spaced relationship to the downpending shaft, and a cable attached to the case so that if said actuator is immersed in a liquid and a jerking movement is applied to the cable, the drag on said buoyant member caused by the jerking movement of the cable will cause the buoyant member to move down the rod until the head member enters the said recess to compress the liquid in the recess in the buoyant member, whereby the force exerted on said buoyant member by the liquid due to the jerking movement of the cable will be transferred to the head member through the compressed liquid, causing the head to move down the rod against the biasing force exerted by said resilient means until the downpending shaft moves into engagement with the operating member of the switch to close it.

2. An actuator for an oil well tool as defined in claim 1 having a pin fixedly attached to the case and transversely positioned across the longitudinal axis of the longitudinal passageway of the case, said head member having a slot extending therethrough transversely positioned and elongated in the direction parallel to the case passageway, said pin extending through the head member slot thereby limiting the movement of the head member.

3. An actuator for an oil well tool as defined in claim 1 having an abutment attached to the rod positioned above the buoyant member and below the said cable thereby limiting the upward movement of the said buoyant member.

4. An actuator for a tool in an oil well comprising a case, a normally open switch fixedly attached to said case, said switch having an operating member, a pull rod connected to said case, a push member movably mounted on said pull rod for movement into engagement with said operating member to close the switch, means biasing said push member out of engagement with said operating member, a drag member movably mounted on said pull rod and in operative association with said push member so that if said actuator is immersed in a liquid and said pull rod and case are pulled through said liquid at a predetermined speed, the force exerted on said drag member by said liquid as it is pulled through said liquid moves said drag member on said pull rod into engagement with said push member, thereby causing a force to be exerted on said push member suflicient to overcome an opposing force on said push member exerted by said biasing means whereby said push member moves into engagement with said operating member to actuate said switch.

5. An actuator for an oil well tool comprising a case, an upstanding lift rod fixedly attached to said case, a buoyant drag member slidably mounted on said lift rod, said drag member having a recess with a base surface therein, a switch tripping means slidably mounted on said lift rod and positioned between said buoyant member and said case, said recess in said buoyant member shaped to receive the switch tripping means, a switch fixedly attached to said case, said switch having an operating member for engagement with said switch tripping means, resilient means positioned between the case and the switch tripping means biasing the switch tripping means out of engagement with said operating member, and a cable attached to the lift rod whereby if said actuator is immersed in a liquid and the lift rod is pulled up through the liquid at a predetermined speed by said cable, the force exerted on said buoyant drag member by said liquid causes the buoyant drag member to move down the lift rod until the switch tripping means enters said recess and compresses the liquid therein between the base of the recess and said switch tripping means, whereby the force exerted on said buoyant drag member by said liquid is transmitted through said compressed liquid to said switch tripping means, causing said switch tripping means to move down the rod overcoming the biasing force exerted by said resilient means until the switch tripping means moves into engagement with said operating member of said switch to close it.

6. An actuator for an oil well tool as defined in claim 5 having an abutment attached to the rod positioned above the buoyant drag member and below the cable thereby limiting upward movement of the buoyant drag member.

7. An actuator for an oil well tool as defined in claim 5 having a sequencing switch means attached to the casing and in electrical contact with the said switch means.

References Cited in the file of this patent UNITED STATES PATENTS 2,331,058 Stick Oct. 5, 1943 2,640,547 Baker June 2, 1953 2,870,841 Conrad et a1. Ian. 27, 1959 2,871,946 Bigelow Feb. 3, 1959

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