US3045081A - Initiating device for oil well tools - Google Patents

Description

July 17, 1962 v. D. HANES INITIATING DEVICE FOR OIL WELL TOOLS 2 Sheets-Sheet 1 Filed April 21, 1959 :9 INVENTOR. VAUGHAN DEAN HANES ATTORNEY July 17, 1962 v, HANES 3,045,081

INITIATING DEVICE FOR OIL WELL TOOLS Filed April 21, 1959 2 Sheets-Sheet 2 VAUGHAN DEAN HANES ATTORNEY United States Patent 3,045,081 INITIATING DEVICE FOR OIL WELL TOOLS Vaughan Dean Hanes, West Covina, Califi, assignor to Aerojet-General Corporation, Azusa, Califi, a corporation of Ohio Filed Apr. 21, 1959, Ser. No. 807,928 8 Claims. (Cl. 200-61.53)

This invention relates to devices adapted to initiate operation of tools suspended in a well and provided with self-contained operating means which require to be started by an external agency. The invention is specifically intendedfor initiating the operation of tools used in the oil well art.

Such wells require that a variety of operations be carried out such as acidizing, casing perforation, sealing 01f, or cementing. In such operations, actuation of the tool has to be effective at a particular point in the well bore, often at a depth of some thousands of feet.

In most cases the initiating 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 initiating device only, used with a propellant operated tool, by way of example.

The lowering of a tool 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 truly vertical, casings may have lengths which have bulged, or there may be deposits on the inner surface of the casing or other obstructions therein that interfere with lowering of cable carried tools.

It will exident that it is an advantage to use a wire line or cable suspended tool capable of being jerked upward repeatedly in order to ease or work the tool past obstructions in the well. I

In addition, even in wells that are clean and straight there may be magnetic attraction between the well casing and the iron go-devil or cable which makes the use of a go-devil impratical, or there may be twists or kinks in the line which prevent the downward free fall of the godevil.

For reasons above given, it is impracticable to trigger the firing or initiating 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 cable to operate trigger mechanism of the tool.

It is also much cheaper to provide oil well tools with self-contained firing means that may be operated by the well crew using the ordinary well equipment 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.

It is a particular object of the invention to provide an initiating device for tools operated by the pressure of gas generated by a charge of slow burning propellant or other source of potential energy, contained in the tool, the device being provided with means effective to initiate operation only after several sharp upward movements of the device have been effected by the cable on which it is suspended.

It is another object to provide an initiating 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 3,045,081 Patented July 17, 1962 oil well industry and can be operated by maintenance men or other semi-skilled workers, thus avoiding the cost of special equipment and skilled crews.

It may be mentioned that a measuring line is a light line carrying a weight and running over a reel of known circumference, such as three feet, furnished with a counter by which the length of line payed out is read. Such line and reel equipment is standard commercial equipment, the lines coming in various thicknesses according to the purpose for which it is to be used. A line .187" in diameter designed to carry loads in excess of 1250 lbs. is amply strong for use with the device of this invention.

Basically, the invention is a device to actuate a switch at a desired depth within an oil well. A fluid damped weight is contained in a liquid-filled housing and is connected to a jerking means. Upon a jerking movement, the weight is moved downwardly displacing liquid and acts upon a cup-shaped member which reacts downwardly thereby actuating a switch contact.

In the drawings:

FIG. 1 is a view in elevation showing the initiating device and well tool suspended therefrom being lowered into position in a Well.

FIG. 2 is a View similar to FIG. 1 showing the initiating device being raised after having caused operation of the well tool by a rapid upward pull on the cable.

FIG. 3 is a vertical central section through the initiating device in the position shown in FIG. 1 but drawn on a larger scale.

FIG. 4 is a view similar to FIG. 3 but showing the position of the parts at the instant of initiation of the operating means in the tool suspended from the device.

FIG. 5 is a schematic diagram of the electrical equipment and circuits incorporated in the device in the inoperative position.

FIG. 6 is a schematic diagram of the electrical equipment and circuits incorporated in the device in the operative position.

Referring now to FIG. 1, the numeral 1 indicates the well casing, the initiating device 2 with attached tool 3 being suspended therein by a line 4 which runs over a sheave 7 and is operated by a winding drum 6. In FIG. 2, the initiating device is shown as having been operated and separated from the tool 3 which is shown in set position in the well casing as indicated at 8, the numeral 9 indicating a gap showing that after firing no connection exists between the initiating device and the tool.

It is pointed out that the tool 3 is merely diagrammatically represented, the only requirement being that the tool should be provided with self-contained operating means which require to be initiated into action by an outside agency. An example of such a tool is disclosed in copending application Serial No. 673,339, filed July 22, I957, assigned to the same assignee as in the present application.

As shown in FIG. 3, the initiating device 2 comprises an outer casing generally indicated at 10 having its upper end closed by a head13 secured as indicated by threads 14 to the upper end of a short guide casing 15 screwed into the top of a cylinder 16, as indicated at 17.

An operating weight member generally indicated at 11 is mounted in the upper portion of the casing 10, and self-contained electrical apparatus generally indicated at 12 is contained in the lower portion of the casing. The components and circuit arrangement of the electrical apparatus which effects the transmission of current to initiate operation of the tool 3 are more fully shown in FIGS. 5 and 6 and are later described.

The lower end of the cylinder 16 is closed by a thick partition member 18 having an axial bore 29 and screwed to the cylinder as indicated at 19.

A case 2% is screwed as indicated at 21 to the partition member 18 and extends downwardly therefrom.

An end closure 22 is screwed to the lower end of the case 29 as indicated at 23, and is provided with a downwardly extending tubular extension, the bore 34 of which is closed by the liquid tight seal 34b.

It is to be understood that all components of the case are made up with washers or rings between the parts so as to exclude oil well fluid from the interior of the case.

The casing llil is attached to line 4- by a stub 24 on the top surface of closure 13. An eye 25 is provided in the stub through which the line 4 may be threaded and secured in any suitable manner.

The guide casing 15 is formed with a relatively thick base 26 provided with an aXial bore 27 and drain holes 2%, the purpose of which will be later explained.

Base 26 provides a transverse partition toward the upper end of cylinder 16.

Cylinder 16 is provided intermediate its length with an inwardly projecting peripheral flange 31, the inner surface of the cylinder above the flange being indicated at 3710, and below the flange at 31b.

The various elements of the self-contained electrical circuits may be secured in any suitable manner as by screws, to the walls 32, 33 of the case 20.

The inertia operated motor arrangement ll comprises a cylindrical elongated weight 36 having a vertical guiderod screwed into the top of the weight as indicated at 37 and slidable in the bore 27 in the bottom of the casing 15.

The weight 36 is mounted on a helical spring 42 supported on the upper surface 43 of inwardly projecting flange 3E. The lower portion of the weight is reduced in diameter as indicated at 38, the shoulder 41 thus formed providing a surface resting on the upper end of the spring 42.

A dashpot cylinder generally indicated at 4 is resiliently mounted below the weight 36, with the upper portion of the wall 39 of the cylinder surrounding the lower end of the reduced diameter portion 38 of the weight 36.

The cylinder 4i is guided for vertical movement by a vertical rod 44 screwed into the relatively thick bottom of the cylinder as indicated at 45 and working in the axial bore 29 in partition 18. An 0 ring packing 39 is positioned around the rod 44 to prevent leakage of fluid through the bore 29. The rod 44 is provided with .a head 46 limiting its upward movement in partition 13 and the cylinder is yieldably held in its upper position by a coil spring 47 mounted around the rod 44 between the bottom surface 49 of the cylinder 40 and upper surface 43 of the partition 18. The pin 44 by its head 46 serves as an operating means for the self-contained electrical initiation means as will later appear. When in its uppermost position 50 as shown in FIG. 3, head 46 is out of contact with the electrical means.

It will be noted that the sidewall 3? of cylinder 40 extends upwardly past the flange 31 in its upper position as shown in FEG. 3 but is still between the inner surface of the flange in the lowered position of the cylinder shown in FIG. 4, so that the flange 31 cannot cause interference with the upper edge of the cylinder wall 39. The reduced diameter portion 38 of the weight 36 projects into the upper end of the dashpot cylinder 40 in the raised position of the weight and projects still further into the cylinder 4% in the lowermost position of the weight as shown in FIG. The downward movement of the weight 36 is limited by head 51 of the weight guide rod 35 engaging against the upper surface of base 26 of guide casing 15.

The upper chamber above the partition 18 in the casing lti is filled with liquid, indicated at 52, to a level considerably above the upper edge of the wall 39- of the cylinder do to insure that the cylinder is always filled with fluid below the reduced diameter portion 38 of weight 36. The portion 33 of weight 36 is a loose fit in the cylinder 44 so that the cylinder acts as a dashpot to the motion of the weight but a definite downward force will be transmitted through the liquid against the bottom of the cylinder dd and cause downward movement of the pin 29 depending on the speed of movement of the weight 36. To further control or adjust the speed of flow of displaced liquid out of the cylinder 40, ports 53 may be provided in the wall of the cylinder adjacent the bottom thereof.

Guide rod 35 is a free fit in the bore 27 to ensure that no constraint is offered to free movement of the weight 36. Since in handling the device while outside the well, liquid will probably spill into the space above guide member base 26, the drain passages 28 are provided to ensure that the liquid will drain back into the casing 10 when the device is placed in a perpendicular position in the well.

The schematic circuit shown in FIG. 5 includes a normally open single pole single throw switch 54, operated by switch plunger 63a (shown in FIGS. 3 and 4), and a battery 55, one terminal of which is connected by lead 59 to one terminal of the switch, the other terminal of the switch being connected by lead 63 to ground. The other terminal of the battery is connected by lead to one terminal of the solenoid 56s of a stepping switch 56, the other terminal of the solenoid being connected by lead 64 to ground.

Stepping switch 56 is shown as provided with twelve contacts, only the last one 560, however, being connected to one terminal of a second battery 57 through lead 61. Stepping switch 56 is old in the art and is available from the Guardian Electric Company, Clare Relays, or the Automatic Electric Company. The arm 56a of the stepping switch 56 initially rests against one side of a stop 56s; and when stepped around to the live contact 56 rests against the opposite face of stop 56st. The arm 56a is connected through lead 65 to ground.

The other terminal of battery 57 is connected through lead 62 to the electrical igniter 58 positioned in the oil tool 3 for the gas producing material, which may be a charge of slow burning propellant (not shown), then through lead 66 to ground. The igniter 58 may be of any type but is indicated as a coil of resistance wire which will be heated to red heat or above when connected in circuit. It will be understood that the igniter is surrounded by gun powder or other pyrotechnic material, the ignition of which will ignite the charge of slow burning propellant as is common practice.

In FIG. 6 the switch 54 is shown as closed and the stepper switch arm 56a as resting on the 12th contact indicated at 560, thus completing a circuit from battery 57 through the electrical igniting element 58.

The arrangement of the reduced end 38 of the weight 3-6 loosely fitting in cylinder 40 which itself is a loose fit in the opening through the peripheral flange 31 and with liquid filling the lower portion of cylinder 16, affords both a dashpot and lost motion arrangement preventmg actuation of switch 54 by minor displacements of the weight 11.

Operation In operation the initiating device 2 and the tool 3 suspended therefrom are lowered by the suspending measuring line 4- to the desired depth as indicated in FIG. 1, the components of the device being in the positions shown in FIG. 3 and the electrical circuit elements in the position shown in FIG. 5.

A quick, short, upward pull on the line 4 will cause the outer case 10 to be moved upward rapidly and the inertia of the resiliently mounted weight 11 will cause the reduced portion 33 of the weight 11 to enter more deeply into the bore of cylinder 40, displacing liquid therefrom through ports 53 and surging between the walls of the cylinder and surface of the piston 40. The pressure applied to the liquid in the cylinder 40 by the weight 11 will cause the cylinder 39 to move downwardly, compressing spring 47 and causing guide pin 44 to close switch 54 which will result in moving the arm 56a of the stepper switch 56 forward one step. The number of times the device requires to be upwardly jerked before the initiating circuit arranged therein is energized will depend on the number of steps provided for, in the embodiment given by way of example the circuit would be completed on the eleventh sharp jerk when arm 56a will come to rest on live contact 56c. It is to be understood that each upward jerk of the line is followed by a lowering of the well tool to position.

If it is necessary to repeatedly jerk the device to clear obstacles in the well bore or work it around them, the number of such movements will obviously be subtracted from the total number of sharp, upward movements required to cause completion of the initiating circuit in the device. If it is desired for any reason to raise the device without operating it, a slow, upward pull is given by the line 4 which will result in the weight 11 being carried upward with the device without changing its position relative thereto.

In the type of well tool operated by slow burning propellant, the continued build-up of pressure after opera tion of the tool is utiized to shear the means 5 connecting the initiating device to the tool as shown in FIGS. 1 and 3.

It should be pointed out that tool contained operating means for oil well tools, which means require to be initiated into operation by an outside agency, may be of widely different types. For example, the initiating device may be used to fire a squib effecting release of chemicals into one another to generate the gas pressure operating the tool, or the firing of the squib may be eflective to disrupt a closure of a container and release a body of gas under high pressure in the container into the tool.

The tool need not necessarily be freed from the initiating device after opreation, as for instance, if a casing perforating gun is to be operated, in which case the gun would be raised with the device after firing.

It is to be understood that while the initiating device has been described with reference to a well tool, the device may be used to position and set into operation various instruments used for taking readings in wells, the term tool is therefore to be understood to include any instrumentalities used in Wells and provided with self-contained operating means requiring to be started or initiated into operation by a separate device with which the instrumentality is more or less closely associated, and which is provided with means for generating an electrical impulse transmitted to said instrumentality.

I claim:

1. A device for actuating a switch within a well comprising: a liquid-filled housing, means for displacing liquid in the housing, a resiliently biased means for containing liquid slidably disposed within said housing positioned adjacent to said liquid displacing means such that the liquid displacing means may displace liquid in the liquid containing means, a rod fixedly attached to said liquid containing means and extending externally through said liquid-filled housing, a switch means fixedly attached to said housing and in spaced relationship with said rod, and a means for operating said liquid displacing means whereby the liquid is displaced within the liquid contain ing means thereby tending to force the rod in contact with the said switch means.

2. A device for actuating a switch as defined in claim 1 and in addition: a resilient means supporting the liquid displacing means in an upward position.

3. A device for actuating a switch as defined in claim 1 in which the said liquid displacing means is a weight, and resilient means coupled with said weight to support it in an upward position.

4. A device for actuating a switch as defined in claim 1 in which the said liquid displacing means is a weight suspended in the said liquid-filled housing, a resilient means supporting the said weight, and a jerking means fixedly attached to said weight.

5. A device for actuating a switch within a well comprising: a liquid-filled housing, a weight received by the said housing, a partition across the interior of said housing, a bolt fixedly attached to the said weight extending through the said partition with its head portion in spaced relationship with the said partition, a resilient means supporting said weight and tending to hold the weight against the said partition, an open-top container slidably within said housing below and in spaced relationship with the said weight, said container being of such configuration to receive said weight, a resilient means supporting the said container, a switch fixedly attached to the exterior of said housing and having a contact, a rod fixedly attached to said container and in spaced relationship and axially aligned with the said switch contact, and a cable attached to the said housing whereby a jerking motion of the cable causes a resultant downward movement in the weight displacing the liquid within the open-top container thereby causing the rod to engage the switch contact.

6. A device for actuating a switch as defined in claim 5 and in addition: an inwardly extending peripheral flange attached to the interior of said housing and positioned in spaced relationship with the said container, and said resilient means supporting said weight in contact with said flange.

7. A device for actuating a switch as defined in claim 5 and in addition said container having a plurality of ports in its lower-most portion adjacent the said rod.

8. A device for actuating a switch within a well comprising: an upright closed substantially cylindrical casing having a first and a second end, liquid contained by said casing, a substantially cylindrical element in spaced relationship with the walls of said casing slidably suspended within said casing from the first end, a resilient means contacting said casing and said cylindrical element urging said cylindrical element against the first end of said cylindrical casing, a cup-shaped member having an open end surrounding the cylindrical element in spaced relationship with its sides and bottom with the closed end of the cupshaped member directed toward the second end of the said casing, resilient means contacting the casing second end and the said closed end of the cup-shaped member, means for slidably retaining the movement of the cupshaped member, a switch fixedly attached to the exterior of the second end of the casing and having a contact protruding therefrom, said slidable retaining means positioned to be in spaced relationship with the contact of said switch, and a jerking means coupled with the casing to cause the cylindrical element to be resiliently forced further within the cup-shaped member displacing the liquid therein causing the slidably retaining means into engagement with the contact of the switch.

References Cited in the file of this patent UNITED STATES PATENTS 450,626 Kerstein Apr. 21, 1891 2,577,210 Ruska Dec. 4, 1951 2,667,223 Farris Jan. 26, 1954 2,854,539 Ruppel Sept. 30, 1958 2,950,908 Rainsberger et al Aug. 30, 1960

Images