US3105551A

US3105551A - Switch influencing devices

Info

Publication number: US3105551A
Application number: US87345A
Authority: US
Inventors: Harry C Ehlert
Original assignee: Camco Inc
Current assignee: Camco Inc
Priority date: 1961-02-06
Filing date: 1961-02-06
Publication date: 1963-10-01
Anticipated expiration: 1980-10-01

Description

Oct. l, 1963 H. c. EHLERT SWITCH INFLUENCING DEVICES 2 Sheets-Sheet 1 Filed Feb. 6. 1961 Oct. l, 1963 H. c. EHLERT 3,105,551

SWITCH INFLUENCING DEVICES Filed Feb. 6, 1961 2 sheets-sheet 2 C`. r/er INVENTOR "'\26 BY QC United States Patent O 3,105,551 SWITCH INFLUENCING DEVICES Harry C. Ehlert, Houston, Tex., assigner to Camco, Incorporated, Houston, Tex., a corporation of Texas Filed Feb. 6, 1961, Ser. No. 87,345 7 Claims. (Cl. 16o-65) This invention rela-tes to well working tools which can be suspended by wire line equipment for travel within a tubing string and signaled into operation iat a desi-red subsurface level.

An object of the invention is to provide -a simpliiied control for completion of an electric circuit and performance of an operation at a selected depth location within a well hole.

A further object is to provide a tool having self contained well working components including an initially open control switch which cl-oses with movement of a magnetically influenced device, together with ka oor-operating element shiftably carried by the tool for movement between a i-rst position in which the element acts as a barrier against switch closing magnetic effect and a second position in which the lbarrier is ineiiective against switch closing effect.

Another object of the invention is to provide a shiftably movable barrier element of the tool for tubing string 'bearing engagement whereby reversal of tool travel direc- `tion is operative for shifting the element from its initial position maintaining switch open relation to a position out of control of switch operation.

Other `objects will become apparent as the specication proceeds and with reference to the accompanying drawings wherein FIG. l is a vertical section of a fragment of a well tubing string and of a work performing tool whose working circuit is normally opened during tool descent; FIG. 2 is a diagram of a simplified circuit to be controlled by the Vdevice of FIG. l; FIG. 3 is a fragmentary elevation of a modiiied form of tool contained within a tubing string provided with a signaling station to trigger tool actuation; FIGS. 4 and 5 are elevations partly in vertical section schematically showing the (1o-operation of the tool and the tubing string during tool descent, and elevation respectively, and FIG. 6 shows a tubing string `and signaling station in section land a fragment of a tool body similar to lFIG. 3 but slightly modied.

The structure to be here disclosed for running into and -out of a wel-l tubing string is to signal the closing of an electric circuit control; the start of an operation either directly or through the release of ya source of energy, for performing various jobs Within a well hole, including the discharge of an inhibitor fluid; the setting of different types of downhole equipment, as well as the operation of a traveling recording instrument which is to be inactive during a vlower-ing operation and is to be placed in continuing action throughout a given range of return trip travel.

VIn FIG. l, a small portion of a tubular tool body 1 is shown with relatively movable parts in their positions assumed during down travel within a well tubing string 2. A reduced diameter nonmagnetic wall portion 3 of the tool affords an annular peripheral lgroove having at oppositely vertically spaced apart ends a downwardly facing stop shoulder 4 and an upwardly facing lower stop 3', i @555i Patented Oct. 1, 1953 shoulder 5 and slidably sleeved on the reduced diameter portion 3 is a collar or band 6 of `an axial length somewhat less than half the space between the

stop shoulders

4 and 5. The slidable sleeve or collar 6 thus has a range of movement between Ian upper position shown in iull lines, in which its upper end face abuts the upper limit stop 4, and a lower position shown by dotted lines, in which its lower end face abuts the lower limit stop 5. Maintenance of the respective positions and collar travel from one to the other thereof are by means of several radially expansible and resilient tubing string engageable friction bearing shoes or elements 7 conveniently in the form of outwardly bowed spring strips carried by and projected peripherally from the collar 6. During tool descent, the bow springs 7 frictionally bear or rub on the interior surface of the tubing string 2 and thereby retard or hold the slide collar 6 against dropping from its upper full line position. Upon reversal of tool travel direction, the frictional contact between the bow spring 7 and the wall of the tubing 'brakes or resists the rise of the shiftable collar 6 and the tool body 1 moves upward relative to the frictionally heid collar 6 until the collar stop shoulder 5 abuts the bottom end face of the repositioned collar.

Within the upper half of the reduced diameter tool section 3 or that region which is embraced within and surrounded fby the slide collar 6 when located in its uppermost position, there 4are mounted rinside the hollow tool body a pair of pole pieces or rings 8-8 spaced apart longitudinally and in transverse planes which intersect the raised collar near its opposite ends. In the space between the pole piece-s 8, ya rock lever 9 is fulcrumed centrally of its oppositely extending arms on a transverse mounting pivot illustrated as located slightly above a midpoint between the two pole pieces. This lever is magnetized or consists of a permanent bar magnet and its upper face near its south pole end is engageable with a stop lll located to limit .swing movement of the lever, as viewed in FIG. l, in a counterclockwise direction of rotation beyond the point which would place the rocker magnet north pole closer to the lowermost one of the two pole pieces S. Consequently, magnetic lines of force 'between the north land south Ipoles of the magnetized rock lever 9 normally tend to impel the north pole end to swing clockwise toward the upper pole piece 8 in the absence of an opposing or repelling force. A repelling force can be provided when the slide collar 6 i-s in its uppermost position around the pole pieces `by prem-agnetizing the collar itself or by incorporating in the collar one or more permanent magnet strips of a length to Ibridge the space between the pole pieces and by arranging the north pole at the upper end as indicated Iby the legend N and its sourth pole at the lower end indicated by the legend S. With the pole pieces 8 3 within the field of the magnetic collar 6, the field of the collar overcomes the influence of the field of the magnetized rock lever 9 by reason of the diiierence in polarity to deflect the poles of the rock lever in a counterclo'ckwise direction bringing the rock lever north pole downwardly `and the south pole into stop engagement with the limit abutment 16; In this action, the rock lever 9 serves as an armature between the opposite poles of the collar 6.

The relative swing positions o-f the rock lever 9 are here employed for affording an off and on switch in a work performing control circuit including one current lead wire connected Vto the rock lever and another lead wire connected to a contact 11 located in the path of a co-operating contact 12 carried by and formed as a part of the upper side at the north pole end of rock lever.

FIG. 2 is a simple Wiring diagram showing a part 13 to be signaled into action by current supplied from a. battery 14 Iwhen an arming or safety switch 1S has been preset in closed position at the start of a tool lowering operation and when the normally open switch afforded by the rock lever 9 is` freedV from the hold-open influence of the slide'collar magnet 6. ,So long as tool descent continues, the rub springs 7, due to their frictional bearing `co-operation with the tubing string 2, will maintain the collar dat its upper limit and bar closing of the rocker switch. At the time the descending tool reaches any preselected depth at which the well working operation is to be initiated, the direction of tool travel can be reversed and tool elevation, in `coi-operating with the tubing string and rub springs 7, results in a relative shift of the tool an-d collar from the upper ful-l' line position K to the dottedline position of FIG. 1 and removes the collar magnetic field from its influence upon the mag- Vnetilzed rock lever 9, which responds by swinging to the switch closing position for completing the electrical circuit to the part 13.

The embodiment illustrated in FIGS. 3, 4 and 5 enables a signaled performance of work Iat any one of several given depth locations as markedby signaling sta` tionsk incorporated in a tubing string for inuencing the response of circuit closing component-s of a well tool. An effective 4signal carried by a well tubing string 16 comprises an inwardly protruding magnetic field or fields provided, ilor example, by a set of two/longitudinallyspaced apart magnets 17 having radially inwardly and outwardly disposed ends of opposite polarity and being arranged with the inner face of the upper magnet as its south pole and the inward face of the companionlower magnet as its north pole for a strong tiux path or signaling field to- Y ward the center of the tubing string and between these inwardly lfacing magnet ends of opposite polarity. VThe magnets 17 may be in the form of rings or of annular rows of short length bar magnets in circularly'spaced apart succession and lare mounted or embedded in a tubing string annular insert 18 of nonmagnetic material.

The tool body 19 in this instance includes -a switch element `comprising a magnetized rock lever 20 similar to the element 9 previously described except that the pivot mounting and limit stops to rocking or teetering movement maintain the north pole of the rock lever 20' closer to the lowermost of 4a pair of pole pieces or rings -21-21,

whereby the field of magnetized rock lever 20 imparts a counterclockwise tendencyy for a normally .open circuit relationship. v Such normally open force is to be overcome when the'pole pieces 21 are within signaling fields of4 tube carried magnets such as those shown at 17. To screen the rock lever 2li `and its cfa-operating pole pieces 21 from and `as a ybarrier against counteracting magnetic fields until an operational response is desired, a slide collar 22 of magnetic material is slidably itted to a reduced diameter nonmagnetic tool body portion 23 whose top and bottom shoulders lim-it the Irange lof relative yslide travel, with the upper limit arranged to ,position the collar 22 `as a m-agnetic shield around the rock lever 20.v To maintain that position during tool descent within Vthe tubing string 16, the collar V22. is provided with rub springs 24 for frictional braking engagementA with the tub-ing string. To supplement such action and as a-sa'fety precaution against unintentional downward dieplacement of the collar 22, there may be empolyed a coil spring 25 sleeved on the reduced diameter tool body portion y2li for.

biasing the collar 22 in the upward direction.

During a tool lowering operation, the collar 22 of magnetic material will Vprevent response to any magnetic field traversed but following such traverse, a reversal .of

tool direction enables the rub springs 24, in cooperation with the tubing string 16, to check or resist collar elevation and the assumption by the collar of a position somewhat as illustrated by `broken lines in FG. 3, so that its shielding actionis rendered ineffective and the switching unit is uncovered or exposed to 'the switch closing influence of the'mugnetic signaling field next encountered in `continued upward tool travel. k

The switching arrangement just described is well adapted for combination and series circuit connection with an additional and identical switch unit including a magnetized rock lever 20a for responsive actuation upon traverse of a magnetic rsignaling field of a second set of tubing carried magnets 17a- 17a embedded either in the same insert member 18 vor one similar thereto. This second and normally open switch unit 20a is shown in FIG.

with one of several signaling stations embodied inthe tubing string 16 at each of several depth levels and arranged with the longitudinal spacing between the two sets of magnets 17and 17a of dimensions differing one Vfrom another. Selective adjustment of the spacings between the series connected switch units to match the spacing of signaling fields `at any given station, codes the tool forl response only to that station. When the .selected station is passed by the descending tool, the tool can then be raised whereby the shielding collar 22, in response to reverse upward travel, will be shifted to its ineffective position and no longer will serve as a barrier to the responsive action of the switch unit afforded by the rock lever 20. ThereafterV simultaneous closure of both switching units will complete the work performing control circuit as both units come simultaneously within' the magnetic fields ofthe two sets of tubing vstring carried magnets at the selected station.

Spaced apart stations with differently spaced apart signaling fields are shown in FIGS. 4 and 5, together with a work performing tool having a pair of series connected switches coded to match the signaling station of FIG. 5. For illustrative purposes, the lower portion of the tool is here shown as containing an inhibitor'liquid to be ejected upon signal closure of a circuit, which ignites an explosiverchargefor generation of pressure to blow out a liquid confining stopper 26. and discharge the inhibitor liquid.- Such circuit will remain open during lowering of the tool, as in FIG. 4, with the/shiftable collar 22 in its Veffective position barring one of the series connected switch units from response to all signal stations traversed. Tool manipulation, as previously mentioned, has occurred to expose both switch units simultaneously to the influence of magnetic fields and circuit completion has been effected in the FIG. 5 relation of parts. e

The arrangement in FIG. 6 parallels that of FIG. 3 except that the slide collar 122 is magnetized and its opposite endsof opposite polarity are arranged as in FIG. l

` to oppose and maintain the magnetized lever of the unit in circuit opening relation when the slide collar 122 1s at lts uppermost limit. The tool also includes an upper magnetic switch unit 120a and two sets of magnets 117 economy of manufacture, the movable collar in the multiple-switch arrangements disclosed controls only one -of the switch units. Should there ever be any occasion for shielding more than one switch unit, this could effectively be done by merely elongating the collar to serve both units or by providing separate collars, one for each switch unit.

Various modifications of the structural components specifically described can be made without departing from the invention as set forth in the accompanying claims.

What is claimed is:

l. In a well working tool adapted to be lowered in a tubing string and to co-operate therewith for the performance of work upon tool elevation, said tool comprising a body having suspension connection means for tool movement manipulation within a tubing string, electrically controlled work performing means carried by the body, a magnetically actuated switch therefor positioned in one region of a given portion of the body, a slide collar capable of acting as a barrier against switch actuation, said collar being shiftably mounted on said body portion for movement between a first position in which the collar is in radially surrounding relation with the region of the switch and acts as a barrier to switch actuation, and a second position in which the collar is outside said region and is ineffective as a barrier to switch actuation, collar stop abutments on the body establishing said positions between which the slide collar is shiftable, and tubing string engageable means carried by the collar for co-operation with the tubing string to maintain the collar in stopped relation with one of said abutments and in the first mentioned position during tool movement in one direction and to shift the collar to its other position and toward stopped relation with the other abutment in response to tool movement in the other direction.

2. In a well working tool adapted to be lowered in a tubing string and to co-operate therewith for the performance of work upon tool elevation, said tool comprising a body having suspension connection means for tool movement manipulation within a tubing string, a magnetic field influencing collar slidably sleeved on a portion of the body, a resiliently expansible element carried by the collar for frictional engagement with the tubing string to control collar position incident to relative tool movement, upper and lower stop surfaces at opposite limits of said body portion engageable alternately by the collar, said stop surfaces defining a first collar position and a second collar position, electrically controlled working mechanism carried by the body-and a switch therefor including a permanent magnet movably mounted on the body and whose magnetic field is influenced by the collar and controls magnet movement to switch open and closed relations, said movable magnet being surrounded by and under switch open maintaining influence of the field infiuencing collar in said first collar position and being out of collar influence in said second collar position.

3. In a well working tool for travel within a tubing string, a tool body having suspension connection means for tool movement manipulation within a tubing string, electrically controlled work performing means carried by the body, a control switch therefor including `a permanently magnetized element movable between a switch contact opening position and a switch contact closing position, pole piece means fixedly carried by the body within the field of said movable element for the magnetic attraction of the element to one of its positions, a second magnet slidably mounted on the tool body for movement into and out of flux linking relation with said pole piece means, said second magnet having its poles arranged to repel said magnetized element from said one of its positions when the second magnet is in said flux linking relation, and tubing string engageable means on the second magnet to effect sliding of the second magnet out of said flux linking relation incident to reversal of direction of tool travel within a tubing string.

4. In a well working tool for travel within a tubing string, a tool body having suspension connection means for tool movement manipulation within a tubing string, a control switch carried by the body and comprised of a pair of spaced apart pole pieces, a magnet fulcrumed between the pole pieces for co-operation therewith in normally biasing the fulcrumed magnet in one direction, another magnet slidably mounted on the tool body for movement between a first position in which the field between its poles includes said pole pieces and counteracts the force of the fulcrumed magnet to bias the fulcrumed magnet in the opposite direction, and a second position in which the field of the slidable magnet is ineffective through said pole pieces, means on the body establishing opposite limits of slidable magnet movement and maintaining the slidable magnet in either of said positions respectively, means carried by the slidable magnet for frictional slide bearing on the tubing string during tool travel to thereby control the position of the slidable magnet and a pair of circuit contacts one of which is movable with the fulcrumed magnet into closing relation with the other contact incident to movement of the fulcrumed magnet to one of said positions.

5. In a well working tool for travel within a tubing string, a tool body having suspension connection means for tool movement manipulation within a tubing string, a control switch carried by the body and comprised of a magnetized lever pivotally mounted centrally thereof in the body with opposite lever arms afforded north and south poles, a pair of pole pieces spaced apart on opposite sides of the lever for co-operation with its magnetic field in effecting a bias of the north lever arm toward one of the pole pieces, a contact in the path of one of the lever arms as a stop to lever travel under said bias and to complete a circuit on lever engagement with the contact, a magnet collar slidably embracing and being movable on said tool body to and from a position in which its eld includes said pole pieces, said collar in said position having its north pole nearer the pole piece to which the north pole of the lever is normally biased, a stop abutment on the body engageable by said collar to establish the collar position aforesaid, and tubing string engageable means carried by the collar and responsive to tool travel in the tubing string for controlling collar slide movement, said tubing string engageable means being active to effect collar movement to said position in response to tool travel in one direction and from said position in response to tool travel in the opposite direction.

6. ln a well working tool for travel within a tubing string having means providing a series of sets of inwardly protruding magnetic fields differently spaced apart in each set, said tool comprising a body having suspension connection means for tool movement manipulation within a tubing string, a set of spaced apart field influenced circuit closing devices arranged for coaction selectively with one of said fields on traversing the same, a collar of magnetic material slidably mounted on the tool body for movement to and from a position surrounding at least one of said circuit closing devices as a barrier against the imposition thereon of said fields, a collar stop abutment carried by the body and defining said position of the co1- lar, and tubing string engageable friction bearing means carried by the collar for controlling collar movement to said position in response to tool travel in one direction and from said position in response to tool travel in the opposite direction.

7. In a well working tool for travel within a tubing string having a magnetic eld signaling station at a subsurface depth, said tool including a body having suspension connection means for tool movement manipulation within a tubing string, a field responsive circuit closing device carried by the body and infiuenced upon traverse of a tubing string magnetic field, a shielding collar slidably mounted between a first position surrounding and rendering said device unresponsive and a second position Y 7 in which the shielding collar is ineffective, collar positioning stop abutments located by the body to define said positions of the slidable collar, and tubing string engageable bearing means carried by and maintaining the collar in said first position during tool descent Within the tubing string and shifting the shielding collar to said second' position upon tool elevation.

2,544,979 Brokaw et al Mar. 31, 1951 Ring June 28, 1955 Bendar Oct. 4, 1955 Ring ,July 22, 1958 Waugh June 20, 1961 '4 Feeser Apr. 3, 1962 Rumble May 1, 1962 i FoREiGN PATENTS Germany May 21, 1959 France June 13, 1960

Claims

3. IN A WELL WORKING TOOL FOR TRAVEL WITHIN A TUBING STRING, A TOOL BODY HAVING SUSPENSION CONNECTION MEANS FOR TOOL MOVEMENT MANIPULATION WITHIN A TUBING STRING, ELECTRICALLY CONTROLLED WORK PERFORMING MEANS CARRIED BY THE BODY, A CONTROL SWITCH THEREFOR INCLUDING A PERMANENTLY MAGNETIZED ELEMENT MOVABLE BETWEEN A SWITCH CONTACT OPENING POSITION AND A SWITCH CONTACT CLOSING POSITION, POLE PIECE MEANS FIXEDLY CARRIED BY THE BODY WITHIN THE FIELD OF SAID MOVABLE ELEMENT FOR THE MAGNETIC ATTRACTION OF THE ELEMENT TO ONE OF ITS POSITIONS, A SECOND MAGNET SLIDABLY MOUNTED ON THE TOOL BODY FOR MOVEMENT INTO AND OUT OF FLUX LINKING RELATION WITH SAID POLE PIECE MEANS, SAID SECOND MAGNET HAVING ITS POLES ARRANGED TO REPEL SAID MAGNETIZED ELEMENT FROM SAID ONE OF ITS POSITIONS WHEN THE SECOND MAGNET IS IN SAID FLUX LINKING RELATION, AND TUBING STRING ENGAGEABLAE MEANS ON THE SECOND MAGNET TO EFFECT SLIDING OF THE SECOND MAGNET OUT OF SAID FLUX LINKING RELATION INCIDENT TO REVERSAL OF DIRECTION OF TOOL TRAVEL WITHIN A TUBING STRING.