US2179567A

US2179567A - Deflecting device for well drilling tools

Info

Publication number: US2179567A
Application number: US235311A
Authority: US
Inventors: Thomas C Strength
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-10-17
Filing date: 1938-10-17
Publication date: 1939-11-14
Anticipated expiration: 1956-11-14

Description

NOV. 14, 1939. T, Q STRENGTH 2,179,567

DEFLECTING DEVICE FOR WELL DRILLING TOOLS Filed Oct. 17, 1938 atente 2,179,567 v A v nnrtnc'rnro nnvicn ron wnnnnnl noa 'rooms Thomas C. Strength, lLong Beach, Calif.

Application October 17,

17 Claims.

This invention relates to well drilling tools and relates more particularly to a device for deflecting rotary well drilling tools. A general object of this invention is to provide an eiective, practical and dependable deflecting tool for use in directional well drilling operations.

In the drilling of oil wells and gas wells it is often desirable to divert the course of the well or to increase the deviation of the well from the vertical in a given direction, to reach arproductive formation. Such controlled directing or diverting of a well is termed directional well drill- Another object of this invention is to provide a directional well drilling device for use in connection with a rotary Well drilling string that is operable to direct or divert the drilling tool to advance or drill in a selected direction.

Another object of this invention is to provide a deflecting tool of the character mentioned that embodies a novel projectable or expansible means contactable with the wall ofthe well to effect the deflection of the drilling tool.

Another object of this invention is to provide a deecting device of the character mentioned that includes a universal joint permitting deection of the drilling tool without excessive bending of the drilling string.

Another object of this invention is to provide a deecting device of the character referred to that may be easily and quickly run into the well on the drilling string without danger of premature actuation or expansion.

Another object of this invention is to provide a deflecting device of the character mentioned that is automatically retracted when the drilling string is pulled from the well.

Another object of this invention is to provide a delecting tool of the character mentioned that is automatically oriented in an inclined well bore to deilect the drilling tool to increase the deviation of the well from the vertical or to maintain the selected deviation of the well.

l-.nother object of this invention is to provide a delecting device of the character referred to that may be set or adjusted to cause deviation of tile hit to the right or left from its former incnned course.

further object of this invention is to provide a tool or. device of the character mentioned that'is simple and easy to control and operate.`

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout 1938, Serial No. 235,31ll

which description reference is made to the companying drawing, in which:

Fig. lis a side elevation of the tool or apparatus of the present invention in position in a well Withthe deiiecting means in its contracted condition. detailed sectional view of the deflecting device showing .the expansibleelement in its projected; position. Figs. 3, 4 and 5 are enlarged transverse detailed sectional views taken as indicated by lines 3`-3, 4 4 and 5 5, respectively, on Fig. 2, and Fig. 6 is an enlarged transverse detailed sectional view taken as indicated by line 6 6 on Fig. l.

The deecting device of the present invention -is intended for use in a rotary well drilling string and in accordance withthe invention may be employed in connection with rotary well drill' ing-tools of variousinatures and classes.v In the following fdetailed description I will describe a typical', preferred form of the invention operating in' connection with a typical well drilling tool, it being understood that theV invention is not to ,be construed as limited or restricted to the specie form or application of the invention about to be described.

The directional well drilling apparatus of the present invention may be said to comprise, generally, a rotary well drilling string S, a drillingtool T on the lower end of the string S and a deiiecting means interposed in the string S comprising two sections A-and B connected for relative angular and longitudinal movement, a sleeve C rotatably carried'by one of said sections, and a deflecting means lll on the sleeve C expansible into cooperation with the Wall of the well W upon relative longitudinal movement between the sections A and B.

The rotary well drilling string S is a tubular fluid conducting assembly of rotary drill pipe for carrying and operating the drilling tool T. The string S may be made up of lengths of drill pipe connected by couplings and tool joints in the well known manner. The drilling string S extends upwardly to the well derrick where it is handled by the rotary and the hoist equipment of the rotary well drilling rig (not shown). The drilling tool T is provided to drill into the earth formation to vform or deepen the well W. Any suitable or required form of drilling tool may be employed. In' the typical case illustrated the tool T is in the nature of a drag type bit of the well known fish-tail class. A suitable coupling il connects the stem of the bit or tool T with the lower section of the drilling string S. The

Fig. 2 vis an enlarged longitudinal.

tool T is operable to drill the well W to suicient gauge or diameter to pass the string S with suitable clearance leaving a space for the return Iiow of' the circulation fluid.

The sections A and B are connected or interposed in the string S at a point spaced a selected distance above the drilling tool T. The sections A and B are telescopically related, the section A being in the nature of an inner section or mandrel section and the section B being in the nature of a outer section receiving an end portion of the mandrel section A. In the preferred arrangement illustrated the mandrel section A is the upper -section and extends downwardly into the outer section B.

The inner or mandrel section A is an'elongate tubular member having a. central longitudinal fluid passage I2 extending through it from one end to the other. An adapter I3 is threaded on the upper end of the section A and a tool joint section I4 connects the adapter I3 with a sec- 4tion of the drilling string S.- @The upper portion of the mandrel section A is cylindrical while the lower portion of the section A is polygonal in external conguration. An outwardly projecting annular flange I5 is provided on the section A between its cylindrical and polygonal upper and lower portions. A head I6 is threaded or otherwise secured to the lower end of the mandrel section A. The head I6 has a convex or substantially spherical external lower surface l1.

The section B is a tubular member whose longitudinal opening I8 is suciently large in diameter to receive the polygonal portion of the section A with substantial clearance. The section A extends downwardly into the upper end of the section B. An internal flange i9 is provided in the section B adjacent its upper end and has a polygonal opening 20 passing the polygonal portion of the section A with clearance. The cooperation of the polygonal portion of the section A with the opening 20 provides for the transmission of rotation between the sections A and B and prevents relative turning between the sections while the clearance allows relative angular movement between the sections. A downwardly facing grooved and expansible packer 2Iv is provided in the opening I8 above the ange I9. A nut 22 is threaded in the upper portion of'the opening I8 and the packer 2l seats upwardly against the lower end of the nut. The packer 2I is expansible by fluid pressure within the opening I8 to seal between the sections A and B.

The lower end or' the outer section B has a tiltable connection with the string S. A tubular nut 23 is threaded in the lower end of the opening I8 and has a polygonal opening. A stem member 24 passes through the nut 23 and enters the opening I8. The member 24 has a polygonal portion passing through the polygonal opening of the nut 23 with clearance. An adapter 25 is threaded on the projecting lower end of the member 24 and a tool joint section 26 connects the adapter 25 with the string S. An annular iange 21 is provided on the member 24 above the nut 23. The ange 2'! is engageable with the upper end of the nut 23 and the adapter 25 is engageable with the lower end of the nut 23 to limit the relative vertical movement between the section B and the member 24. The connection just described connects the section B with the string S against separation and for the transmission of turning forces, and yet allows relative angular movement between the section B and the string. An expansble grooved packer 28 engages about the member 24 above the flange 2. The packer 28 is expansible by uid under pressure in the opening I8 to seal between the section B and the member 24.

A head 29 is provided on the upper end of the stem member 24. The head 29 has a socket or seat 30 in its upper end adapted to receive the lower portion of the head I6. A central longitudinal opening 3| extends through the stem member 24 from the upperl end of its head 29 to the uid passage in the adapter 25. The surface Il of the head I8 is adapted to bear in the seat 30 to seal with the seat and to transmit downward forces between the mandrel section A and the stern member 24. The engagement of the head I6 in the seat 30 is such that the mandrel section A may have angular movement with respect to both the section B and the stem member 24. Itis to be observed that the lower 'end of the opening I2 in the section A directly communicates with the upper end of the opening 3| in the stem member 24 so that fluid is directly transmitted from the section A to the member. Any fluid that may leak past the engaging surface I1 and seat 30 is prevented from leaking from the opening I8 by the packers 2| and 28. The head I 6 on the lower end of the section A is engageable with the seat 30 and the lower end of the flange I9 to limit the relative vertical movement between the sections A and B and to prevent the separation of the sections. The heads I6 and 29 have clearance with the wall of the opening I8 and are shaped to permit substantial relative angular movement between the sections A and B and between the section B and the stem 4 member 24.

The sleeve C is provided to carry the deflecting sleeve C surrounds the upper portion of the section A above the section B. The sleeve C is .an elongate tubular member surrounding the cylindrical upper portion of the section A with suitable clearance. In the form of the invention illustrated the sleeve C is internally recessed or hollowed out so that its inner surface is spaced some distance from the section A. The upper and lower end portions of the sleeve C may pass the member A with but slight clearance.

The sleeve C is supported on the section A by anti-friction bearings so that it may remain nonrotatable during the drilling operations. An anti-friction ball bearing 34 is arranged at the upper end of the sleeve C and bears upwardly against the lower end of the adapter I3. A similar ball bearing 35 is provided at the lower end of the sleeve C and bears downwardly against the flange I5. The

bearings

34 and 35 are designed to transmit both radial and axial thrusts to fully support the sleeve C on the section A. 'I'he means I0 is expansible or projectable into cooperation with the side wall of the well W to effect or maintain the deection of the well drilling tool T and the adjacent lower portion of the string S.. The means I0 is carried by the sleeve C and in the particular construction illustrated is supported on the lower portion of the sleeve.

In accordance with the invention the means I0 includes a wedge element 36 secured to the sleeve C and a wedge element or slip 31 shiftably cooperating with the wedge element 36. In the preferred construction the wedge element 36 is shiftable or adjustable to any one of a plurality of different rotative positions on the sleeve C. The sleeve C has three circumferentially spaced dove-tailed grooves 38. The wedge element it is shaped to fit or lie against the sleeve C and has a dove-tailed tongue 36 adapted to seat in any one of the grooves 38. A lug 39a is provided on the upper end of the wedge element 36 and a set screw mi passes through an opening in the lug 39a and threads into one of a plurality of openings il in the sleeve C to hold the wedge element 36 against detachment from the sleeve C. The lower end of the wedge element 36 may bear downwardly against the bearing 35. In the drawing I have shown the tongue 39 engaged in the intermediate groove 38 so that the wedge element 36 is in an intermediate position. It is to be understood that the tongue 39 may be arranged in either of the other grooves 38 to provide for the deflection of the tool T in the selected direction as will be more fully describedl- The outer side of the wedge element 36 has a flat downwardly and inwardly inclined surface t2. The wedge element or slip 31 is the active formation engaging part of the means IIJ and is expansible through cooperation with the element 36. The slip 31 has a flat downwardly and inwardly inclined surface 63 slidably engaging on the surface 42. A sliding dove-tailed tongue and groove connection M is provided between the wedge element 35 and the slip 31 to prevent the loss or displacement of the slip from the wedge element. The outer 4side of the wedge element or slip 31 is shaped to conform, generally, to the wall of the well W and is provided with vertically extending ribs 45 adapted to embed themselves in the wall of the well to prevent turning of the means l0 in the Well. The upper ends of the wedge element 36, the slip 31 and the lug 39a preferably slope downwardly and outwardly.

The invention 'may include means for automatically orienting the means l0 in an inclined well to provide for the increase or the maintenance of the inclination or deviation of the well from the vertical. more weights associated with the sleeve C. In the construction illustrated a weight 46 is provided in the sleeve C. The weight 46 may be in the nature of a body of material of a high specific gravity such as lead, babbitt, or the like. The weight d6 may be cast in the sleeve or may be otherwise secured in place. The weight 46 is provided to render the sleeve C dynamically eccentric and its weight is suicient to overcome the weight of the means I6 and the parts associated therewith. The weight 46 is located at one side of the axis of rotation of the sleeve C and opposite the series of grooves 38. In practice the weight Lit may have its vertical axis directly opposite the vertical axis of the intermediate groove 38. Thus where the means I0 is positioned as illustrated in the drawing, the weight i5 is directly opposite the means lll. Assuming that the device is in an inclined well and that the sleeve C is free for turning with respect to the section A, the weight [i6 gravitates to the low side of the well Vif causing the sleeve to to a position where the means lll is at the high side oi' the well. Thus the weight 56 is operable to automatically orient the means i6 in an inclined well to cause the drilling tool T to maintain or increase the inclination of deviation oi. the wel?. from the vertical.

A control or actuating means is provided to govern the deiiecting means i6. A downwardly projecting tail it is provided on the slip 31 and a yoke projects inwardly from the tail to engage in an annular groove il? in the above de- This means includes one or scribed nut 22. The yoke 50 engages in the groove t1 with suitable clearance. The engagement of the yoke 50 in the groove 41 holds the slip 31 against vertical movement relative to the section B so that downward movement of the section A with respect to the section B may result in projection or actuation of the slip 31 and upward movement of the section A relative to the section B may cause retraction of the slip 31.

Latch means may be provided for releasably holding the sleeve C and the means lll against rotation relative to the section A whereby the means I 0 may be oriented by manipulation of the strong S. A latch 52 is pivotally secured in a groove 53 in the tail 49. A suitable pin 56 may pivotally support the latch 52 on the tail 49. The latch 51 has Aaninwardly projecting finger 55 on its lower end en'gageable in a notch 56 in the section B. A leaf springl 51 on the tail 49 yieldingly holds the latch 52 in Aa position where its finger 55 engages in the notch 56. The parts are formed and related so that the latch nger 55 engages in the notch 56 when the sections A and B are in the extended positions. The engagement of the finger 55 innthe notch 56 prevents turning of the sleeve C andthe means Il] relative to the section A. The latchfinger 55 is free to move out of the notch 56 when the section A is moved downwardly with respect'to the AsectionB to actuate the means |0. Y Y

, In the use or operation of the apparatus of the present invention the deflecting tool may be connected in the string S as illustrated in Fig. 1 of the drawing, and the string maybe run into the well W. The means Illis i'n the contracted condition shown in Fignl of thedrawing when the string. S is loweredinto the well W so Athat the slip 31 freelycl'earsgthe wall of thel well. The latch nger 5 5 er'1' 'g,a'fg1es in the: notch 56 to hold the means I0 'and thegsleeveC in agiven rotative position with respect to thestring S. The string S is manipulatedto bring the tool Tv to a position a short distance above @the bottom fof the well W and, if necessary, the string S may be manipulated `to orient the means-l0, that is, to bring the means I0 tof rayjfgiven rotative position.' The means fullydescribed and claimed in my copending application entitled Directional well drilling. tool, filed October 17, 1938, Serial No. 235,312, may be employed in connection with the orientation of the means l0. If desired the weight 116 may be dispensed with or may be reduced to merely counterbalance the means I6 when oriented as above. In the event that the well W is inclined from the vertical and it is desired to maintain this inclination or to increase this inclination the means I6 may be automatically oriented by the weight 46. In the latter case the release of the latch 52 is immediately followed by the automatic turning of the sleeve C by the gravitational action of the weight t6.

When it is desired to release the latch'52 and actuate the means lil following the orientation of the means lll by manipulation of the string S' or preparatory to the automatic orientation of the means ill by the weight 'i6 the string S is lowered or moved downwardly to engage the tool T against the bottom of the well. Subsequent downward movement of the string S results in downward movement of the section A with respeci: to the section B. The engagement of the yoke 5l] in the groove il holds the slip 31 against downward. movement and the surface Il? on the downwardly moving wedge element 36 engages the surface i3 to move the slip 31 outwardly.

This outward movement of the slip 31 is accompanied by the release of the latch linger 55 from the notch 56 and where the weight 46 is utilized to orient the means I0 the sleeve C turns with respect to the section A by gravity to the position where the weight 41 is at the low side of the inclined well bore. During further downward movement of the string S the cooperating surfaces 42 and d3 expand or proiect the slip 31 to a position where it engages against the side wall of the well W. This engagement of the slip 31 with the wall of the well W moves the sections A and B and the adjacent portions of the string S laterally so that they are oiset from the central vertical axis of the well W.

The downward movement of the section A with respect to the section B resulting from the above described downward movement of the string S is limited by the engagement of the head surface I1 with the seat 30. When the head surface I1 bears in the seat 30 the required or desired downward pressure may be applied to the tool T and the string S may be rotated to cause the tool to drill into the earth formation. The slip 31 bearing on the side Wall of the well W holds the sections A and B and the adjacent portions of the string S in an eccentric relation to the longitudinal axis of the well W so that the tool T is diverted or made to drill an inclined hole. 'I'he connection between the sections A and B and the connection between the section B and the member 2d provides for relative angular movement between the parts to relieve the lower portion of the string S of excessive bending forces. The portion of the string S between the tool joint section 26 and the coupling |.I is preferably limber to flex and permit the desired angular drilling of the well.

During the rotary drilling operation the engagement of the slip 31 with the side wall of the well W holds the sleeve C against turning. The

bearings

34 and 35 allow the sleeve C to remain nonrotatable during rotation of the string S. When the well W has been drilled to the desired depth or when it is desired to withdraw the string S from the well the string is raised to release or retract the means l0. Upward movement of the wedge element 36 with respect to the slip 31 is accompanied by retraction or inward movement of the slip so that the upward movement of the string S automatically retracts the means l0. The yoke 50 engaging in the groove 41 holds the slip 31 against upward movement during the upward movement of the string S and section A.

The deecting means l0 may be adjusted or set to provide for the deflection of the drilling tool T to the right or to the left from a previous inclined course. The tongue 39 on the Wedge element 36 may be arranged in either one of the side grooves 38 to provide for this action of the means l0, assuming that the device is provided with the weight 46, as described above. It will be seen that the arrangement of the tongue 39 in one of the side grooves 38 locates the means I0 at substantially 90 from the vertical plane of the weight 46 and when the Weight 46 turns the sleeve C the means l0 is brought to a position Where it provides for the deection of the tool T to the right or to the left of its previous inclined course.

Having described only a typical preferred form and application of my invention I do not wish to be limited or restricted to the specic details herein set forth, but Wish to reserve to myself any variations of modifications that may appear to those skilled in the art, or fall within the scope of the following claims:

Having described my invention, I claim:

1. A device for deflecting a well drilling tool carried by a drilling string comprising a member connected in the string above the drilling tool and having an inclined surface, and a slip shiftable on said surface to be engaged against the wall of the well by the surface.

2. A device for deecting a well drilling tool comprising a drilling string carrying the drilling tool, a member connected in the said string to be run into and out of the Well thereon, the member having an inclined surface, a slip shiftable on said surface to be projected laterally against the side wall of the well, and means for effecting relative movement between the member and slip to project the slip.

3. A device for deflecting a well tool carried by a well string comprising a section connected in the string, a sleeve rotatably supported on the section, an inclined surface on the sleeve, a wedge element shiftable on the surface to be projected thereby into contact with the wall of the well, and means for actuating the wedge element.

4. A device for deecting 'a well drilling tool carried by a well string comprising two sections related for limited relative longitudinal movement, means connecting the sections in the string above the drilling tool, an inclined part on one section, a wedge element shiftable on said part to be expanded laterally against the wall of the well at one side of the well to deflect the string from the central longitudinal axis of the well, and means for holding the wedge element against longitudinal movement relative to the other section whereby relative movement between the sections results in projection of the element.

5. A deflecting tool for use in conjunction with a well drilling string comprising two sections connected in the string for relative longitudinal movement and for relative angular movement and for movement into and out of the well on the string, an inclined part on one section, and a slip shiftable on said part and projected laterally thereby to engage the wall of the well to deflect the string upon downward movement of one section relative to the other, the slip including vertih cal teeth for engaging the wall of the well.

6. A deflecting tool for use in conjunction with a well drilling string comprising two sections connected in the string for relative longitudinal movement and for relative angular movement, a Sleeve rotatably carried by one section, a wedge element secured to the sleeve, a slip slidably keyed to the wedge element to be projectable thereby, and means holding the slip against downward movement relative to the other section whereby the slip is projected upon downward movement of the rst mentioned section.

7. A deecting tool for use in conjunction with a well drilling string comprising two sections connected in the string for relative longitudinal movement, a rotatable sleeve on one section, means on the sleeve operable against the wall of the well to deflect the string, and a weight on the sleeve at one side of its axis of rotation for orienting the sleeve and said means in an inclined well.

8. A deflecting tool for use in conjunction with a` well drilling string comprising two sections connected in the string for relative longitudinal l movement, a rotatable sleeve on one section, projectable means onthe sleeve engageable with the wall of the well to deilect the string, weight means carried by the sleeve for orienting the projectable means when the string is in an inclined Well, and

means for projecting the projectable means upon relative longitudinal movement between the sections.

9. A deecting te \l for use in conjunction with a well drilling string comprising two sections connected in the string for relativej longitudinal movement, a sleeve rotatable on one section, a weight on the sleeve at one side of its axis of rotation, a wedge element, means for securing the wedge element in any one of a plurality of positions on the other side o the sleeve, a slip slidably engaging the wedge element to be projectable thereby, and means' for holding the slip against downward movement relative to the other section whereby downward movement of the iirst named section causes projection of the slip, the weight serving to orient the wedge element and slip in an inclined well.

10. A deflecting tool for use in conjunction with a well drilling string comprising two sections connected in the string for relative longitudinal movement and for relative angular movement, a sleeve rotatably carried by one section, a wedge element secured to the sleeve, a slip slidably keyed to the wedge element to be projectable thereby, means holding the slip against downward movement relative to the other section whereby downward movement of the first named section causes projection of the slip, and latch means holding the sleeve against turning relative to the said rst named section releasable upon projection of the slip.

ll. A delecting tool for use in a rotary Well drilling string comprising a tubular outer section, means connecting one end ofthe outer section with the string for angular movement relative thereto, an inner section having one end extending into the other end of the tubular outer section, means connecting the other end of the inner section with the string, the sections being related for limited relative longitudinal movement and for limited relative angular movement, and means carried by one of the sections projectable laterally therefrom upon relative movement between the sections to deflect the string.

12. A deflecting tool for use in a rotary welll drilling string comprising a tubular outer section, means connecting one end of the outer section with the string for angular movement relative thereto, an inner section having one end extending into the other end of the tubular outer section, means connecting the other end of the inner section with the string, the sections being related for limited relative longitudinal movement and for limited relative angular movement, a rotatable sleeve on said inner section, and means carried by the sleeve projectable laterally upon relative longitudinal movement between the sections to deflect the string.

13. A deflecting tool for use in a rotary well drilling string comprising a tubular outer section,

means connecting the lower end of the outer section with the string comprising a stem member secured to the string and entering the lower end of the outer section with clearance, a mandrel section entering the upper end of the outer section with clearance to have limited longitudinal and angular movement with respect thereto, ball and socket parts on the mandrel section and said member providing for the transmission of downward forces and providing for angular movement between the mandrel section and member, a sleeve rotatable on the mandrel section, a wedge part on the sleeve, a. slip operable along the wedge part, and means for holding the slip against downward ymovement relative to the outer section whereby the wedge part projects the slip laterally upon downward movement of the mandrel`section relative to the outer section.

14. A deiiccting tool. for use in a rotary well 4drilling string comprising a tubular outer section,

means connecting the lower end of the outer section with the string comprising a stem member secured to the string and entering the lower end of the outer section with clearance, a mandrel section entering the upper end ofthe outer section with clearance to have limited longitudinal and angular movement with respect thereto, ball and socket parts on the mandrel section and said member providing, for the transmission of downward forces and providing for angular movement between the mandrel section and member, the mandrel section and said member having fluid passages communicating at said ball and socket parts, packing elements sealing between the outer section and the mandrel section and said member, a sleeve rotatable on the mandrel section, a wedge part on the sleeve, a slip operable along the wedge part, and means for holding the slip against downward movement relative to the outer section whereby the wedge part projects the slip laterally upon downward movement of the mandrel section relative to the outer section.

15. A deflecting tool for use in conjunction with a well drilling string comprising two sections connected in the string for relative longitudinal movement and for the transmission of rotation, universal joint means connecting the sections for relative angular movement, a sleeve rotatably carried by one section, a wedge element secured tothe sleeve,i a slip slidably keyed to the wedge element to be projectable thereby, and means holding the slip against downward movement relative to the other section whereby the slip is projected upon downward movement of the first mentioned section.

16. A Ideflecting tool for use in a rotary well drilling string comprising a mandrel connected with one part of the string, a stem member connected with another part of the string, a tubular outer section connected with the stem meinber for relative angular movement and for the transmission of rotation, cooperating parts on the mandrel and outer section connecting the mandrel and outer section for the transmission of rotation and for relative angular movement and for relative longitudinal movement, universal joint means for transmitting downward forces from the mandrel to the stem member when the mandrel is in collapsed position relative to the outer section, means rotatably supported on the mandrel section yexpansible against the wall of the well, and means operable by downward movement of the mandrel relative to the outer section for expanding the expansible means.

17. A deflecting tool for use in conjunction with a well drilling string comprising two sections connected in the string for relative longitudinal movement, a rotatable sleeve on one section, means on the sleeve operable against the wall of the well-to deect the string, means operable by said relative longitudinal movement for actuating the last named means, and resettable latch means holding the sleeve against rotation releasable upon actuation of said last named means.

THOMAS C. STRENGTH.