US2572895A - Safety sub jar assembly - Google Patents

Description

O ct. 30, 1951 K. E. WAGGENER 2,572,895

SAFETY SUB JAR ASSEMBLY Filed Feb. 21. 1947 Patented Oct. 30, 1951 UNTED AfSlYff-Es SAFETY 4 Claims. 1

This invention is a sub for use in deep well drilling tool strings.

The current practice in deep well drilling is-to make up a bit and drill collar assembly the latter being of desired predetermined weight to drive the bit down as fast as it cuts'without weight of the suspended rotary tool string and the instant in'- vention has for an object the provision of a safety sub or joint assembly to be incorporated in the tool string at a locationepreferably just above the drill collar and which sub is adapted to be readily disconnected within itself to permit the string (of drill pipe) to be safely recovered-from the well hole in event that-fthe bit or the collar` becomes frozen and is not pullable from the hole.

A further object of the invention is to provide a telescopic subvin'which there is incorporated-a device which automatically` effects the relativejamming of the cooperative sub parts-in such a manner that these parts are rigidlystabilized ina manner highly desirable in this form of jointsub.

The invention has the additionalv object of-providing a sub in whicha mandrel and avcomplementary barrel are provided with cooperative interlocking features which enable the sub parts'itobe readily interconnected for suspension of the attached drill collar` and rotationaldrive thereof without need of a screwingY torquefand'without setting up av reverse torque withinthe'suU-"when it is to be broken ordisconnected toirl'e'a he string from the collar for any reason, and wlic particularly, will not unlock from the mandrel ing event of back lash from avtwisteddrillstring.

The invention has the furtherobjec'itivey of lproviding a safe and reliable means for automatii' weight so that the suspended collar can bepus'hedl down past minor obstructions ina hole"w'ithout= the hazard of tripping open the sub joint, andin-f which increased load can be used on the drill it is an object to provide a yieldablelaftc'hingv means which will automatically giveway' wheiif the string load on the drive element-'of thelsb exceeds the additive'load predetermined'bythe?- latch means, and to provide alatching means? which will repeatedly set itself as'tothemandr'e l and will .repeatedly give Way in themanne stated.

Also an objectof the-invention-is -to 1p1-avide: 55: the-barrelfinterlockin ftheflslots 8k (o1. 25542715 atippabie an'dlseifati Vg ratei1f-rimane;opfer teaiiwtheuniatched barrel-tube munitegrammi`- repeatedly oriL an a'rrvlpart of theIiaridel*lolif4v jarring functions at" will; the sub'having capacity for upwardly bumping the tool as may be needed at times. n

invention'i residesl inl certain advancements inv this art; asset-fortli-'inithe ensuing disclosure arid'- i'aviil'g,L With the aovf additDIlaL-l Objct'f and advantages asf hereinafter f dvel'opd'f" and*- vv'lfiose constructions, combinationsandA slibco'm'e" binatiris"and-details of r'ansand" theman' of' operation willbemade manifestl inthe* following descriptionA ofL the herewith illustrati embodiment; it-beirig' uiderstodditliatimodic en' tions,- variations 4and adaptations may be resorted to within the scopa-spirit andprinciples"ofthei ir'vention' a's it-` is`v claimed iii-conclusion lieref A Figure l is anV axial sectionV 0fv tlfiefsub' normal driven positionV ofVVV the mandrelA and-itsA barrel lowered tolthe breaking or decltcHed-'A position drivthev lnia'ridilerea'dyforl'lefti handitur and barrelV pulling operation for detachme'iitifrrr theinandrel. y 4 ,l

FigurefB'is acrosssectionon line 3-32 Figi?? Figure-- 4 is"` a 'cross-section; -on largerl scalej -gorifline 4 4; Figv. 1. v The joint subshown'- includes avbfoctp attaching to the pirendofY a-portioofi-a l pipe string?, and has acetralmandrel' 3-wit a screw pin` 4attaching-to'thetcp endof?-a` -c`Irill' collar C; the weightofwliclris'fu'sedf` tiv forcefdown a bit not shown: Vj Y Usually the tool-freezes' at' a" level'belowfth string subA and the instant-invention providesffoiv normal drive, that -is rig'lithand-rotatin, o'fltli t* drill collar by the tool ls'tring; and in needf'toith right (looking down fromthe'top); for-'thereleaseA of the string from thefrozer-c'ollar. y

Screwed onto the 'bok '2\is"t`l`e upper en barrel 5 whosel lower edjte'lescpesfont duced, complementary bodyV 3io: of the "sub drel and is' adapted to bump down-ohahahvilf forming shoulder. A of the mandrel.- The bore face of the barrel is provided with svt of longitudinal keys 6' having" obliquetfjenlca'facis l 6] Which are adapted-to jam againstcomplf' mal lowering or elevating operations of the mandrel and attached tool parts the keys suspend the load from the barrel.

If, during lowering of the mandrel, it should hang in the hole the barrel can be relatively lowered to set the keys 6 in complementary pockets I I longitudinally below the slots 8 until the hammer end H of the barrel bumps the anvil shoulder A of the sub 3. This down bumping action may effect release of the mandrel from the wall of the formation hole and lowering and drilling can proceed. Y

1f for any reason the mandrel becomes frozen the barrel is elevated until the keys 6 reach an intermediate position and register with escape channels I2; one for each key, formed along the sides of the splines I0 of the mandrel to their upper ends. This entirely disconnects the barrel from the frozen mandrel for free extraction from V the formation hole. It will be seen that a slight left hand rotationof the barrel to bring its keys laterally'into the channels I2 can be accomplished without any danger of an unscrewing torque on the screw joints of the tool string.

Mandrel latching means Y a It is an object to maintain a desired additive degree of pressure on the bit in an `amount some-Y what greater than theweight of thedrill collar and to provide for the automatic tripping of the barrel when an excess additional pressure over that desired has been set on the collar and its bit.

Pjor this purpose the mandrel body 3x is extended up throughra joint packing device I5 mounted on the, bore face of the barrel and is provided with a low angle, conical rim shoulder I6'of the said body.; A circle of heavy duty, spring-material latches II extend down from and are integral with a collar I8 iittingV in the barrel and screwed onto the lower, end of the top box 2 and these latches normally spring inwardly atptheir lower ends to abut the complementary shoulder I6 of themandrel. The outward pitch of. this shoulder determinesthe degree ofV load from the barrel string that can be added to the Thus if A,an extra down p ressurerof fifteen tons be idesired then the conic angle ofthe llatch bearing shoulder I6 will be made to such pitch as willinstantly press the spring latches outwardly enough to clear the body 3m and the barrel and its string'will befree vfor downshiftY as to the mandrel. This detachment can be observed by the usual weight meter at the drill table.

The barrel can now be bumped up and down onhthe mandrel, and the extra pressure will be put on the mandrel eachtime the latches automatically close on the shoulder I6. When it is found that the mandrel cannot be jarred loose for further down feed, or cannot be pulled from the hole under a safe string strain thenvthe operator simply reverses normal righthand rotation and brings the keys into the escape channels I2 and elevates the barrel and strings; leaving the stuck mandrel for fishing operations.

Barrel stabilizing means In joints of the sub type `vibrations of the barrel and the mandrel, relatively, involve dangerous hazards and the instant invention` provides for the effective elimination of such vibrations. Referring to Fig. 4 it will be seen that R, and the coordinate face Ba: of the adjacent key 6 is angled to snugly dove-tail with the spline face I. Therefore, when the top end face Bf jams on face 'I of the hook slot the dove-tail keys will be solidly wedged by the faces Ix and lost motions of the mandrel as to the barrel nullifled.

What is claimed is:

1. A safety-joint well tool comprising, in combination, a cylindrical mandrel provided at its lower end withl circumferentially spaced first splines each having at its upper end a downwardly extending smaller second spline attached thereto and spaced therefrom, the portion interconnecting said rst and second splines having a. downwardly extending transverse cam face formed thereon, a tubular barrel member telescopically'and rotatively mounted on said mandrel and having key members formed on its lower end and projecting inwardly and slidably fitting in the spaces between the splines, whereby each of said key members is rotated by said barrel member into registry with the space between a rst and a second spline, the upper surface of said key members having a complementary cam face to engage with the said transverse cam Vface and suspend the mandrel from thev barrel member during operation of the tool in a well hole, releasable locking means at the upper end of the mandrel yieldably urging said key members upwardly and releasably locking the barrel to said mandrel, said means comprising a collar 45 weight of the collar working on the cutting bit.,

theside face Illx of the several splines I0 towardl fixedly connected to said barrel member and having a series of downwardly extending and inwardly converging spring latch members integral therewith, the lower ends of the latch members being bevelled downwardly and outwardly, said mandrel having on its upper portion a latch tripping cam face on which said latch ends engage, said mandrel and said barrel member having cooperative anvil and hammer. faces respectively formed thereon, said hammer face impacting upon said anvil face when sufcient downward pressure is applied to said barrel member to overcome the resistance of the rlatch members on the latch tripping cam face of said mandrel and to move the latch members outwardly to allow for downward movement'of said barrel member on said mandrel.

2. `The tool of claim l; and in which the collar connection to the barrel member consists of a box screwed into the barrel member and to which box the upper end of the said collar is affixed for insertion or removal by and with said box.

3. A safety jointjar assembly comprising, in combination; a cylindrical mandrel provided at its lower portion with circumferentially spaced, longitudinal, elongated, main splines each connected at its upper end to a downwardly directed, shorter spline laterally spaced from the upper portion of its respective main spline and forming therewith a slot which is closed at its top by a transverse land face at the connecting portion of the relative splines, a tubular barrel member telescopically and rotatively mounted on said mandrel and having peripherally spaced 'keys rigidly attached to its interi-or face and slidably meshing in the'spaces between the main splines; whereby saidV keys are concurrently rotated by and .with the barrel member into registry with the said slots so that the upper ends of the keys may be mutually engaged with the coordinate land-faces at -the tops of the said slots and suspend the mandrel during operation in a well hole, releasablelocking Vmeans at the upper end of 5 the mandrel yieldably urging said keys against said land faces and thereby locking the barrel member to said mandrel; said means including a collar xedly connected to the barrel member 4. The assembly of claim 3; the said land faces and the top end faces of the keys being inclined transversely to the axis of the barrel member whereby to exert a turning action as between and having a series of downwardly extending 5 the mandrel and the barre1 member.

and inwardly contracting spring latch fingers integral therewith and whose lower ends are bevelled downwardly and outwardly, said mandrel having on its upper portion a latch tripping cam face on which said spring latch iingers engage, said mandrel and said barrel member having cooperative anvil and hammer faces respectively formed thereon, said hammer face impacting upon said anvil face when suiflcient downward pressure is applied to said barrel member to overcome the resistance of the spring ngers on said cam face of the mandrel and to force the said lingers outwardly to allow for downward shift of said barrel member along the mandrel.

KENNETH EDWARD WAGGENER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,833,144 Wickersham Nov. 24, 1931 1,954,513 Beck Apr. 10, 1934 2,065,135 Huddleston et al. Dec. 22, 1936 2,158,406 Collett et al. May 16, 1939 2,309,866 Reed Feb. 2, 1943 2,354,709 Shaffer Aug. 1, 1944

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