US2100311A

US2100311A - Core drill

Info

Publication number: US2100311A
Application number: US14120A
Authority: US
Inventors: Alfred C Catland
Original assignee: Globe Oil Tools Co
Current assignee: Globe Oil Tools Co
Priority date: 1935-04-01
Filing date: 1935-04-01
Publication date: 1937-11-30
Anticipated expiration: 1954-11-30

Description

2 Sheets-Sheet l 5 4 3 3 4 w 7 m H ma w fly m mm W 2 NF Nov. 30, 1937. A. c. CATLAND CORE DRILL Filed April I, 1935 Nov. 30, 1937. A. c. CATLAND CORE DRILL Filed April 1, 1955 2 Sheets-Sheet 2 H a a 7 "a 3 $2.7 4 E /.3W& x flaw? 0 2 c 8- w a wwx W T x h a a a. y a x m@ C. E V0 NE W A ,4 TTOE/VEV Patented Nov. 30, 1937 UNITED STATES PATENT OFFICE cons mum.

Application April 1, 1935, Serial No. 14,120

16 Claims.

This invention relates to a well drilling tool and relates more particularly to a rotary well core drill. A general object of this invention is to provide a practical effective core drill embodying an improved and particularly efiicient core catching means or core recovering means.

Considerable diificulty has been "encountered in providing dog typecore catchers with dog actuating springs of the proper tension or strength. When the springs are too strong the dogs are pressed against the entering core with considerable force and destroy the core during the coring or drilling operation. On the other hand, when the core actuating springs are not of the required strength they do not provide for the proper operation or functioning of the dogs. Core catchers have been introduced in which the dogs or gripping parts are actuated by fluid pressure but difficulty is sometimes encountered in applying the proper fluid pressures for the different types of tool structures and earth formations.

Another object of this invention is to provide a core drill embodying a core recovering means in which the core gripping parts are dependably latched in retracted positions free of the core during the drilling'operation and may be readily released when desired to be positively actuated by an actuating means or control that insures their full effective operation.

Another object of the invention is to provide a core drill of the character mentioned in which the core catching means may be actuated without manipulating the drilling string and without special or complicated control of the circulation fluid. Another object of the invention is to provide a core catcher that is adapted to obtain a full sized unmutilated core. Another object of the invention is to provide a core drill in which the several core gripping and retaining dogs are operated by springs under the control of a novel latch. The dog actuating springs are normally held inoperative so that they do not urge the dogs against the core and, therefore, may be as strong as desired.

Another object of the invention is to provide a novel particularly effective core catcher comprising pivoted spring actuated dogs and a dog latching sleeve having gripping slips that aid the dogs in brealh'ng hard cores free from the formation and in retaining the freed cores.

Another object of the invention is to provide a core drill of the character mentioned that does not interfere with the free flow of the circulation fluid during the drilling operation or during the recovery of the core- Another object of the invention is to provide a core drill that includes a core catching or core recovering means that does not engage the core or interfere with the passage of the core into the drill during the drilling operation and that may be easily controlled or released for actuation from the well derrick.

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 which description reference ismade to the accompanying drawings, in which:

Fig. 1 is a side elevation of the drill provided by this invention, with the principal parts broken away to appear in vertical cross section showing the parts in the unactuated positions. Fig. 2 is an enlarged fragmentary longitudinal sectional view of the upper portion of the drill illustrating the inner barrel suspending means in a released condition. Fig. 3 is a transverse detailed sectional view taken substantially as indicated by line 33 on Fig. 2. Fig. 4 is an enlarged side elevation of the dog latching sleeve with a portion broken away to appear in vertical cross section. Fig. 5 is a. plan elevation of the sleeve. Fig. 6 is an enlarged vertical detailed sectional view of the lower portion of the drill showing the core catcher in the actuated condition and Fig. 7 is a transverse detailed sectional view taken substantially as indicated by line 1-1 on Fig. 6.

The core drill provided by this invention includes, generally, an outer barrel l carrying a bit head or cutter head I I, a normally inoperative core catcher l2 in the head ii, an inner barrel l3 shiftable to operate the core catcher l2, and releasable latchcontrolled means I4 rotatably suspending the inner barrel l3 in a position where the core catcher is unactuated.

The outer barrel I0 is an elongate tubular structure provided at its upper end with a sub l5. In the preferred form of the invention illustrated the sub has a pin I6 screw threaded into the upper end of the barrel ID. A screw threaded pin I! may project from the upper end of the sub l for connecting the drill with a drill collar or other part of a drilling string. The sub has a central longitudinal opening I8 for conducting the circulation fluid downwardly into the barrel I0. A sub or connecting member I9 is provided on the lower end of the outer barrel l0 and carries a bit head sub 20.

The bit head II comprises a body or shoe 2| screw threaded on the pin 22 of the sub 20. The invention contemplates the employment of any suitable or desirable form of cutting means on the head I In the particular case illustrated in the drawings the shoe 2| is provided with circumferentially spaced blades 23 having reduced teeth 24 on their lower inner parts. The blades 23 haveouter edges or reaming edges 25 and lower cutting edges 26.' The blades 23 operate to form an annular cut in the earth formation and the teeth 24 operate in advance of the blades and trim the core 0. The shoe 2| of the head I I has a vertical opening 21 which receives the core C with suitable clearance. The opening 21 is shaped or formed to carry the core catcher [2 to receive the lower end of the inner barrel l3. The opening 21 is of enlarged diameter intermediate its ends and its enlarged portion is graduated in diameter having an upper inclined shoulder 28, an intermediate shoulder 29 which may be normal to the longitudinal axis of the drill and a lower shoulder 39 which is inclined downwardly and inwardly. The wall portion of the opening 21 extending between the

shoulders

29 and 30 is preferably inclined downwardly and inwardly as illustrated in Figs. 1 and 6 of the drawings. An annular recess or groove .3| is provided in the wall of the opening 21 at the lower end of the pin 22. Spaced longitudinal ports 32 are provided in the wall of the shoe 2| and extend downwardly from the 'groove 3| to the lower end of the shoe where they discharge adjacent the blades 23.

The core catcher I2 is a feature of the present invention because it is normally free: or out of active contact with the core C during the coring operation and is adapted for positive actuation at the will of the operator or driller todependably recover and retain the core. The core catcher I2 is disposed in the enlarged portion of the opening 21 and includes an annular or tubular body 33. The core catcher body 33 may be sectional comprising two telescopically assembled ring sections.

The body 33 is free to turn or shift longitudinally in the opening 21 at will. The major upper portion of the core catcher body 33 is disposed above the shoulder 28 while the lower portion of the body 33 is adapted to project below the shoulder 28 and the body 33 may have a graduated or stepped periphery. An annular space or opening 34 occurs between the opposing faces of the sections forming the body 33. Spaced transverse openings 35 are provided in the wall of the body 33 and intersect the annular opening34.

In accordance with the invention core engaging dogs 36 are pivotally supported in the openings 35 to project from the inner side of the body 33. Pins 31 having their opposite end portions carried in the openings 34 extend through openings in the dogsiG to pivotally support the dogs in the openings 35. The dogs 36 as held re-- tracted in the manner to be hereinafter described normally project upwardly and inwardly into suitable notches or recesses in the inner side of the body 33 and the active ends of the dogs 36 are suitably sharpened. Notches or slots 38 are provided in the outer or lower ends of the dogs 36 to carry springs 39. The springs 39 surround the pins 31 and react against the body 33 and the dogs 36 to urge the dogs downwardly and inwardly to their active core engaging and retaining positions. In accordance with the invention the dogs 36 are normally held in their retracted positions and therefore the springs 39 may be made 'as strong as possible or as strong as desirable without danger of destroying the core 0. Cam parts 40 are provided on the dogs 36 and are. adapted to project outwardly through the opencooperation causes the dogs 36 to be pivoted v downwardly and inwardly into the core C.

The core catcher |2 includes a sleeve 4| which normally latches or holds the dogs 36 inoperative or retracted. The sleeve 4| is positioned within the core catcher body 33 and is proportioned to freely receive or pass the core C. The sleeve 4| projects upwardly beyond the upper end of the body 33 and its lower portion is provided with an external shoulder 42 engageable by the lower end of the body 33 when the body is shifted downwardly. Vertical or longitudinal slots 43 extend upwardly in the sleeve 4| from its lower end to make the lower portion of the sleeve flexible and contractible. Longitudinal windows or openings 44 extend upwardly in the sleeve 4| from its lower end. The dogs 36 are adapted to pivot or swing downwardly and inwardly through the openings 44 when the core catcher I2 is actuated or released for actuation. The active upper end portions of the dogs 36 normally engage the exterior of the sleeve 4| above the openings 44 to prevent the dogs from pivoting through the openings 44. The engagement of the spring urged dogs 36 with the sleeve 4| aids in holding the sleeve in position.

The lower portions of the sleeve 4|. which are separated by the slots 43 and the openings 44 are in the form of gripping slips S being provided on their inner sides with wickers or core engaging teeth 45. The outer surfaces 46 ofthe slips S are inclined downwardly and inwardly to cooperate with the inclined wall portion of the opening 21 and the shoulder 30 as will be hereinafter described. The slips S have upwardly facing shoulders 41 on their outer sides spaced below the shoulder 42. The shoulders 41 are engageable by the lower end of the core catcher body 33 after the slips S have been actuated inwardly against the core. A spring ring 48 is arranged in a groove in the inner sides of the slips S above the teeth 45 to urge the slips outwardly and aid in holding the sleeve 4| in position and in its normal uncontractedcondition. It is to be particularly noted that the core catcher l2 including its sleeve 4| does not actively engage the core C during the drilling or coring operation and, therefore, does not destroy or mutilate the core. I

The inner barrel I3 is arranged longitudinally in the outer barrel III to receive and hold the core C. The inner barrel |3 preferably has thin walls to be light in weight and is spaced from the interior of the outer barrel I0 to leave an annular the lower end portionof the inner barrel I3 and is rotatably received in the upper portion of the opening 21. The inner barrel [3 is free to rotate or to remain stationary during rotation of the drill and the collar- 5| is free to rotate and shift longitudinally in the opening 21. A hardened ring 52 may beprovided on the upper end of the collar 5| to bear. upwardly against the lower end of the pin 22 when the engagement of the core C with the inner barrel |3 tends to hold the inner barrel upwardly as the drill is fed into the formation. The opening in the collar 5| is enlarged at 53 to receive the projecting upper portion of the sleeve 4| and the projectingupper ends of the retracted. dogs- 36$ Ports 54 extend through the collar 5| to connect the passage 50 with the groove 3| so that the circulation fluid may passdownwardly from the passage 58 to the collar 5| is normally free of the core catcher body 33 as shown in Fig. 1 of the drawings but is adapted to bear downwardly against the upper end of the body 33 to release or actuate the core catcher.

A valve is provided on the upper end of the inner barrel l3 to allow fluid to be displaced from the inner barrel as it receives the core. The valve may include a tubular cage or body 55 positioned within the upper end portion of the inner barrel. The valve body 55 ls preferably releasably or detachably connected with the inner barrel. In the particular structure shown lugs 56 on the valve body 55 project into bayonet slots 51 in the wall of the inner barrel to connect the valve body with the inner barrel. A valve seat 58 is screw threaded in the lower portion of the valve body 55 and a ball 59 is adapted to cooperate with the seat to prevent the downflow of fluid through the valve. The ball 59 is retained against loss or displacement by a member 66 having a perforated web 6| extending across the mouth or upper end of the valve body 55.

The latch controlled means |4 normally sus pends the inner barrel l3 in a position where the core catcher I2 is unactuated. In the preferred form of the invention the means I 4 rotatably suspends the inner barrel from its upper end so that it may float or rotate at will. The means I4 includes a tubular member 65 slidable or shiftable longitudinally in the opening l8 of the sub l5. The upper end of the tubular'member 65 is open to the opening or passage l8 and ports 66 in the wall of the member carry circulation fluid to the upper end of the passage 50. The lower end portion of the tubularmember 65 is threaded and riveted or otherwise fixed to the member 60. The lower face of the tubular member 65 opposes the upper end of the valve body 55. An upwardly facing shoulder 61 on the member 60 opposes a downwardly facing shoulder 68 on the valve body 55. The valve body 55 is rotatable on the member 60 between theshoulder 61 and the lower end of the member 65 so that the

members

60 and 65 rotatably suspend the inner barrel.

' A latch I normally holds the tubular member 65 against downward movement and therefore holds the inner barrel l3 against downward movement and prevents actuation of the core catcher I 2. The latch I6 is positioned within an opening II in the wall of the member 65 and is pivotally supported by a pin I2. The latch III has a downwardly facing head or nose I3 for cooperating with the inclined lower wall of a groove It in the wall of the opening Hi. The groove I3 is preferably ntinuous or annular. A spring I normally urges the latch to the positionwhere its nose I3 cooperates with the wall of the groove I4. The cooperation of the latch I0 with the groove I4 holds the parts in the position where the inner barrel i3 is suspended as illustrated in Fig. 1 of the drawings where the lower end of its collar 5| is clear of the upper end of the core catcher body 33.

A comparatively heavy spring 16 may be arranged under compression between a shoulder 'II on the pin I6 and a shoulder I3 on the member 65 to urge the inner barrel I3 downwardly upon the release of the latch 16. The invention includes an object 30 adapted to be dropped through the drilling string to release the latch 10. The object 86 may be in the form of a sphere or ball. The latch I0 isprovided with a lug 8| which projects inwardly into the longitudinal opening 82 of the member 65. The ball or object 86 isproportioned to fit the opening 82 rather closely to engage the lug BI and pivot the latch III to free the latch nose I3 from the wall of the groove I4. The object 80 is adapted to come to rest on the web 6| where it does not interfere with the passage of the fluid downwardly through the opening 82 and ports 66.

In operation the drill is attached to the lower end of an operating string of drill pipe and is rotated and fed downwardly in the well in the usual manner. The parts of the tool are normally or initially in the positions illustrated in Fig. l of the drawings. As described above, the

cooperation of the latch II! with the groove I4.

suspends the inner barrel I3, through the

members

60 and 65, in a position where the lower end of its collar 5| is clear of the upper end of the core catcher body 33. The sleeve 4| positioned within the core catcher body 33 prevents the inward pivoting of the core catcher dogs 36. The blades 23 with their teeth 24 operate to form an annular channel or bore in the earth formation and leave the core C which is received in The circulation fluid is continuously pumped down through the drilling string under pressure to flow through the openings l8 and 82 into the fluid passage 50 and from the passage through the ports 54 and groove 3| to finally discharge from the ports 32.

After a core of the desired length has been cut or formed the ball or object 80 is dropped through the drilling string. The object 80 passes downwardly through the opening l8 and enters the opening 82. During its passage through the opening 82 the ball engages the lug 8| to pivot the latch I0 to its released position. Upon the release of the latch from the groove I4 the inner barrel l3 moves downwardly under the influence of the spring I6 and its own weight. Downward movement of the inner barrel |3 brings the lower end of the collar 5| against the upper end of the core catcher body 33 causing the core catcher body to move downwardly with the inner barrel. As the body 33 moves downwardly its lower end bears against the shoulder 42 to move the sleeve 4| downwardly. In this manner the inclined outer surfaces 46 of the slips S are ,forced against the inclined shoulder 30 of the opening 21 so that the slips S are forced inwardly into the core C. After the sleeve 4|.and the core catcher body 33 have moved downwardly a relatively short distance the lower end of the body 33 is disengaged from the shoulder 42 of the inwardly flexed slips S. This allows the core catcher body 33 to move downwardly relative to the sleeve 4| until the lower end of the body 33 engages the shoulders 41. The engagement of the slips S with the shoulder 36 holds the sleeve 4| stationary during this movement or the body 33.

The relative movement between the core catcher body 33 and the sleeve 4| brings the dogs 36 to positions where their springs ,39 pivot them inwardly. through the openings 44. The dogs 36 are thus made to penetrate or bite into the core C and the cam parts 40 may cooperate with the shoulder 28 to further advance or pivot the dogs into the core. The cam parts 40 may engage the walls of the openings to stop or support the dogs in substantially horizontal core supporting positions. Following the release and actuation of the dogs 36 downward movement of the core catcher body 33 may be continued until its lower end engages the shoulder 29. The sleeve 4| is then caused to movedownwardly with the core catcher body 33 sothat its slips S are eflectively forced inwardly togrip the core through the cooperation of the surfaces 46 with the shoulder 30. In most instances the dogs 36 are effective in breaking free and retaining the core. However, the additional engagement of the slips S with the core may aid in removing a hard core. After the inner barrel i3 has moved downwardly as far as it will and the slips 8 have engaged the core, raising of the tool may bring the dogs 36 against the upper ends of the openlugs 44 to increase the actuating or pivoting pressures on the dogs. The engagement of the slips S with the core temporarily holds the ring 4| against movement allowing upward movement of the dogs 36 relative to the ring :to efiect this further actuation of the dogs 36.

Following the tripping and actuation of the core catcher I! the drill is raised and brought to the surface and the core is removed from the inner barrel l3. The core drill of the present invention is particularly effective and is operable to recover full sized unmutilated cores ofearth formations of various characters. The core catcher i2 is normally latched or held'in a fully contracted condition so that it does not cut away the core and may be positively actuated at the will of the operator without manipulation of the drilling string. Accordingly, the drill is operable to remove substantially the entire core from the application herein set forth, but wish to reserve to myself any variations or 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. In a core drill havinga barrel and a core forming cutting head, the combination of a shiftable spring urged core recovering element, a sleeve positioned in the element to hold the element inoperative and adapted to readily pass the core, and spring means for moving the element out of engagement with the sleeve after the pas- 'sage of the core through the element.

2. In a core drill having a barrel and a core forming cutting head, the combination of an annular series of spring urged core recovering elements, a member normally positioned within said series to hold the elements in a retracted position clear of the core, and means for moving the elements out of engagement with the member including a shiftable part normally urged into moving relation with the elements, and a releasable latch in the barrel holding the shiftable part against movement. 3. In a core drill having a barrel and a core forming cutting head, the combination of a spring urged core recovering element at the head,amember at the head normally engaging the element to hold it in a retracted position clear of the core, and means for moving the element out of engagement with the member including a shiftable part normally urged into moving relation with the element, a releasable latch holding the shiftable part against movement, and an object to be passed through the drilling string to release the latch. 4

4. A core drill including a tubular body having cutting means on its lower end, two elements in the body related for relative vertical movement, one a core recovering member, the other a latch part normally holding the member in a retracted position clear of the core, aninner barrel for receiving the core and shiftable to effect relative movement between said elements to release the member for operation, and releasable latch means normally holding the inner barrel against such shifting.

' 5. A core drill including a tubular body having cutting means on its lower end, two relatively movable elements in the body, one a. spring urged core recovering dog, the other a member normally holding the dog in a retracted position, an inner barrel for receiving the core and shiftable to effect relative movement between ,said elements, to release the dog for operation, and releasable latch controlled means normally rotatably suspending the inner barrel and holding it against such movement. v

v6. A core drill including a tubular body having cutting means on its lower end, two, relatively movable elements in the body, one a spring urged core recovering dog, the other a member normally holding the dog in a retracted position, an inner barrel for receiving the core and shiftable to effect relative movement between said elements to release the dog for operation, a spring for shifting the inner barrel, and a latch normally holding the inner barrel against such movement and releasable by an object dropped through the drilling string.

7. A core drill including a tubular body having cutting means at its lower end, a normally inoperative core catcher in the body, an inner barrel in the body for receiving the core and shiftable to actuate the core catcher, a spring for shifting the inner barrel, a longitudinally shiftable member having a rotatable connection with the inner barrel, and a latch holding the member against longitudinal movement and releasable,

by an object passed into the drilling string.

8. A core drill including a tubular body having cutting means at its lower end, a normally inoperative core catcher in the body, an inner barrel in the body for receiving the core and shiftable to actuate the core catcher, a tubular member longitudinally shiftable in the upper portion. of the body and receiving the circulation fluid from the drilling string, there being a port in the member conducting the fluid into the body, a rotatable connection between the inner barrel and member, a latch holding the member against movement to .suspend the inner barrel, and an object adapted to be droppedthrough the drill ing string to release the latch and pass to a position clear ofthe port without interrupting relative to the body and the sleeve to free its dog from the sleeve.

10. A core drill including a tubular body having cutting means at its lower end, a core catcher shiftable in the body and comprising a spring urged core engaging dog, a sleeve in the core catcher normally holding the dog retracted, means normally holding the sleeve against movement, an inner barrel in the body shiftable to move the core catcher to free its dog from'the sleeve,'and means normally holding the inner barrel against shifting releasable under the control of the driller.

11. A core drill including a tubular body having cutting means at its lower end, a core catcher shiftable in the body and comprising a spring urged core engaging dog, a sleeve in'the core catcher normally holding the dog retracted, a core gripping part on the sleeve operable by engagement with the body, yieldable means normally holding the sleeve against movement, and means for shifting the core catcher relative to the sleeve to free the dog from the sleeve and then shifting the sleeve to actuate its gripping part.

12. A core drill including a tubular body having cutting means at its lower end, a core catcher sliiftable in the body and comprising a spring urged core engaging dog, a sleeve in the core catcher normally holding the dog retracted, a core gripping part on the sleeve operable by engagement with the body, yieldable means normally holding the sleeve against movement,

normally spaced movement transmitting shoulders on the core catcher and sleeve, and means for shifting the core catcher to free its dog from the sleeve and then cause movement of the sleeve through cooperation of said shoulders whereby the gripping part is actuated.

13. In a core drill having a tubular body, a shiftable tubular member in the body, pivoted core retaining dogs on the member, springs urging the dogs inwardly, a sleeve within the tubular member normally holding the dogs retracted, the tubular member and sleeve being related for relative movement, there being openings in the sleeve through which the dogs pivot inwardly upon relative movement between the member and sleeve, and means for causing relative movement between the member and sleeve.

14. In a core drill having a tubular body, a shiftable tubular member in the body, pivoted core retaining dogs on the member, springs urging the dogs inwardly, a sleeve within the tubular member normally holding the dogs retracted, the tubular member and sleeve being related for relative movement, there being openings in the sleeve through which the dogs pivot inwardly upon relative movement between the member and sleeve, core gripping slips on the sleeve operable by cooperation With the body, and means for causing relative movement between the member and sleeve and actuating movement of the slips against the body.

15. In a core drill having a tubular body, a shiftable tubular member in the body, pivoted core retaining dogs on the member, springs urging the dogs inwardly, a sleeve within the tubular member normally holding the dogs retracted, the tubular member and sleeve being related for relative movement, there being openings in the sleeve through which the dogs pivot inwardly upon relative movement between the member and sleeve, the sleeve being longitudinally split to be contractible through contact with the body, core gripping parts on the interior of the contractible portion of the sleeve, and means for causing relative movement between the member and sleeve to release the dogs and for moving the sleeve to contract the same.

16. In a core drill having a tubular body, a shiftable tubular member in the body, pivoted spring urged dogs on the member, a sleeve. in the member having both ends open to receive the core and normally holding the dogs retracted, and means limiting movement of the sleeve whereby it passes downwardly over the core as the same is formed.

ALFRED C. CATLAND.