Coring tool

• US 4,930,587 A
• Filed: 08/28/1989
• Issued: 06/05/1990
• Est. Priority Date: 04/25/1989
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Diamant Boart Stratabit Incorporated (AB Electrolux)
• Inventors: Young, David E., Easton, Andrew R., Koskie, Earl T. Jr.
• Primary Examiner(s): Neuder, William P.
• Application Number:
  US07/400,132
• Time in Patent Office: 281 Days
• Field of Search: 175/58, 175/249, 175/251, 175/253, 175/254
• US Class Current: 175/251
• CPC Class Codes: E21B 25/14 mounted on pivot transverse to core axis

Abstract

A coring tool comprises a core cutting section and an actuating section disposed thereabove. The core cutting section includes axially telescoping outer and inner barrels. The inner barrel includes a jaw carrier which carries pivotable core-catching jaws normally covered along their radially inner sides by a driver sleeve. When the driver sleeve is raised by the actuator section the jaws are uncovered. Thereafter, the driver sleeve raises the jaw carrier to bring the jaws into contact with a stationary inclined jaw-deflecting surface to force the jaws laterally inwardly through the core. The actuator section relies upon fluid pressure to release for movement a vertically risible member which is mechanically lifted by a drill string to transmit vertical forces to the driver sleeve from a drill string.

Claims

1. A coring tool adapted to be mounted at a lower end of a drill string for cutting and catching a subterranean core, comprising:

outer barrel means including a hollow drill bit disposed at a lower end of said barrel means and adapted to be rotated about a vertical longitudinal axis for cutting a core, and

inner barrel means disposed coaxially within said outer barrel means and including jaw carrier means, driver sleeve means disposed coaxially within said jaw carrier means, and jaw closing means disposed laterally between said jaw carrier means and said driver sleeve means,

said jaw carrier means mounted for longitudinal displacement relative to said outer barrel means and including a downwardly facing stop surface, and jaw means arranged to be laterally inwardly displaced from a rest position to a core catching position,

said jaw closing means disposed above and in a longitudinal path of travel of said jaw means,

said jaw carrier means arranged to be upwardly displaceable relative to said jaw closing means in response to upward movement of said jaw carrier means relative to said outer barrel,

said driver sleeve extending radially inwardly of, and downwardly past, said jaw means to radially cover said jaw means during a core cutting operation and including an upwardly facing abutment face, said driver sleeve being arranged to be upwardly displaced relative to both said jaw carrier means and said jaw-closing means in response to the application of upward force to said driver sleeve by a drill string to radially uncover said jaw means and bring said abutment face into engagement with said stop surface to displace said jaw carrier means upwardly relatively to said outer barrel such that said jaw means is raised into contact with said jaw closing means and is subjected to a deflecting force therefrom which deflects said jaw means from said rest position to said core-catching position, said jaw-closing means being operably connected to said outer barrel means such that the weight of said outer barrel means is applied downwardly against said jaw means through said jaw-closing means.

2. A coring tool according to claim 1, wherein said jaw means comprises a plurality of closure jaws pivotably connected at their lower ends to said jaw carrier means.

3. A coring tool according to claim 1, wherein said jaw-closing means comprises a closure sleeve having an inclined lower surface against which said jaw means abuts.

4. A coring tool according to claim 1, including a bearing ring disposed coaxially with and radially between said jaw-carrier means and said outer barrel means at an elevation above said jaw means, said bearing ring being operably connected to said jaw-closing means by means of radial key passing through longitudinally elongated slots in said jaw-carrying means, said bearing ring carrying bearing means permitting said outer barrel means to rotate relative to said inner barrel means.

5. A coring tool according to claim 4, wherein said bearing ring is arranged to transmit upward forces from said jaw closing sleeve to said outer barrel means.

6. A coring tool according to claim 1, wherein said outer and inner barrel means define a core catching section of said tool, said tool including an actuating section disposed above said core-catching section, said outer barrel means being connected to said actuating section such that a portion of the weight of said actuating section is applied against said jaw means.

7. A coring tool according to claim 6, wherein said actuating section comprises an outer sleeve assembly and an inner sleeve assembly disposed coaxially within said outer sleeve assembly and defining a longitudinal fluid passage, said outer sleeve assembly being operably connected to said outer barrel means for transmitting rotary forces thereto, said inner sleeve assembly being operably connected to said driver sleeve for transmitting vertical forces thereto from the drill string, a plurality of radial dogs extending radially between said inner and outer sleeve assemblies and being radially movable between a radially outward locking position preventing upward movement of said inner sleeve assembly relative to said outer sleeve assembly and a radially inward unlocking position permitting said inner sleeve assembly to move upwardly relative to said outer sleeve assembly, said inner sleeve assembly including a dog release member disposed coaxially within said fluid passage, said dog release member including a surface blocking movement of said dogs from said locking position to said unlocking position, said dog release member including a plurality of flexible fingers latched to a shoulder of said inner sleeve assembly to prevent downward movement of said dog release member, said dog release member including a longitudinal fluid port having an upwardly facing seat adapted to receive a plug dropped from the ground surface for blocking said port until fluid pressure moves said dog release member downwardly to unblock said dogs.

8. A coring tool adapted to be mounted at a lower end of a drill string for cutting and catching a subterranean core, comprising:

outer barrel means including a hollow drill bit disposed at a lower end of said barrel means and adapted to be rotated about a vertical longitudinal axis for cutting a core, and

inner barrel means disposed coaxially within said outer barrel means and including;

a jaw-carrier sleeve mounted for longitudinal displacement relative to said outer barrel means and including a downwardly facing stop surface, and a pair of pivotably mounted jaws arranged to be swung laterally inwardly from a rest position to a core catching position,

a jaw closing sleeve having an upwardly and inwardly inclined lower surface arranged above and in a longitudinal path of travel of said jaws,

said jaw carrier sleeve arranged to be upwardly displaceable relative to said jaw closing sleeve,

a bearing ring disposed coaxially with and radially between said jaw-carrier sleeve and said outer barrel means at an elevation above said jaws, said bearing ring being operably connected to said jaw closing sleeve by means of radial keys passing through longitudinally elongate slots in said jaw-carrying sleeve, said bearing ring carrying bearing means permitting said outer barrel means to rotate relative to said inner barrel means,

a driver sleeve disposed coaxially within said jaw carrying sleeve and extending downwardly past said jaws to radially cover said jaws during a core cutting operation and including an upwardly facing abutment face, said driver sleeve being arranged to be upwardly displaced relative to both said jaw carrying sleeve and said jaw-closing sleeve in response to the application of upward forces to said driver sleeve by a drill string to radially uncover said jaws and bring said abutment face into engagement with said stop surface to displace said jaw carrying sleeve upwardly such that said jaws are raised into contact with said inclined lower surface of said jaw closing sleeve and are subjected to a deflecting force therefrom which deflects said jaws from said rest position to said core-catching position,

said jaw closing sleeve being operably connected to said outer barrel means through said bearing ring such that the weight of said outer barrel means is applied downwardly against said jaws through said jaw closing sleeve.

9. In a tool insertable into a well bore and including a lower section and an actuating section disposed above said lower section,

said lower section including coaxially telescoping outer and inner portions, said inner portion being movable vertically relative to said outer portion,

said actuating section disposed above said lower section and including an outer sleeve assembly operably connected to said outer portion, and an inner sleeve assembly disposed coaxially within said outer sleeve assembly and being operably connected to said inner portion for transmitting vertical forces thereto, said inner sleeve assembly defining a longitudinal fluid passage, and comprising:

a tubular portion containing a plurality of radial slots and shoulder surface means extending at an acute angle relative to a longitudinal axis of said tubular portion,

a plurality of radial dogs disposed in said slots and extending radially between said inner and outer sleeve assemblies and being radially movable between a radially outward locking position preventing upward movement of said inner sleeve assembly relative to said outer sleeve assembly and a radially inward unlocking position permitting said inner sleeve assembly to move upwardly relative to said outer sleeve assembly, and

a dog release member disposed within said fluid passage and including;

a surface arranged for blocking movement of said dogs from said locking position to said unlocking position,

a plurality of flexible fingers each including a hook surface extending at an acute angle relative to said longitudinal axis and engaging said shoulder surface means to prevent downward movement of said dog release member, and

a longitudinal fluid port having an upwardly facing seat adapted to receive a plug dropped from the ground surface for blocking said port until fluid pressure is sufficient to displace said hook surfaces from said shoulder surface means and move said dog release member downwardly to unblock said dogs and permit said dogs to be cammed radially inwardly in response to vertical movement of said inner sleeve assembly relative to said outer sleeve assembly.

10. A tool according to claim 9, wherein said tool comprises a coring tool, said outer portion comprising outer barrel means with a hollow drill bit for cutting a core, and said inner portion comprising inner barrel means carrying a core catcher for catching the core.

11. A tool according to claim 9, wherein said outer sleeve assembly includes a radially inwardly facing groove, said inner sleeve assembly carrying a snap ring which snaps into said groove after said dogs have been moved to their unlocking position and said inner sleeve assembly has moved upwardly relative to said outer sleeve assembly, whereby said snap ring locks said inner and outer sleeve assemblies together.