# Patent

## Title
Driven latch mechanism

## Abstract

A core barrel assembly having a driven latch mechanism that can lock the core barrel assembly axially and rotationally relative to a drill string. The driven latch mechanism can include a plurality of wedge members positioned on a plurality of driving surfaces. Rotation of the drill string can cause the plurality of wedge members to wedge between an inner diameter of the drill string and the plurality of driving surfaces, thereby rotationally locking the core barrel assembly relative to the drill string. Drilling systems including the driven latch mechanism and methods of using the driven latch mechanism are also described.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of U.S. Provisional Application No. 61/249,544, filed Oct. 7, 2009, entitled “Driven Latch Mechanism.” This application also claims priority to and the benefit of U.S. Provisional Application No. 61/287,106, filed Dec. 16, 2009, entitled “Driven Latch Mechanism for High Productivity Core Drilling.” The contents of the above-referenced patent application are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
1. The Field of the Invention
Implementations of the present invention relate generally to drilling devices and methods that may be used to drill geological and/or manmade formations. In particular, implementations of the present invention relate to core barrel assemblies and to mechanisms for latching core barrel assemblies to a drill string.
2. The Relevant Technology
Exploration drilling can include retrieving a sample of a desired material (core sample) from a formation. Wireline drilling systems are one common type of drilling system for retrieving a core sample. In wireline drilling process, a core drill bit is attached to the leading edge of an outer tube or drill rod. A drill string is then formed by attaching a series of drill rods that are assembled together section by section as the outer tube is lowered deeper into the desired formation. A core barrel assembly is then lowered or pumped into the drill string. The core drill bit is rotated, pushed, and/or vibrated into the formation, thereby causing a sample of the desired material to enter into the core barrel assembly. Once the core sample is obtained, the core barrel assembly is retrieved from the drill string using a wireline. The core sample can then be removed from the core barrel assembly.
Core barrel assemblies commonly include a core barrel for receiving the core, and a head assembly for attaching to the wireline. Typically, the core barrel assembly is lowered into the drill string until the core barrel reaches a portion the outer tube or distal most drill rod. At this point a latch on the head assembly is deployed to restrict the movement of the core barrel assembly with respect to the drill rod. Once latched, the core barrel assembly is then advanced into the formation along with the drill rod, causing material to fill the core barrel.
One potential challenge can arise due to the interaction between the core barrel assembly and the drill string. For example, when the drill string is spinning, the inertia of the core barrel assembly can exceed the frictional resistance between the mating components such that the head assembly rotates at a lower rate than the drill rod or fails to rotate and remains stationary. In such a situation, the mating components can suffer sliding contact, which can result in abrasive wear.
Accordingly, there are a number of disadvantages in conventional wireline systems that can be addressed.
BRIEF SUMMARY OF THE INVENTION
One or more implementations of the present invention overcome one or more problems in the art with drilling tools, systems, and methods for effectively and efficiently latching a core barrel assembly to a drill string. For example, one or more implementations of the present invention include a core barrel assembly having a driven latch mechanism that can reliably lock the core barrel assembly in a fixed axial position within a drill string. Additionally, the drive latch mechanism can reduce or eliminate wear between mating components of the core barrel assembly and the drill string. In particular, the driven latch mechanism can rotationally lock the core barrel assembly relative to the drill string, thereby reducing or eliminating sliding contact (and associated wear) between mating components of the core barrel assembly and the drill string.
For example, one implementation of a core barrel head assembly includes a sleeve having a plurality of latch openings extending there through. The core barrel head assembly can also include a driving member positioned at least partially within the sleeve. The driving member can include a plurality of planar driving surfaces. Additionally, the core barrel head assembly can include a plurality of wedge members positioned on or against the plurality of planar driving surfaces. The plurality of wedge members can extend within the plurality of latch openings. The driving member can wedge the plurality of wedge members between an inner surface of the drill string and the plurality of planar driving surfaces, thereby preventing rotation of the core barrel head assembly relative to the drill string.
Additionally, another implementation of a core barrel head assembly can include a sleeve, a latch body moveably coupled to the sleeve, and a driving member positioned at least partially within the sleeve. The core barrel head assembly can also include a landing member positioned at least partially within the latch body. Further, the core barrel head assembly can include a plurality of wedge members positioned on the driving member. Axial movement of the driving member relative to the plurality of wedge members can move the plurality of wedge members radially relative to the sleeve between a latched position and a released position. Still further the core barrel head assembly can include a plurality of braking elements positioned on the landing member. Axial movement of the landing member relative to the plurality of braking elements can move the plurality of braking elements radially relative to the latch body between a retracted position and an extended position.
Furthermore, an implementation of a drilling system for retrieving a core sample can include a drill rod including a first annular recess extending into an inner diameter of the drill rod. Also, the drilling system can include a core barrel assembly adapted to be inserted within the drill rod. Additionally, the drilling system can include a driven latch mechanism positioned within the core barrel assembly. The driven latch mechanism can include a driving member including a plurality of planar driving surfaces, and a plurality of wedge members. Axial displacement of the driving member relative to the plurality of wedge members can push or force the plurality of wedge into the first annular recess of the drill rod, thereby axially locking the core barrel head assembly relative to the drill rod. Furthermore, rotation of the drill rod can cause the plurality of wedge members to rotationally lock the core barrel assembly relative to the drill rod.
In addition to the foregoing, a method of drilling can involve inserting a core barrel assembly within a drill string. The core barrel assembly can comprise a driven latch mechanism including a plurality of wedge members positioned on a plurality of planar driving surfaces. The method can further involve moving the core barrel assembly within the drill string to a drilling position. The method can also involve deploying the plurality of wedge members into an annular groove of the drill string. Additionally, the method can involve rotating the drill string thereby causing the plurality of wedge members to wedge between the inner diameter of the drill string and the plurality of planar driving surfaces. The wedging of the plurality of wedge members can rotationally lock the core barrel assembly relative to the drill string.
Additional features and advantages of exemplary implementations of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of such exemplary implementations. The features and advantages of such implementations may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter.



BRIEF DESCRIPTION OF THE DRAWINGS
In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It should be noted that the figures are not drawn to scale, and that elements of similar structure or function are generally represented by like reference numerals for illustrative purposes throughout the figures. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 illustrates a schematic view a drilling system including a core barrel assembly having a driven latch mechanism in accordance with an implementation of the present invention;
FIG. 2 illustrates an enlarged view of the core barrel assembly of FIG. 1, further illustrating a head assembly and a core barrel;
FIG. 3 illustrates an exploded view of the head assembly of FIG. 2;
FIG. 4 illustrates a cross-sectional view of the core barrel assembly of FIG. 2 taken along the line 4-4 of FIG. 2;
FIG. 5 illustrates a cross-sectional view of the core barrel assembly of FIG. 2 similar to FIG. 4, albeit with the driven latch mechanism in position for pumping the core barrel assembly within a drill string;
FIG. 6A illustrates a cross-sectional view of the core barely assembly of FIG. 5 taken along the line 6-6 of FIG. 5 in which a braking mechanism engages a drill rod having a first inner diameter;
FIG. 6B illustrates a cross-sectional view of the core barely assembly of FIG. 5 similar to FIG. 6A, albeit with the braking mechanism engaging a drill rod having a diameter larger than the first diameter;
FIG. 7 illustrates a cross-sectional view of the core barrel assembly similar to FIG. 4, albeit with the driven latch mechanism latched to the drill string;
FIG. 8 illustrates a cross-sectional view of the core barrel assembly of FIG. 7 taken along the line 8-8 of FIG. 7; and
FIG. 9 illustrates a cross-sectional view of the core barrel assembly similar to FIG. 4, albeit with the driven latch mechanism in a released position allowing for retrieval of the core barrel assembly from the drill string.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Implementations of the present invention are directed toward drilling tools, systems, and methods for effectively and efficiently latching a core barrel assembly to a drill string. For example, one or more implementations of the present invention include a core barrel assembly having a driven latch mechanism that can reliably lock the core barrel assembly in a fixed axial position within a drill string. Additionally, the drive latch mechanism can reduce or eliminate wear between mating components of the core barrel assembly and the drill string. In particular, the driven latch mechanism can rotationally lock the core barrel assembly relative to the drill string, thereby reducing or eliminating sliding contact (and associated wear) between mating components of the core barrel assembly and the drill string.
Assemblies, systems, and methods of one or more implementations can include or make use of a driven latch mechanism for securing a core barrel assembly at a desired position within a tubular member, such as a drill rod of a drill string. The driven latch mechanism can include a plurality of wedge members, and a driving member having a plurality of driving surfaces. The driving surfaces drive the wedge members to interact with an inner surface of a drill rod to latch or lock the core barrel assembly in a desired position within the drill string. Thereafter, rotation of the drill rod can cause the wedge members to wedge between the drive surfaces and the inner diameter of the drill rod, thereby rotationally locking the core barrel relative to the drill string.
Furthermore, one or more implementations provide a driven latch mechanism that can maintain a deployed or latched condition despite vibration and inertial loading of mating head assembly components due to drilling operations or abnormal drill string movement. Also, one or more implementations can provide a latch mechanism that does not disengage or retract unintentionally, and thus prevents the core barrel inner tube assembly from rising from the drilling position in a down-angled hole, or falling unannounced from an up-angled drill hole.
Additionally, one or more implementations can include a braking mechanism that can prevent the core barrel assembly from unintentionally sliding out of the drill string in an uncontrolled and possibly unsafe manner. In particular, the braking mechanism can include a landing member and a plurality of brake elements. The landing member can push the plurality of brake elements against an inner surface of a drill string, allowing the braking mechanism to stop axial movement of the core barrel assembly within or relative to the drill string. In one or more implementations, the landing member can include a taper such that varying the axial position of the landing member varies the radial position of the brake elements, thereby allowing the brake elements to maintain engagement with a variable inner diameter of a drill string.
For ease of reference, the driven latch mechanism shall be described with generally planar driving surfaces and spherical or ball-shaped wedge members. It will be appreciated that the driving members can have any number of driving surfaces with any desired shape, including, but not limited to, convex, concave, patterned or any other shape or configuration capable of wedging a wedge member as desired. Further, the wedge members can have any shape and configuration possible. In at least one example, a universal-type joint can replace the generally spherical wedge members, tapered planar drive surfaces, and accompanying sockets. Thus, the present invention can be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
In other words, the following description supplies specific details in order to provide a thorough understanding of the invention. Nevertheless, the skilled artisan would understand that the apparatus and associated methods of using the apparatus can be implemented and used without employing these specific details. Indeed, the apparatus and associated methods can be placed into practice by modifying the illustrated apparatus and associated methods and can be used in conjunction with any other apparatus and techniques. For example, while the description below focuses on core sample operations, the apparatus and associated methods could be equally applied in other drilling processes, such as in conventional borehole drilling, and may be used with any number or varieties of drilling systems, such as rotary drill systems, percussive drill systems, etc.
Further, while the Figures show six wedge members in the latching mechanism, any number of latches may be used. In at least one example, five ball-shaped wedge members will be used in a driven latch mechanism. Similarly, the precise configuration of components as illustrated may be modified or rearranged as desired by one of ordinary skill. Additionally, while the illustrated implementations specifically discuss a wireline system, any retrieval system may be used, such as a drill string.
As shown in FIG. 1, a drilling system 100 may be used to retrieve a core sample from a formation 102. The drilling system 100 may include a drill string 104 that may include a drill bit 106 (for example, an open-faced drill bit or other type of drill bit) and/or one or more drill rods 108. The drilling system 100 may also include an in-hole assembly, such as a core barrel assembly 110. The core barrel assembly 110 can include a driven latch mechanism configured to lock the core barrel assembly at least partially within a distal drill rod or outer tube 112, as explained in greater detail below. As used herein the terms “down” and “distal end” refer to the end of the drill string 104 including the drill bit 106, whether the drill string be oriented horizontally, at an upward angle, or a downward angle relative to the horizontal. While the terms “up” or “proximal” refer to the end of the drill string 104 opposite the drill bit 106.
The drilling system 100 may include a drill rig 114 that may rotate and/or push the drill bit 106, the core barrel assembly 110, the drill rods 108 and/or other portions of the drill string 104 into the formation 102. The drill rig 114 may include, for example, a rotary drill head 116, a sled assembly 118, a slide frame 120 and/or a drive assembly 122. The drill head 116 may be coupled to the drill string 104, and can allow the rotary drill head 116 to rotate the drill bit 106, the core barrel assembly 110, the drill rods 108 and/or other portions of the drill string 104. If desired, the rotary drill head 116 may be configured to vary the speed and/or direction that it rotates these components. The drive assembly 122 may be configured to move the sled assembly 118 relative to the slide frame 120. As the sled assembly 118 moves relative to the slide frame 120, the sled assembly 118 may provide a force against the rotary drill head 116, which may push the drill bit 106, the core barrel assembly 110, the drill rods 108 and/or other portions of the drill string 104 further into the formation 102, for example, while they are being rotated.
It will be appreciated, however, that the drill rig 114 does not require a rotary drill head, a sled assembly, a slide frame or a drive assembly and that the drill rig 114 may include other suitable components. It will also be appreciated that the drilling system 100 does not require a drill rig and that the drilling system 100 may include other suitable components that may rotate and/or push the drill bit 106, the core barrel assembly 110, the drill rods 108 and/or other portions of the drill string 104 into the formation 102. For example, sonic, percussive, or down hole motors may be used.
The core barrel assembly 110 may include an inner tube or core barrel 124, and a head assembly 126. The head assembly 126 can include a driven latch mechanism 128. As explained in greater detail below, the driven latch mechanism 128 can lock the core barrel 124 within the drill string 104, and particularly to the outer tube 112. Furthermore, the driven latch mechanism 128 can rotationally lock the core barrel assembly 110 to the drill string 104 thereby preventing wear due to rotation or sliding between the mating components of the driven latch mechanism 128 and the drill string 104.
Once the core barrel 124 is locked to the outer tube 112 via the driven latch mechanism 128, the drill bit 106, the core barrel assembly 110, the drill rods 108 and/or other portions of the drill string 104 may be rotated and/or pushed into the formation 102 to allow a core sample to be collected within the core barrel 124. After the core sample is collected, the core barrel assembly 110 may be unlocked from the outer tube 112 and drill string 104. The core barrel assembly 110 may then be retrieved, for instance using a wireline retrieval system, while the drill bit 106, the outer tube 112, one or more of the drill rods 108 and/or other portions of the drill string 104 remain within the borehole.
The core sample may be removed from core barrel 124 of the retrieved core barrel assembly 110. After the core sample is removed, the core barrel assembly 110 may be sent back and locked to the outer tube 112. With the core barrel assembly 110 once again locked to the outer tube 112, the drill bit 106, the core barrel assembly 110, the drill rods 108 and/or other portions of the drill string 104 may be rotated and/or pushed further into the formation 102 to allow another core sample to be collected within the core barrel 124. The core barrel assembly 110 may be repeatedly retrieved and sent back in this manner to obtain several core samples, while the drill bit 106, the outer tube 112, one or more of the drill rods 108 and/or other portions of the drill string 104 remain within the borehole. This may advantageously reduce the time necessary to obtain core samples because the drill string 104 need not be tripped out of the borehole for each core sample.
During some drilling processes, hydraulic pressure may be used to pump and/or advance core barrel assembly 110 within the drill string 104 to the outer tube 112. In particular, hydraulic pressure may be used to pump the core barrel assembly 110 within the drill string 104 to the outer tube 112 when the drill string 104 is oriented upwardly relative to the horizontal (as shown in FIG. 1), is oriented generally horizontally, or oriented with a slight downward angle relative to the horizontal. To allow for the core barrel assembly 110 to be pumped to the outer tube 112, the core barrel assembly 110 can further include a seal 130 configured to form a seal with one or more portions of the drill string 104, such as, inner walls of the drill rods 108. The seal 130 may be further configured as a pump-in seal, such that pressurized fluid pumped into the drill string 104 behind the seal 130 may cause hydraulic pressure behind the seal 130 to pump and/or advance the core barrel assembly 110 within and along the drill string 104 until the core barrel assembly 110 reaches a desired position (for instance, a position at which the core barrel assembly 110 can be connected to the outer tube 112 as discussed above).
In one or more implementations, the core barrel assembly 110 can further include a braking mechanism 132. The braking mechanism 132 can help prevent unintended expulsion of the core barrel assembly 110 from the drill string 104. Thus, the braking mechanism 132 can allow wireline retrieval systems to be used in up-hole drilling operations without the danger of the core barrel assembly 110 sliding out of the drill string 104 in an uncontrolled and possibly unsafe manner. Accordingly, the braking mechanism 132 can resist unintended removal or expulsion of the core barrel assembly 110 from the borehole by deploying the braking elements into a frictional arrangement between an inner wall of the casing or drill string 104 (or borehole).
FIG. 2 illustrates the core barrel assembly 110 in greater detail. As previously mentioned, the core barrel assembly 110 can include a head assembly 126 and a core barrel 124. The head assembly 126 can include a spear head assembly 200 adapted to couple with an overshot, which in turn can be attached to a wireline. Furthermore, the head assembly 126 can include a first member 202 that can house the braking mechanism 132, and a sleeve 204 that can house the driven latch mechanism 128.
FIGS. 3 and 4 and the corresponding text, illustrate or describe a number of components, details, and features of the core barrel assembly 110 shown in FIGS. 1 and 2. In particular, FIG. 3 illustrates an exploded view of the head assembly 126. While FIG. 4 illustrates a side, cross-sectional view of the core barrel assembly 110 taken along the line 4-4 of FIG. 2. FIG. 4 illustrates the driven latch mechanism 128 and the braking mechanism 132 in a fully deployed state. As shown by FIGS. 3 and 4, the driven latch mechanism 128 can include a plurality of wedge members 300. In one or more implementations, the wedge members 300 can comprise a spherical shape or be roller balls, as shown in FIGS. 3 and 4. The wedge members 300 may be made of steel, or other iron alloys, titanium and titanium alloys, compounds using aramid fibers, lubrication impregnated nylons or plastics, combinations thereof, or other suitable materials.
The wedge members 300 can be positioned on or against a driving member 302. More particularly, the wedge members 300 can be positioned on generally planar or flat driving surfaces 304. As explained in greater detail below, the generally planar configuration of the driving surfaces 304 can allow the wedge members 300 to be wedged between the driving member 302 and the inner diameter of a drill string to rotationally lock the core barrel assembly 110 to the drill string.
FIGS. 3 and 4 further illustrate that the wedge members 300 can extend through latch openings 306 extending through the generally hollow sleeve 204. The latch openings 306 can help hold or maintain the wedge members 300 in contact with the driving surfaces 304, which in turn can ensure that axial movement of the driving member 302 relative to the sleeve 204 results in radial displacement of the wedge members 300. As explained in greater detail below, as the driving member 302 moves axially toward or farther into the sleeve 204, the driving surfaces 304 can force the wedge members 300 radially outward of the sleeve 204 to a deployed or latched position (FIG. 7). Along similar lines, as the driving member 302 moves axially away from, or out of the sleeve 204, the wedge members 300 can radially retract at least partially into the sleeve 204 into a released position (FIG. 5).
In one or more implementations, the driving member 302, and more particularly the planar driving surfaces 304 can have a taper, as shown in FIGS. 3 and 4. The taper can allow the driving member 302 to force the wedge balls 300 radially outward as the driving member 302 moves axially closer to, or within, the sleeve 204. Also, the taper of the driving member 302 can allow the wedge members 300 to radially retract at least partially into the sleeve 204 when the driving member 302 moves axially away from the sleeve 204. One will appreciate that the driving member 302 (and driving surfaces 304) need not be tapered. For example, in alternative implementations, the driving member 302 can include a first portion have a smaller diameter, a transition portion, and a second portion with a larger diameter. In other words, the driving member 302 can include a step between a smaller diameter and a larger diameter instead of a taper along its length. The smaller diameter portion of the driving member 302 of such implementations can allow the wedge balls 300 to retract at least partially into the sleeve 204, and the larger diameter of the driving member 302 can force the wedge balls 300 radially outward in order to lock or latch to the drill string.
FIGS. 3 and 4 further illustrate that in addition to the driving member 302, the first member 202 can include a latch body 308. The latch body 308 can be generally hollow and can house the braking mechanism 132. As shown by FIGS. 3 and 4, the braking mechanism 132 can include a plurality of braking elements 310. In one or more implementations, the braking elements 310 can comprise a spherical shape or be roller balls, as shown in FIGS. 3 and 4. In other examples, the braking elements 310 may be flat, may have a cylindrical shape, or may have a wedge shape, to increase the braking surface area of the braking elements 310 against a casing and/or a conical surface. In other embodiments, the braking elements 310 may be of any shape and design desired to accomplish any desired braking characteristics.
The braking elements 310 may be made of any material suitable for being used as a compressive friction braking element. For example, the braking elements 310 may be made of steel, or other iron alloys, titanium and titanium alloys, compounds using aramid fibers, lubrication impregnated nylons or plastics, or combinations thereof. The material used for any braking element 310 can be the same or different than any other braking element 310.
The braking elements 310 can be positioned on a landing member 312. More particularly, the braking elements 310 can be positioned on generally conical or tapered landing member 312. As explained in greater detail below, the generally conical or tapered shape of the landing member 312 can allow the braking elements 310 to engage or maintain contact with an inner diameter of a drill rod that varies along its length. For example, some drill rods or casing have a first smaller inner diameter at their ends (near couplings) and a larger inner diameter near the their center. The larger inner diameter can allow for increase fluid flow around a core barrel assembly, and thus, faster tripping in and tripping out of a core barrel assembly. The tapered or conical configuration of the landing member 312 can allow axial translation of the landing member 312 to result in radial displacement of the braking elements 310, which in turn allow the braking elements 310 to move in and out of contact with the inner surface of an associated drill rod to prevent unintended or unwanted expulsion, as will be discussed in more detail below.
FIGS. 3 and 4 further illustrate that the braking elements 310 can extend through brake openings 314 extending through the generally first member 308. The brake openings 314 can help hold or maintain the braking elements 310 in contact with the tapered surface of the landing member 312, which in turn can ensure that axial movement of the landing member 312 relative to the latch body 308 results in radial displacement of the braking elements 310. As explained in greater detail below, as the landing member 312 moves axially out of or away from the latch body 308, the tapered surface(s) of the landing member 312 can force the braking elements 310 radially outward of the latch body 308 to an extended position. Along similar lines, as the landing member 312 moves axially toward or farther into the latch body 308, the braking elements 310 can radially retract at least partially into the latch body 308 into a retracted position.
One will appreciate that the sleeve 204, first member 202, and landing member 312 can all be coupled together. In particular, as shown by FIGS. 3 and 4, in at least one implementation a first pin 320 can extend through a mounting channel 322 in the landing member 312. The first pin 320 can then extend through mounting slots 324 of the first member 202 (and more particularly the driving member 302). From the mounting slots 324, the first pin 320 can extend into mounting holes 326 in the sleeve 204. Thus, the landing member 312 and the sleeve 204 can be axially fixed relative to each other. On the other hand, the mounting slots 324 can allow the landing member 312 and the sleeve 204 to move axially relative to the first member 202 or vice versa. Axial movement between the first member 202 and the sleeve 204 can cause the driving surfaces 304 to move the wedge members 300 radially outward and inward. While axial movement between the landing member 312 and the first member 202 can cause the landing member 312 to move the braking elements 310 radially outward and inward.
FIGS. 3 and 4 further illustrate that the head assembly 126 can include a biasing member 330. The biasing member 330 can bias the landing member 312 axially away from the driving member 302. The biasing of the landing member 312 away from the driving member 302 can tend to force the landing member 312 against the braking elements 310, thereby biasing the braking elements 310 radially outward. Similarly, in one or more implementations, the biasing member 330 can bias the driving member 302 against the wedge members 300, thereby biasing the wedge members 300 radially outward. The biasing member 330 can comprise a mechanical (e.g., spring), magnetic, or other mechanism configured to bias the landing member 312 axially away from the driving member 302. For example, FIGS. 3 and 4 illustrate that the biasing member 330 can comprise a coil spring.
The head assembly 126 can further include a brake head 340. The brake head 340 can be coupled to the landing member 312. In one or more implementations, the brake head 340 can comprise a stop configured to prevent the brake elements 310 from leaving the tapered surface of the landing member 312.
Still further, FIGS. 3 and 4 illustrate that the head assembly 126 can include a fluid control member 342. The fluid control member 342 can include a piston 344 and a shaft 345. The shaft 345 can include a channel 346 defined therein. A piston pin 348 can extend within the channel 346 and be coupled to pin holes 350 within the first member 202 (and particularly the driving member 302). The channel 346 can thus allow the piston 344 to move axially relative to the driving member 302. In particular, as explained in greater detail below, piston can move axially relative to the first member 202 in and out of engagement with a seal or bushing 352 forming a valve. The interaction of the fluid control member 342 will be discussed in more detail hereinafter.
In conjunction with the fluid control member 342 and seal 130, the core barrel assembly 110 can include various additional features to aid in pumping the core barrel assembly 110 down a drill string 104. In particular, the sleeve 204 can include one or more fluid ports 370 extending through the sleeve 204. Additionally, the sleeve 204 can include one or more axial grooves 372 extending at least partially along the length thereof. Similarly, first member 202 can include one or more fluid ports 376 extending through the first member 202. Furthermore, the first member 202 can include one or more axial grooves 378 extending at least partially along the length thereof.
One will appreciate in light of the disclosure herein that the fluid ports 372, 376 can allow fluid to flow from the outside diameter of the head assembly 126 into the center or bore of the head assembly 126. The axial grooves 378 on the other hand can allow fluid to flow axially along the head assembly 126 between the outer diameter of the head assembly 126 and the inner diameter of a drill string 104. In addition to the fluid ports and axial grooves, the core barrel assembly 110 can include a central bore 380 that can allow fluid to flow internally through the core barrel assembly 110, past the seals 130.
As previously mentioned, the head assembly 126 can include a spearhead assembly 200. The spear head assembly 200 can be coupled to the first member 202 via a spearhead pin 360. The spearhead pin 360 can extend within a mounting channel 362 in the spearhead assembly 200, thereby allowing the spearhead assembly 200 to move axially relative to the first member 202.
Referring now to FIGS. 5-9 operation of the core barrel assembly 110, driven latch mechanism 128, and braking mechanism 132 will now be described in greater detail. As previously mentioned, in one or more implementations of the present invention the core barrel assembly 110 can be pumped into a drill string 104 using hydraulic pressure. For example, FIG. 5 illustrates the core barrel assembly 110 as it is tripped into or down a drill string 104.
Specifically, FIG. 5 illustrates that the piston 344 is positioned against the bushing 352, thereby sealing off the central bore 380. Furthermore, the seal 130 seals the core barrel assembly 110 to the drill string 104. Thus, in the pump-in configuration shown by FIG. 5, fluid cannot pass through past the bushing 352 and piston 344 through the central bore 380 or past the seal 130 between in an annulus between the core drill barrel assembly 110 and the inner diameter 502 of the drill string 104. As such, as fluid is pumped into the drill string 344, the hydraulic pressure acts on the core barrel assembly 110 (piston 344 etc.) and pushes the core barrel assembly 110 down the drill string 104.
As the core barrel assembly 110 is pumped down the drill string 104, the pump-in force can act on the piston 344, causing the proximal end of the piston channel 346 to engage the piston pin 344. Thus, the pump in force can exert a distally directed force on the piston 344 and the first member 202 (as the first member 202 is secured to the piston pin 348). At the first member 202 is pushed distally by the pump in force, it can cause the braking elements 310 to ride distally along the tapered surface of the landing member 312. This is at least in part because the biasing member 330 exerts a proximal force on the landing member 312. The axial movement of the braking elements 310 (in the distal direction) relative to the tapered surface of the landing member 312 can force the braking elements radially outward until the braking elements 310 ride on the inner diameter 502 of the drill string 104 as shown by FIG. 5. Thus, the biasing member 330 can help retain the braking elements 310 in an extended position as the core barrel assembly 110 is pumped down the drill string 104.
With the braking elements 310 riding on the inner diameter 502 of the drill string 104, any further distal movement of the braking elements 310, piston pin 348, and piston 344 relative to the landing member 312 and sleeve 204 can be prevented. Thus, the piston 344 can be prevented from being pushed through the bushing 352 by the pump in force. Additionally, the driving member 302 can be prevented from moving axially in the distal direction relative to the sleeve 204, which can retain in a radially retracted portion. Maintaining the wedge members 300 at least partially retracted within the sleeve 204 can reduce friction between the drill string 104 and the latch mechanism 128, thereby increasing the speed with which the core barrel assembly 110 can be tripped down the drill string 104.
One will appreciate in light of the disclosure herein that the braking mechanism 132 can help prevent unintentional proximal movement of the core barrel assembly 110. For example, if proximal force were to act on the core barrel assembly 110 (such as gravity overcoming the pump in force due to a hydraulic problem), the landing member 312 can be urged proximally relative the braking elements 310 thereby forcing the braking elements 310 radially outward against the drill string 104 and braking or stopping proximal movement of the core barrel assembly 110. Thus, the braking mechanism 132 can act as a safety feature to prevent unintentional or undesired falling of the core barrel assembly 110.
Additionally, as previously mentioned, the braking mechanism 132 can allow for variation in the inner diameter of the drill string 104, such as that associate with quick decent casings and drill rods. In particular, FIG. 6A illustrates a cross-sectional view of the head assembly 126 taken along the line 6-6 of FIG. 5 (i.e., through the braking elements 310). As shown by FIG. 6A, the landing member 312 can force the braking elements 310 radially outward into contact with the inner diameter 502 of the drill string 104. In at least one implementation, the landing member 312 can have a generally circular cross-section as shown by FIG. 6A, this call allow the braking elements 310 to roll along the drill string 104 as the core barrel assembly 110 is pumped down the drill sting 104.
As previously mentioned, in one or more implementations, the landing member 312 can include a taper such that varying the diameter of the landing member 312 varies along its length. This in combination with the biasing member 330 can ensure that the barking elements 310 maintain engagement with the inner diameter of the drill string 104 even if it varies. For example, FIG. 6B illustrates a cross-sectional view similar to that of FIG. 6A albeit with the braking mechanism positioned at a point in the drill string 104 having an inner diameter D2 larger that the inner diameter D1 of the drill string 104 shown in FIG. 6A. As shown, despite the change in inner diameter 502 of the drill string 104, the landing member 312 can ensure that the braking elements 310 maintain engagement with the inner diameter 502 of the drill string 104.
Referring now to FIG. 7, once the in-hole assembly or core barrel assembly 110 has reached its desired location within the drill string 104; the distal end of the core barrel assembly 110 can pass through the last drill rod and land on a landing ring that sits on the top of the outer tube 112. At this point, the braking elements 310 can be axially aligned with a first annular groove 700 in the drill string 104. At this point the biasing member 330 can more fully deploy, pushing the landing member 312 proximally thereby pushing the braking elements 310 radially outward into the first annular groove 700.
Furthermore, once the core barrel assembly 110 has landed on the landing ring of the outer tube 112, the first member 202 can move distally toward (and in some implementations at least partially into) the sleeve 204. This movement can cause the driving surfaces 304 drive the wedge members 300 radially outward (through the latch openings 306) and into engagement with the inner diameter 104 of the drill string 104. In particular, the wedge members 300 can be driven into engagement with a second annular groove 702 formed in the inner surface 502 of the drill string 104.
With the wedge members 300 deployed in the second groove 702, the driven latch mechanism 128 can lock the core barrel assembly 110 axially in the drilling position. In other words, the wedge members 300 and the annular groove 702 can prevent axial movement of the core barrel assembly 110 relative to the outer tube 112. In particular, the driven latch mechanism 128 can withstand the drilling loads as a sample enters the core barrel 124. Additionally, the drive latch mechanism 128 can maintain a deployed or latched condition despite vibration and inertial loading of mating head assembly components, due to drilling operations or abnormal drill string movement.
One will appreciate that the when in the drilling position, the biasing member 330 can force the driving member 302 distally, thereby forcing the wedge members 300 radially outward into the deployed position. Thus, the driven latch mechanism 128 can help ensure that the wedge members 300 do not disengage or retract unintentionally such that the core barrel inner tube assembly rises from the drilling position in a down-angled hole, preventing drilling, or falls un-announced from an up-angled drill hole. At the same time, the biasing member 330 can force the landing member 312 proximately, thereby forcing the braking members 310 radially outward into the extended position.
In addition to the foregoing, FIG. 7 further illustrates that when in the drilling position, the piston 344 can pass distally beyond the bushing 352. This can allow fluid to flow within the central bore 380, past the seal 130. Thus, the fluid control member 342 can allow drilling fluid to reach the drill bit 106 to provide flushing and cooling as desired or needed during a drilling process. One will appreciate in light of the disclosure herein that a pressure spike can be created and then released as the core barrel reaches the drilling position and the piston 344 passes beyond the bushing 352. This pressure spike can provide an indication to a drill operator that the core barrel assembly 110 has reached the drilling position, and is latched to the drill string 104.
In addition to axially locking or latching the core barrel assembly 110 in a drilling position, the driven latch mechanism 128 can rotationally lock the core barrel assembly 110 relative to the drill string 104 such that the core barrel assembly 110 rotates in tandem with the drill string 104. As previously mentioned, this can prevent wear between the mating components of the core barrel assembly 110 and the drill string 104 (i.e., the wedge members 300, the braking elements 310, the inner diameter 502 of the drills string 104, landing shoulder at the distal end of the core barrel, landing ring at the proximal end of the outer tube 112).
In particular, referring to FIG. 8 as the drill string 104 rotates (indicated by arrow 800), the core barrel assembly 110 and the driving member 302 can have an inertia (indicated by arrow 804) that without out the driven latch mechanism 128 may tend to cause the core barrel assembly 110 not to rotate or rotate a slow rate then the drill string 104. As shown by FIG. 8, however, rotation of the drill string 104 causes the wedge members 300 to wedge in between the driving surfaces 304 of the driving member 302 and the inner diameter 502 of the drill string 104 as the rotation of the drill string 104 tries to rotate the wedge members 300 relative to the driving member 302 (indicated by arrow 802). The wedging or pinching of the wedge members 300 in between the driving surfaces 304 and the inner diameter 502 of the drill string 104 and rotationally lock the driving member 302 (and thus the core barrel assembly 110) relative to the drill string 104. Thus, the driven latch mechanism 128 can ensure that the core barrel assembly 110 rotates together with the drill string 104.
One will appreciate in light of the disclosure herein that configuration of the driving surfaces 304 and the inner diameter 502 of the drill string 104 can create a circumferential taper as shown by FIG. 8. In other words, the distance between the inner diameter 502 of the drill string 104 and the driving member 302 can vary circumferentially. This circumferential taper causes the wedge members 300 to wedge in between or become pinched between the drill string 104 and the driving member 302, thereby rotationally locking the core barrel assembly 110 to the drill string 104.
As shown by FIG. 8, in at least one implementation, the circumferential taper between the drill string 104 and the driving surfaces 104 can be created by the planar configuration of the driving surfaces 304. In alternative implementations, the driving surfaces 304 may not have a planar surface. For example, the driving surfaces 304 can have a concave, convex, rounded, v-shape, or other configuration as desired. In any event, one will appreciate that the configuration of the driving surfaces 304 can create a circumferential taper between the driving member 302 and the inner diameter 502 of the drill string 104. In yet further implementations, the driving member 302 can have a generally circular cross-section, and the inner diameter 502 of the drill string 104 can include a configuration to create a circumferential taper between the inner diameter 502 of the drill string 104 and the driving surfaces 304 or driving member 302.
One will appreciate in light of the disclosure herein that the braking mechanism 132 can act to prevent proximal acting forces from moving the core barrel assembly 110 out of the drilling position, thereby preventing unintended or unwanted expulsion. For example, during drilling a pressure pocket or other anomaly in the formation 102 may be encountered that creates a proximately directed force during the drilling process. Such a force could force the piston 344 and driving member 302 proximately, which could potentially release the driven latch mechanism 128 (i.e., cause the wedge members 300 to radially retract out of the annular groove 702). This in turn could allow the proximal force to potentially shoot the core barrel assembly proximally up the drill string 104, or blow out the core barrel assembly 110. The braking mechanism can prevent such an occurrence.
In particular, if a proximally acting or disturbance force, acts to move the first member proximately relative to the sleeve 204 it will force the landing member 312 proximately. This in turn can force the tapered surface(s) of the landing member 312 to drive the braking elements 310 radially outward through the brake openings 314 and into engagement with the associated drill rod. The engagement between the braking elements 310 and the drill string 104 can act to counter the proximally acting or disturbance force thereby braking or stopping the head assembly 126 and preventing unwanted or unintended expulsion. The braking mechanism 132 can deployed by a proximally acting force, while the driven latch mechanism 128 is deployed or retracted, and/or during pumping in or retracting of the core barrel assembly 110.
At some point is may be desirable to retrieve the core barrel assembly 110, such as when a core sample has been captured. Referring to FIG. 9, in order to retrieve the core barrel assembly 110, a wireline 145 can be used to lower an overshot assembly 900 into engagement with the spearhead assembly 200. The wireline can then be used to pull the overshot 900 and spearhead assembly 200 proximally. This in turn can act to draw the first member 202 proximately away from the sleeve 204. Proximal movement of the first member 202 can cause the braking elements 310 to retract within the latch body 308, as the move along the landing member 312. Furthermore, proximal movement of the first member 202 can cause the wedge members 300 to radially retract as they move along the driving member 302. Once the first member 202 has been pulled proximately sufficiently to retract the braking mechanism 132 and the driven latch mechanism 128, the distal end of the mounting slots 324 can engage the pin 320, thereby pulling the sleeve 204 proximately.
As previously alluded to previously, numerous variations and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of this description. For example, core barrel assembly in accordance with the present invention can include a conventional latching mechanism (such as spring-driven pivoting latches or mechanical link latches) to provide axial locking, and a driven latch mechanism to provide rotational locking For example, this could be done by modifying a head assembly component such as a lower latch body to include roller elements that engage the inner diameter of the landing ring which sits in the outer tube. In such a configuration, the lower latch body can include driving surfaces and a retainer member that allows the roller elements to become wedged between the driving surfaces and the outer tube, thereby rotationally locking the lower latch body to the inner diameter of the landing ring. Thus, the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

## Claims

1. A core barrel head assembly having a longitudinal axis and configured to be removably received within a drill string, comprising:
a sleeve having a plurality of latch openings extending there through;
a driving member positioned at least partially within the sleeve, the driving member having an outer surface defining a plurality of discrete driving surfaces that are spaced circumferentially about the outer surface of a distal end of the driving member and that are distally tapered relative to the longitudinal axis of the core barrel head assembly, wherein, in cross-section of the driving member, each portion of each driving surface of the plurality of discrete driving surfaces has a radius relative to the longitudinal axis of the core barrel head assembly, and wherein the radius of at least a portion of each driving surface varies across the cross-sectional width of each driving surface; and
a plurality of wedge members, each wedge member of the plurality of wedge members being positioned on a portion of a respective driving surface of the plurality of driving surfaces, the plurality of wedge members extending within the plurality of latch openings about and between a released position and a locked position;
wherein each wedge member of the plurality of wedge members is unattached to other portions of the core barrel head assembly, and
wherein, when the plurality of wedge members are positioned in the locked position, the driving member is configured to wedge the plurality of wedge members between portions of the inner surface of the drill string and respective portions of the plurality of driving surfaces to axially and rotationally lock the core barrel head assembly relative to the drill string.

2. The core barrel head assembly as recited in claim 1, wherein the driving surfaces of the plurality of driving surfaces are planar.

3. The core barrel head assembly as recited in claim 1, wherein the wedge members of the plurality of wedge members are generally spherical.

4. The core barrel head assembly as recited in claim 1, wherein each respective driving surface of the plurality of driving surfaces has a minimal spacing from the longitudinal axis of the core barrel head assembly at the distal end of the driving member.

5. The core barrel head assembly as recited in claim 4, wherein axial translation of the driving member results in radial displacement of the plurality of wedge members between the released position and the locked position.

6. The core barrel head assembly as recited in claim 1, further comprising:
a valve positioned within the sleeve; and
a ball piston configured to engage the valve and prevent fluid from passing through the sleeve past the valve.

7. The core barrel head assembly as recited in claim 1, further comprising a biasing member configured to bias the driving member against the plurality of wedge members.

8. The core barrel head assembly as recited in claim 7, wherein the biasing member is positioned within the driving member.

9. The core barrel head assembly as recited in claim 1, further comprising a braking mechanism, the braking mechanism comprising a landing member and a plurality of braking elements.

10. The core barrel head assembly as recited in claim 9, wherein the braking elements of the plurality of braking elements are generally spherical.

11. The core barrel assembly as recited in claim 10, wherein axial translation of the landing member results in radial displacement of the plurality of braking elements between a retracted position and an extended position.

12. The core barrel head assembly as recited in claim 1, wherein at least a portion of each driving surface of the plurality of discrete driving surfaces is non-planar.

13. A core barrel head assembly having a longitudinal axis and configured to be removably received within a drill string, comprising:
a sleeve having a plurality of latch openings extending there through;
a driving member positioned at least partially within the sleeve, the driving member having an outer surface defining a plurality of discrete planar driving surfaces that are spaced circumferentially about the outer surface of a distal end of the driving member and that are distally tapered relative to the longitudinal axis of the core barrel head assembly; and
a plurality of generally spherical wedge members, each wedge member of the plurality of wedge members being positioned on a portion of a respective driving surface of the plurality of driving surfaces, the plurality of wedge members extending within the plurality of latch openings about and between a released position and a locked position,
wherein each wedge member of the plurality of wedge members is unattached to other portions of the core barrel head assembly, and
wherein, when the plurality of wedge members are positioned in the locked position, the driving member is configured to wedge the plurality of wedge members between portions of the inner surface of the drill string and respective portions of the plurality of driving surfaces to axially and rotationally lock the core barrel head assembly relative to the drill string.

14. The core barrel head assembly as recited in claim 13, wherein at a selected axial position relative to the longitudinal axis of the drill string, the distance between the inner surface of the drill string and the driving member varies circumferentially about the driving member.

15. The core barrel head assembly as recited in claim 13, wherein the driving member is configured to wedge the plurality of wedge members between the inner surface of the drill string and the plurality of driving surfaces upon rotation of the drill string.

16. The core barrel head assembly as recited in claim 13, further comprising:
a latch body moveably coupled to the sleeve;
a landing member positioned at least partially within the latch body; and
a plurality of braking elements positioned on the landing member, wherein axial movement of the landing member relative to the plurality of braking elements moves the plurality of braking elements radially relative to the latch body between a retracted position and an extended position.

17. The core barrel head assembly as recited in claim 16, further comprising a biasing member, wherein the biasing member biases the plurality of driving surfaces against the plurality of wedge members.

18. The core barrel head assembly as recited in claim 17, wherein the biasing member biases the landing member against the plurality of braking elements.