Note: Descriptions are shown in the official language in which they were submitted.
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GREASELESS CORE BARREL HEAD ASSEMBLY
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
the filing date of U.S.
Provisional Patent Application No. 63/236,108, filed August 23, 2021, which is
incorporated
herein by reference in its entirety.
FIELD
[0002] This disclosure relates generally to drilling
apparatuses and, more specifically,
to core sampling tools that collect core samples without the need for
delivering grease within
the core sampling tools.
BACKGROUND
[0003] Core barrel head assemblies conventionally use bearings
that rotationally
engage a spindle, which allows a proximal portion of the core barrel head
assembly to rotate
with the drill string while a core barrel (at a distal end of the core barrel
head assembly)
remains rotationally stationary to engage and receive a core sample. These
core barrel head
assemblies are provided with grease ports and grease fittings that permit
delivery of grease to
the bearings, which conventionally include rolling components. However, when
such grease
is delivered within the core barrel head assembly, hydrostatic fluid pressure
within a borehole
can allow grease to pass through small passageways within the core barrel head
assembly and
enter the core barrel, thereby leading to a loss of grease and corruption or
damage to the core
within the core barrel.
SUMMARY
[0004] Described herein is a core barrel head assembly having
a longitudinal axis.
The core barrel head assembly can comprise an elongate tube body having an
outer surface,
an interior cavity, a proximal end, and a distal end. The elongate tube body
can define a
helical groove that extends from the interior cavity to the outer surface of
the elongate tube
body. The helical groove can be configured to allow the elongate tube body to
elastically
extend from a neutral length to an elongated length.
[0005] The elongate tube body can define at least one aperture
that extends between
the interior cavity and the outer surface. The helical groove can be
configured to allow the
elongate tube body to elastically compress from the neutral length. The core
barrel head
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assembly can further comprise a valve body that is attached to the elongate
tube body and is
movable with respect to the proximal end of the elongate tube along the
longitudinal axis, as
the elongate tube body compresses, from a first position to a second position.
When in the
second position, the valve body causes a greater restriction to flow through
the at least one
aperture than when the valve body is in the first position.
[0006] The core barrel head assembly can further comprise an
electronics
compartment having an outer surface. The valve body can define an interior
cavity. The
electronics compartment can be disposed within the interior cavity of the
valve body. The
electronics compartment can be attached to the valve body so that the interior
surface of the
interior cavity of the valve body and the outer surface of the electronics
department define a
fluid passage. At least one of the valve body, the electronics compartment, or
a combination
of at least one interior surface of the valve body and at least one exterior
surface of the
electronics compartment can define at least one opening for providing fluid
communication
between the fluid passage and the distal end of the valve body.
[0007] A system can comprise a drill string comprising a drill
bit at a distal end, a
core barrel head assembly, wherein the core barrel head assembly has a distal
end, and a core
tube assembly attached to the core barrel head assembly. The core tube
assembly can
comprise a core barrel having a distal end and a core lifter case at the
distal end of the core
barrel. When the drill bit is in a drilling configuration, the drill bit is
spaced distally of the
core lifter case. When the drill bit is in a core break configuration, the
drill bit can be in
contact with the core lifter case, and the elongate tube can be elongated from
the neutral
length.
100081 A method can comprise retracting the drill string until
the drill bit is in the
core break configuration.
[0009] A core barrel head assembly can have a longitudinal
axis. The core barrel
head assembly can comprise an elongate tube body having an outer surface, an
interior
cavity, a proximal end, and a distal end. The elongate tube body can define at
least one
aperture that extends between the interior cavity and the outer surface and a
valve body that is
movable with respect to the proximal end of the elongate tube along the
longitudinal axis
from a first position to a second position_ When in the second position, the
valve body can
cause a greater restriction to flow through the at least one aperture than
when the valve body
is in the first position.
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[0010] The at least one aperture can define a total flow area
of about 0.3 square
inches.
[0011] The at least one aperture can have a width dimension
along the longitudinal
axis that is about 0.22 inches.
[0012] The elongate tube body can define a helical groove that
extends from the
interior cavity to the outer surface of the elongate tube body, wherein the
helical groove is
configured to allow the elongate tube body to elastically compress from a
neutral length.
[0013] The valve body can be attached to the distal end of the
elongate tube body.
100141 The core barrel head assembly can comprise an
electronics compartment
having an outer surface. The electronics compartment can be disposed within
the interior
cavity of the valve body. The electronics compartment can be attached to the
valve body so
that the interior surface of the interior cavity of the valve body and the
outer surface of the
electronics department define a fluid passage. At least one of the valve body,
the electronics
compartment, or a combination of at least one interior surface of the valve
body and at least
one exterior surface of the electronics compartment can define at least one
opening for
providing fluid communication between the fluid passage and the distal end of
the valve
body.
100151 A method can comprise advancing a drill string having a
distal end. The drill
string can comprise at least one drill rod defining an interior bore, a drill
bit at the distal end
of the drill string, and a core barrel head assembly. The core barrel head
assembly can have a
distal end and can be disposed within the interior bore of the at least one
drill rod. A core
barrel tube can be attached to the distal end of the core barrel head
assembly. A core sample
can be received in the core barrel tube until the elongate tube body
compresses to a length in
which the valve body is in the second position.
[0016] The method can further comprise retracting the drill
string until the elongate
tube body expands to a third length that is greater than the neutral length.
[0017] A core barrel head assembly can comprise a valve body
having a distal end
and a proximal end, wherein the valve body defines an interior cavity having
an interior
surface. An electronics compat ____ inient can have an outer surface. The
electronics
compartment can be disposed within the interior cavity of the valve body. The
electronics
compartment can be attached to the valve body so that the interior surface of
the interior
cavity of the valve body and the outer surface of the electronics department
define a fluid
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passage. At least one of the valve body, the electronics compartment, Or a
combination of at
least one interior surface of the valve body and at least one exterior surface
of the electronics
compartment can define at least one opening for providing fluid communication
between the
annular cavity and the distal end of the valve body.
[0018] The electronics compartment can house at least one of a
battery or an
electronic orientation instrument.
[0019] The fluid passage can be defined by the interior
surface of the interior cavity
of the valve body and the outer surface of the electronics department is an
annular cavity.
[0020] The electronics compartment can define the at least one
opening for providing
fluid communication between the fluid passage and the distal end of the valve
body.
[0021] A portion of the outer surface of the electronics
compartment can define at
least one male thread along a threaded length. The inner surface of the valve
body can define
at least one corresponding female thread. The electronics compartment can
threadedly
couple to the valve body via the at least one male thread and the
corresponding at least one
female thread. The at least one opening can extend through the electronics
compartment
along the threaded length.
[0022] The at least one opening can comprise a plurality of
openings separated by
respective radially extending webs.
[0023] The valve body can define the at least one opening for
providing fluid
communication between the fluid passage and the distal end of the valve body.
[0024] The combination of at least one interior surface of the
valve body and at least
one exterior surface of the electronics compartment can define the at least
one opening for
providing fluid communication between the fluid passage and the distal end of
the valve
body.
[0025] The core barrel head assembly can comprise a single
thrust bearing.
[0026] In some embodiments, the core barrel head assembly does
not comprise a
grease port.
[0027] In further embodiments, disclosed herein is a core
sampling tool, wherein the
core sampling tool comprises a core barrel and a core barrel head assembly
coupled to a
proximal end of the core barrel, wherein the core barrel head assembly does
not comprise a
grease port or a grease fitting. Optionally, in these embodiments, the core
barrel head
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assembly comprises a spindle and at least one bearing that rotationally
engages the spindle,
wherein the at least one bearing is a self-lubricating bearing. In some
aspects, the spindle is a
hollow spindle that defines a bore that extends axially through the spindle.
In these aspects,
the core barrel head assembly can include a check valve assembly, which can
positioned
distal or proximal of the hollow spindle. In further aspects, the spindle can
be a solid spindle
that does not define an axial bore extending through the spindle. In these
aspects, the core
barrel head assembly can include a check valve assembly, which can positioned
distal or
proximal of the hollow spindle.
[0028] In additional embodiments, disclosed is a core barrel
head assembly
configured for coupling to a core barrel. The core barrel head assembly can
include: an
elongate body having a proximal end and a distal en& a bearing subassembly
configured to
engage the proximal end of the elongate body; a spindle subassembly that is
rotationally
engaged by the bearing subassembly, wherein the spindle subassembly comprises
a hollow
spindle having an inner diameter of at least 5/8 inch, and wherein the bearing
subassembly
comprises one or more self-lubricating bearings. Optionally, the one or more
self-lubricating
bearings are solid oil bearings. In some aspects, the core barrel head
assembly does not
comprise a grease port or a grease fitting. In further aspects, the core
barrel head assembly
further comprises a check valve subassembly, wherein the check valve
subassembly engages
the distal end of the elongate body.
[0029] In further embodiments, disclosed is a method
comprising: advancing a core
sampling tool within a formation, the core sampling tool comprising a core
barrel head
assembly coupled to a core barrel; and receiving core within the core barrel,
wherein the
method does not comprise delivering grease to or within the core barrel head
assembly. In
these embodiments, the core barrel head assembly can include a bearing
subassembly that
rotationally engages a spindle, wherein the bearing subassembly comprises one
or more self-
lubricating bearings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] These and other aspects of the invention will become
more apparent in the
detailed description in which reference is made to the appended drawings
wherein:
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[0031] FIG. 1 is a side view of a drilling assembly in
accordance with embodiments
disclosed herein.
[0032] FIG. 2 is a cross sectional view of an inner tube
assembly of the drilling
assembly as in FIG. 1.
[0033] FIG. 3 is a perspective view of a core barrel head
assembly in accordance with
embodiments disclosed herein.
[0034] FIG. 4 is a side view of the core barrel head assembly
of FIG. 3.
[0035] FIG. 5 is a cross-sectional view of the core barrel
head assembly of FIG. 3.
[0036] FIG. 6 is a perspective sectional view of a valve body
and electronics
compartment of the core barrel head assembly as in FIG. 3.
[0037] FIG. 7 is a perspective view of another electronics
compartment for use with
the core barrel head assembly as in FIG. 3.
[0038] FIG. 8 is a perspective view of a valve body and yet
another electronics
compartment for use with the core barrel head assembly as in FIG. 3.
[0039] FIG. 9 is a perspective view of an elongate tube body
of the core barrel head
assembly of FIG. 3.
[0040] FIG. 10 is a cross-sectional view of the core barrel
head assembly of FIG. 3
when in a neutral configuration.
[0041] FIG. 11 is a cross-sectional view of the core barrel
head assembly of FIG. 3
when in a compressed configuration.
[0042] FIG. 12 is a cross-sectional view of the core barrel
head assembly of FIG. 3
when in an elongated configuration.
[0043] FIG. 13 is a partial cross-sectional view of a core
barrel head assembly having
another aperture profile.
[0044] FIG. 14 is a perspective view of the electronics
compartment as in FIG. 6.
[0045] FIG. 15 is a side view of an upper portion of the head
assembly as in FIG. 3,
detailing a latch mechanism.
[0046] FIG. 16 is a cross-sectional view of the upper portion
of the head assembly as
in FIG. 15 with a proximal body in a first position.
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[0047] FIG. 17 is a cross-sectional view of the upper portion
of the head assembly as
in FIG. 15 with a proximal body in a second position.
[0048] FIGS. 18A-18B are cross-sectional views of core ban-el
head assemblies
having grease ports.
[0049] FIG. 19 is an exploded view of an exemplary greaseless
core barrel head
assembly as disclosed herein.
[0050] FIG. 20 is a cross-sectional view of the core barrel
head assembly of FIG. 19,
with the head assembly shown in an assembled configuration.
DETAILED DESCRIPTION
[0051] The present invention can be understood more readily by
reference to the
following detailed description, examples, drawings, and claims, and their
previous and
following description. However, before the present devices, systems, and/or
methods are
disclosed and described, it is to be understood that this invention is not
limited to the specific
devices, systems, and/or methods disclosed unless otherwise specified, and, as
such, can, of
course, vary. It is also to be understood that the terminology used herein is
for the purpose of
describing particular aspects only and is not intended to be limiting.
[0052] The following description of the invention is provided
as an enabling teaching
of the invention in its best, currently known embodiment. To this end, those
skilled in the
relevant art will recognize and appreciate that many changes can be made to
the various
aspects of the invention described herein, while still obtaining the
beneficial results of the
present invention. It will also be apparent that some of the desired benefits
of the present
invention can be obtained by selecting some of the features of the present
invention without
utilizing other features. Accordingly, those who work in the art will
recognize that many
modifications and adaptations to the present invention are possible and can
even be desirable
in certain circumstances and are a part of the present invention. Thus, the
following
description is provided as illustrative of the principles of the present
invention and not in
limitation thereof
[0053] As used throughout, the singular forms -a,- -an,- and -
the- include plural
referents unless the context clearly dictates otherwise. Thus, for example,
reference to -an
aperture" can include two or more such apertures unless the context indicates
otherwise.
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[0054] Ranges can be expressed herein as from "about" one
particular value, and/or
to -about" another particular value. When such a range is expressed, another
aspect includes
from the one particular value and/or to the other particular value. Similarly,
when values are
expressed as approximations, by use of the antecedent "about,- it will be
understood that the
particular value forms another aspect. It will be further understood that the
endpoints of each
of the ranges are significant both in relation to the other endpoint, and
independently of the
other endpoint. Optionally, in some aspects, when values are approximated by
use of the
antecedent "about, "approximately," or "substantially," it is contemplated
that values within
up to 15%, up to 10%, up to 5%, or up to 1% (above or below) of the
particularly stated value
or characteristic can be included within the scope of those aspects.
[0055] As used herein, the term "proximal" refers to a
direction toward a drill rig or
drill operator (and away from a formation or borehole), while the term
"distal" refers to a
direction away from the drill rig or drill operator (and into a formation or
borehole).
[0056] As used herein, the terms "optional" or "optionally"
mean that the
subsequently described event or circumstance may or may not occur, and that
the description
includes instances where said event or circumstance occurs and instances where
it does not.
[0057] The word "or" as used herein means any one member of a
particular list and
also includes any combination of members of that list unless otherwise clear
from the
context.
[0058] Disclosed herein, with reference to FIGS. 1 and 2, is a
core barrel head
assembly 100 for use with a drilling system 10 that includes a drill head 12.
The drill head 12
can be coupled to a mast 14 that, in turn, is coupled to a drill rig 16. The
drill head 12 can be
configured to have one or more tubular threaded members 18 coupled thereto.
Tubular
members 18 can include, without limitation, drill rods, casings, and down-the-
hole hammers.
For ease of reference, the tubular members 18 will be described herein as
drill string
components. The drill string component 18 can in turn be coupled to additional
drill string
components 18 to form a drill or tool string 20. In turn, the drill string 20
can be coupled at a
distal end to a drilling tool 24, such as a rotary drill bit, a core sampling
drill bit (e.g., an
impregnated core sampling drill bit), or a percussive bit, configured to
interface with the
material, or formation 22, to be drilled. The drilling tool 24 can form a
borehole 26 in the
formation 22. The drilling tool 24 can further form a core sample (e.g., made
up of core,
rock, or other material within the formation 22) that can be received within
an inner tube
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assembly 90, comprising a core tube 130 and a core barrel head assembly 100,
as further
described herein. In various aspects, and as further disclosed herein, the
core barrel head
assembly 100 can comprise an indicator 302 that can be configured to detect a
force applied
to the core barrel assembly. The indicator can be used to determine whether
the core barrel is
full or whether the core is stuck within the core tube 130.
[0059] Referring to FIGS_ 3-12, described herein is a core
barrel head assembly 100
having a longitudinal axis 102. The core barrel head assembly 100 can comprise
an elongate
tube body 104 having an outer surface 106, an interior cavity 108, a proximal
end 110, and a
distal end 112. The proximal end 110 can define threads 114 (optionally,
female threads) that
couple to complementary threads 118 of a bearing housing 116. The bearing
housing 116 can
house a thrust bearing 120, or a plurality of thrust bearings 120 (e.g., two,
three, or more
thrust bearings 120). Optionally, the bearing housing 116 can further house a
lower thrust
bearing 122 configured to receive load during hoisting (or, optionally, a
plurality of such
bearings). In some aspects, the bearing housing 116 can comprise a grease port
124 for
providing grease to the thrust bearings 120 and/or the lower thrust bearing
122. Optionally,
in further aspects, the thrust bearings 120 and lower thrust bearing 122 can
each optionally be
greaseless. For example, the bearings 120 can be solid oil bearings. In this
way, the grease
port can be omitted, allowing for a longitudinally smaller configuration of
the bearing
housing 116, thereby allowing additional space for including other features
(e.g., electronics
or apertures 184). The thrust bearings 120 and lower thrust bearing 122 can
rotationally
engage a spindle 126. The spindle can allow an upper portion of the core
barrel head
assembly 100, including a latch body 128, to rotate with the drill string as
the core tube 130
(FIG. 2) at a distal end of the core barrel head assembly 100 remains
rotationally stationary to
engage a core sample.
[0060] The distal end 112 of the elongate tube body 104 can
define threads 132 for
threadedly coupling to valve body 140. The valve body 140 can have a distal
end 142, a
proximal end 144, and an outer surface 146. The valve body 140 can define a
valve seat 148
for engagement with a valve ball 150 to provide a check valve 152. The valve
body 140 can
define an interior cavity 154 having an interior surface 156. The interior
cavity 154 can
optionally be cylindrical. The valve body 140 can define female threads 158 at
the distal end
142 for threadedly coupling to the core tube 130 (FIG. 2).
100611 An electronics compartment 160 having an outer surface
162 can be disposed
at least partially within the interior cavity 154 of the valve body. The
distal end 142 of the
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valve body 140 can define female threads 156 that can threadedly couple to
male threads 168
on the outer surface 162 of the electronics compartment 160. The electronics
compartment
can define a hexagonal socket 163 that receives a hexagonal tool (e.g., an
Allen key) for
attaching to and removing the electronics compartment from the valve body. The
electronics
compartment 160 can define an interior volume 167 for housing a battery 164,
an electronic
orientation instrument 166, or both. The electronic orientation instrument 166
can comprise
various sensors (e.g., accelerometers, magnetometers, gyroscopes, etc.) that
can provide
orientation data of the electronic orientation instrument and, accordingly, a
core sample in the
core tube 130. Optionally, the internal volume 167 can be closed and sealed
with a threaded
cap 169. In addition to collecting sample orientation, sensors in the
electronic orientation
instrument 166 can collect information related to hole survey data, hole
geophysical data,
hole visual data, hole depth, tooling valve status, and further data as is
known in the art.
[0062] The outer surface 162 of the electronics compartment
160 and the inner
surface 156 of the interior cavity 154 can cooperate to define a fluid passage
170. The fluid
passage 170 can optionally be annular. The fluid passage 170 can enable fluid
to pass
therethrough for various functions, including, for example, lubricating the
drill bit during
drilling.
[0063] In some embodiments, the electronics compartment 160
can comprise at least
one opening 172 that provides fluid communication between the distal end of
the electronics
compartment 160 and the fluid passage 170. For example, the electronics
compartment 160
can comprise plurality of (e.g.. two) annular section openings 172 separated
by webs 174 that
extend along the length of the threads 168. Referring to FIG. 7, in still
further embodiments,
a valve body 140' and an electronics compartment 160' can cooperate to define
the one or
more openings 172'. For example, the threaded portion of the electronics
compartment can
comprise a plurality (e.g., two or three) sections 176 having longitudinally
extending gaps
178 therebetween. The threads 156 of the valve body 140 and the gaps 178 of
the electronics
compartment can cooperate to provide the openings 172'. Referring to FIG. 8,
in further
embodiments, a valve body 140" can define the one or more openings 172" that
provide fluid
communication between the distal end of the electronics compartment 160- and
the fluid
passage 170.
[0064] Including the electronics compartment 160 within the
core barrel head
assembly 100 can consume space (particularly, linear space) within the core
barrel head
assembly 100. In order to accommodate the electronics compartment 160, one or
more of the
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following optional aspects can be implemented. In some embodiments, greaseless
bearings
can be used, thereby eliminating the grease fitting and allowing for a shorter
bearing housing.
In addition, or alternatively, a single thrust bearing (optionally, a
greaseless bearing) can be
substituted for the conventional plurality of thrust bearings 120. The single
thrust bearing
can have a greater load rating than the thrust bearings of configurations
having a plurality of
thrust bearings. The bearing can have a load rating that exceeds the thrust
capacity of the
drill bit. Accordingly, the bearing can have a load rating that varies
depending on the core
size. For an NQ size drill bit having an outer diameter of 75.7 mm and an
inside diameter of
47.6 mm, for example, the thrust bearing can have a dynamic load of at least
8,500 lbf.
According to some optional aspects, conventional shut-off valves that detect
when the core
tube is full or jammed can be eliminated, and, instead, drill load sensing can
be used to
determine when the core tube is full or jammed. Optionally, conventional core
break springs
and shut-off valve springs can be integrated into the body of the core barrel
head assembly, as
further disclosed herein. Thus, the elongate tube body 104 and valve body 140
can cooperate
to serve as the indicator 302.
100651 The elongate tube body 104 can define at least one
helical groove 180 that
extends around the circumference of the elongate tube body 104 and along the
longitudinal
axis 102. As used herein, "helical" should be understood to mean a path that
wraps around
the circumference and extends along the length of the elongate tube.
Accordingly, the helical
groove 180 as disclosed herein, should be understood to include, for example,
a groove
having a continuous profile and a constant pitch (as shown), a groove having a
varying pitch,
and a stair step groove that alternatingly extends in a purely longitudinal
direction for a
segment and in a purely circumferential direction for another segment. In some
embodiments, the helical groove 180 can comprise a spiral shape having a
constant pitch.
Optionally, the helical groove 180 can comprise about three revolutions around
the
circumference of the elongate tube body 104. According to at least one
optional
embodiment, the helical groove 180 can be about 0.35 inches wide and can have
circular
stress relief features at each end. The circular stress relief feature at the
distal end of the
helical groove 180 can be about .75 inches in diameter, and the stress relief
feature at the
proximal end of the helical groove 180 can be about 0.5 inches in diameter.
The pitch of the
groove can optionally be about 1.7 rotations per inch. It should be understood
that the
disclosed dimensions are optional and that the dimensions can be selected to
provide
operative aspects as further disclosed herein.
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[0066] The helical groove 180 can enable the elongate tube
body 104 to compress
from a neutral length 190 (i.e., the length of the elongate tube when neither
in compression
nor tension, as shown in FIG. 10). The elongate tube body 104 can define one
or more
apertures 184 that extend between the outer surface 106 and the interior
cavity 108.
Optionally, the elongate tube body 104 can define two slot-shaped apertures
that are spaced
180 degrees about the circumference of the elongate tube body. The aperture(s)
184 can be
elongated about the circumference of the elongate tube body. The aperture(s)
184 can be
disposed along the length of the elongate tube body 104 so that when the
elongate tube body
104 is in the neutral length, each of the apertures 184 is at least partially
open, and when the
elongate tube body 104 is compressed from the neutral length 190, the proximal
end 144 of
the valve body 140 blocks or substantially blocks the aperture(s) 184. In this
way, as the drill
string is advanced within a borehole, if the core tube jams or core tube is
full, the elongate
tube body 104 can compress. As the elongate tube body 104 compresses, the
valve body 140
can move proximally with respect to the proximal end of the elongate tube body
140 to block
each aperture 184. In some embodiments, the valve body 140 can entirely block
each
aperture 184. In further embodiments, the valve body 140 can partially reduce
the effective
area of each aperture 184. That is, in partially blocking each aperture 184,
the valve body can
reduce a minimum cross sectional area through which fluid can flow from the
interior cavity
to the outer surface. In some situations, it can be beneficial to only
partially block each
aperture 184 to allow some flow therethrough, which can provide circulation to
the drill bit.
[0067] Thus, the valve body 140 can cause a greater flow
restriction through the
aperture(s) 184 as the valve body moves proximally with respect to the
proximal end of the
elongate tube body 104. In at least some drilling systems, a pressure relief
valve can regulate
a maximum pressure. According to some aspects, when the valve body 140 blocks
the
aperture(s) 184, the pressure can rise beyond the set pressure of the pressure
relief valve to
thereby cause the valve to open and, thereby, indicate that the core tube is
full. It is
contemplated that the change in flow restriction can be reflected as a change
in the
percentage of the two-dimensional area of the aperture 184 that is blocked by
the valve body
140. Optionally, the change in the percentage of the area of the aperture that
is blocked by
the valve body can be at least 20%, at least 40%, at least 60%, at least 80%,
at least 90 %, at
least 95%, at least 99%, or, optionally, be about 100%. It is understood that
the percentage
change in blocked area should be sufficient to distinguish from minor
variations in the
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relative positioning of the valve body that are not associated with proximal
movement of the
valve body for purposes of causing greater flow restriction.
[0068] Optionally, it is contemplated that the valve body 140
can be moveable about
and between a fully -open- position in which about 50% of the aperture 184 is
blocked and a
fully -closed- position in which 100% of the aperture is blocked. Optionally,
when the valve
body is in the fully "open" position, the area of the aperture that is blocked
by the valve body
can range from about 0.1 square inches to about 0.25 square inches. When the
valve body is
in the fully "closed" position, the area of the aperture that is blocked by
the valve body can
range from about 0.25 square inches to about 0.5 square inches. Optionally, it
is
contemplated that the change in flow restriction can correspond to a change in
"blocked area"
of the aperture of at least 0.01 square inches, at least 0.05 square inches,
at least 0.1 square
inches, or at least 0.2 square inches. It is understood that the change in
blocked area should
be sufficient to distinguish from minor variations in the relative positioning
of the valve body
that are not associated with proximal movement of the valve body for purposes
of causing
greater flow restriction.
[0069] Optionally, when the valve body causes a complete or
substantially complete
flow restriction, the greater flow restriction can correspond to a maximum
pressure setting (as
measured by the operator, such as with a pump). However, if the valve body 140
causes only
a partial flow restriction, then the greater flow restriction can correspond
to a pressure less
than the maximum pressure setting. The changing flow restriction can cause the
fluid
pressure to change, and a drill operator can detect the change in fluid
pressure. Optionally,
the change in fluid pressure can be at least 20%, at least 25%, at least 30%,
at least 35%, at
least 40%, at least 45%, or at least 50%. The change in fluid pressure can
indicate to the drill
operator that the core sample is jammed or that the core tube is full. In some
embodiments,
an alarm can activate when the fluid pressure passes a threshold to notify the
operator that the
core tube is full or jammed. Optionally, the alarm can be triggered manually
by the drill
operator. Alternatively, the alarm can be triggered automatically in response
to a change
detected by a pressure sensor associated with the drill string (optionally, a
sensor housed
within the electronics compartment 160), with the detected change in pressure
being
indicative of a full or jammed core tube.
[0070] It should be understood that in some situations during
drilling, particularly
through difficult ground conditions, the valve body 140 can block and unblock
the aperture(s)
184 in rapid succession. Whether automatically or by operator interpretation,
this rapid
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blocking and unblocking can be differentiated from when core tube is full,
causing the valve
body to block the aperture(s) for a continuous period of time.
[0071] Optionally, the proximal end 144 of the valve body 140
can have a turned
down (downwardly facing) portion that defines a shoulder 196. The interior
surface of the
elongate tube body 104 can define a complementary shoulder 198 that can act as
a stop that
engages the shoulder 196 of the valve body 140. In this way, the elongate tube
body 104 can
be limited to a minimum compressed length 192 (FIG. 11).
[0072] The aperture(s) 184 can have a cross sectional area (in
the case of a plurality
of apertures, a combined cross sectional area) in a radial dimension that is
perpendicular to
the longitudinal dimension, wherein the cross sectional area is selected to be
at least as large
as the minimum cross sectional area in the head assembly so that flow through
the aperture
does not increase flow restriction during drilling. Moreover, the apertures
provide transition
porting from the head porting to the flow path 170. which provides a pressure
drop, so an
oversized aperture or oversized apertures can be beneficial in minimizing
pressure drop along
the core barrel head assembly 100. The size of the aperture(s) 184 in the
longitudinal
dimension 102 can be limited based on compressibility of the elongate tube
body 104 or other
such limits. That is, because the compressible displacement of the elongate
tube body 104
and, thus, the travel of the valve body 140 is limited, the geometry and size
of the aperture(s)
can be limited in order to significantly restrict the flow through the
aperture(s). Accordingly,
in some embodiments, the size of the aperture(s) 184 in the longitudinal
dimension 102 can
be less than a quarter inch, or about 0.22 inches.
[0073] Referring to FIG. 2, the core barrel head assembly 100
can comprise a core
lifter case 134 attached at a distal end of the core tube 130. A core lifter
136 can move within
the core lifter case 134 to engage and grip the core sample during core break
and core
retrieval. A non-limiting example of a core lifter in accordance with
embodiments disclosed
herein is provided in U.S. Patent No. 8,770,320 to Drenth et al., issued July
8, 2014, the
entirety of which is hereby incorporated by reference herein.
[0074] The core barrel head assembly 100 can be positioned at
a distal end of the drill
string 20 and engage the drill string via latches 210. During drilling
operations, the drill bit
can be spaced from the core lifter case to provide a bit gap 212 that allows
fluid to pass
therethrough and lubricate the drill bit. During core break, the drill string
is lifted until the bit
gap is closed so that the bit can pull on the distal end of the core lifter
case. Conventional
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core barrel head assemblies comprise a compressible core break spring that
compresses to
keep the core tube in a fixed longitudinal position so that the core tube does
not move with
respect to the core sample. According to some aspects, the conventional core
break spring
can be eliminated, and the elongate tube body 104 can extend under tension
from the neutral
length 190 to an elongated length 194 (FIG. 11) at which point the drill bit
engages the core
lifter. In this way, the elongate tube body 104 can replace the conventional
core break spring.
That is, as the drill string is retracted in the proximal direction 30 (FIG.
1), the upper portion
of the core barrel head assembly 100 rests on a landing ring of the drill
string and, thus moves
upward with the drill string. As the core tube 130 stays in a fixed position
with respect to the
core sample and, thus, the formation, the elongate tube body 104 can elongate
to a length at
which the system is in a core break configuration in which the bit gap is
closed and the drill
bit engages the core lifter case. The various elongate tube bodies can
optionally have
apertures at various positions along their respective lengths.
[0075] The material of the elongate tube body 104 can be
selected to have an elastic
modulus that provides significant and linear load response to small
displacements. The
material can optionally be traditional metals, or, in further embodiments,
engineered
amorphous metals, engineered composite metals, etc. In addition to the
material, the outer
diameter of the elongate tube body 104, wall thickness, and the groove
dimensions and
geometry can be selected to provide a body having a desired spring constant
while allowing
for purely elastic deformation. For example, according to some aspects, the
spring constant
can be about 11,110 lbf/in. for an NQ drill bit size. Optionally, the spring
constant can be
selected based on the material of the formation (and the recovered core
sample). For
example, granite can have a tensile strength of 2000 psi. Accordingly, the
spring constant
can be selected to allow compression and elongation for various materials.
Optionally, the
spring constant can range from about 10,000 lbf/in. to about 12,000 lbf/in. In
still further
embodiments, the at least one helical groove can comprise a plurality of
grooves, such as, for
example, dual grooves that are separated by 180 degrees about the
circumference of the
elongate tube body 104. A desirable spring constant can have a significant
load resistance
that allows the drill to push the sample tube through sticky/swelling clays or
problematic
ground conditions without compressing the elongate tube body 104 until the
valve body 140
blocks or sufficiently blocks the aperture(s) 184, thereby falsely indicating
that the core tube
130 is full. According to various embodiments, an operator can select from
various elongate
tube bodies 104 having various spring constants based on ground conditions.
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[0076] In order to use a single spring for both core break and
detection of a jammed
or full core tube, it is beneficial to account for certain parameters. The
elongate tube body
104 should be able to elastically extend the length of the bit gap. Moreover,
the elongate tube
body 104 must provide enough spring tension once extended to the elongated
length 194
(when the drill bit engages the core lifter case) in order to allow the core
lifter to seat in
between the core sample and the core lifter case. The aperture 184 can be
positioned along
the length of the elongate tube body 104 so that, for the spring constant
provided by the
elongate tube body, a select force causes the valve body 140 to block the
aperture 184. The
spring force of the elongate tube body 104 when the elongate tube body is in
the compressed
configuration 194 can optionally match the spring constant of a compression
spring used in
conventional shut-off valves for detecting when the core sample is full.
Further, the valve
body can block the valve aperture at a load that is similar to that of a
conventional shut-off
valve. In some embodiments, conventional shut-off valves can close under a
load of about
2500 lbf, although the load can vary depending on the size and configuration.
[0077] A core bit can be used to collect a core sample is a
hollow cylinder with a
cutting surface on one face of the hollow cylinder. The core bit can be
fixedly attached on
one end of a cylindrical drill rod and inserted into a previously drilled bore
hole. New
sections of drill rods can be added to the upper end of the original rod,
creating a series of
connected drill rods in what is termed a drill string, as the core bit is
pushed into the borehole.
Each section of drill rod can be on the order of 10 feet long. When the core
bit reaches the
bottom of the borehole, the core bit can be forced against a rock strata as
the core bit is
rotated by rotating the drill string. The combination of the force and the
rotating cutting
surface can cut a cylindrical core sample from the rock strata. Drilling fluid
can be pumped
into the borehole to cool and lubricate the drill bit. Optionally, the
drilling fluid can pass
down the drill string and through a bit gap, as disclosed herein, between the
core lifter case
and the drill bit. The core sample can be captured in an interior portion of
the drill string,
within the core tube, behind the core bit until the core sample can be
retrieved from the
borehole. The length of an interior tube containing a core barrel is typically
five feet to 30
feet in length.
[0078] The drill string can be retracted, thereby engaging the
core lifter to seat
between the core sample and the core lifter case. In doing so, the bit gap can
close so that the
drill bit biases against the core lifter case. As the drill string is further
retracted, the
engagement between the core lifter applies tension to the core, thereby
causing a core break,
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whereby the core sample separates from the formation. The inner tube assembly
with the
core sample inside can be retrieved via wireline to retrieve the core sample
from the bore.
[0079] It is contemplated that, in some optional aspects, it
can be desirable for the
core barrel head assembly 100 to have different spring rates for core break
(spring tension)
and for valve shutoff (blocking the apertures 184 in spring compression). For
example, valve
shutoff can require substantially smaller forces than core break. Accordingly,
in some
aspects, the core barrel head assembly 100 can have a first spring rate in
tension that is
configured for spring break and a second spring rate in compression that is
configured for
allowing compression. Optionally, this can be accomplished via compound
springs. For
example, a second spring (not shown) can be configured to apply a spring force
for only a
portion of the travel between the proximal end 110 and the distal end 112
between the
elongate length and the compressed length. Said second spring can optionally
be a
compression spring or a tension spring.
[0080] Optionally, in still further aspects, it is
contemplated that the spring rate can be
variable. For example, the helical groove 180 that defines the spring can have
a variable
pitch. In this way, movement between the proximal end 110 and distal end 112
of the
elongate tube body 104 can be subject to a nonlinear spring force between the
elongate length
and the compressed length.
100811 In still further aspects, it is contemplated that,
instead of the valve body 140
moving axially to block the apertures 184, the core barrel head assembly 100
can comprise a
conventional valve comprising a radially expandable valve ring to serve as the
indicator 302.
For example, in some embodiments, the lower core barrel may also comprise one
or more
compression washers that restrict the flow of drilling fluid once the core
sample tube is full,
or once a core sample is jammed in the core sample tube. The compression
washers can be
axially compressed when the drill string and the upper core barrel press in
the drilling
direction, but the core sample tube does not move axially because the sample
tube is full or
otherwise prevented from moving downwardly with the drill string. This axial
compression
causes the washers to increase in diameter so as to reduce, and eventually
eliminate, any
space between the interior surface of the drill string and the outer perimeter
of the washers.
As the washers reduce this space, they can cause an increase in drilling fluid
pressure. This
increase in drilling fluid pressure may function to notify an operator of the
need to retrieve
the core sample and/or the inner core barrel.
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[0082] In yet further aspects, and with reference to FIG. 2,
the indicator 302 of the
core barrel head assembly 100 can optionally comprise or be a load cell that
is configured to
measure axial force on the core tube. Thus, the load cell can serve as the
indicator 302. The
load cell can be in communication with a computing device via conventional
communication
means for providing feedback to an operator. The measured axial force can
indicate that the
core sample is stuck/jammed within the core tube. In further aspects, the
measured axial
force can indicate that the core barrel is full.
[0083] In further aspects, the disclosed core barrel
assemblies can comprise latch
mechanisms and latch-seat features as are known in the art. In these aspects,
it is
contemplated that the latch mechanisms and latch-seat features can have
significant tolerance
and axial movement such that, during a core block or jamming event, the
landing shoulder of
the head assembly can lift off of the mating landing ring in the outer tube
assembly and
provide fluid bypass, thereby causing a fluid pressure drop that can serve as
an indication of a
core jamming in the core tube.
[0084] Referring to FIGS. 15-17, the head assembly can
comprise a latch mechanism
300 that is configured to engage the inner wall of the drill string to retain
the head assembly
100 in position relative to the longitudinal axis of the drill string. The
latch mechanism 300
can comprise latch body 304 that defines a plurality of through holes 306 that
receive
respective wedge members 308. The latch mechanism can further comprise a
proximal body
310 that is receivable into the latch body and is axially movable relative to
the latch body.
The proximal body can comprise a circumferential surface 312 that defines one
or more
wedge surfaces 314 that are configured to drive the respective wedge members
outwardly
through the respective through-holes in the latch body when the proximal body
is in a first
axial position (FIG. 16) relative to the latch body. Optionally, the wedge
members 308 can
be balls, rollers, cams, or other suitable members that are configured to
wedge against the
inner walls of the drill string.
[0085] The proximal body can be configured to couple to a
wireline (e.g., via a
conventional spearhead coupling) to thereby receive a proximal force. The
proximal force
can move the proximal body 310 to a second axial position (FIG. 17) relative
to the latch
body 304. When the proximal body 310 is in the second axial position relative
to the latch
body that is proximal of the first axial position, the circumferential surface
312 of the
proximal body can define a radially recessed portion 318 that allows the wedge
members 308
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to move radially inwardly to disengage from the inner surface of the drill
string, thereby
allowing the head assembly to move relative to the drill string.
[0086] A detent can retain the proximal body in its first and
second positions. For
example, an inner extension 320 can be fixedly coupled to the latch body
(e.g., via a spring
pin coupling) so that the inner extension cannot move axially relative to the
latch body. The
inner extension can define a groove that can receive a canted-coil spring 326_
The proximal
body can define a first shoulder 322 and a second shoulder 324 that are
axially spaced from
each other. The canted coil spring 326 can engage the first and second
shoulders when the
proximal body is in the first and second position, respectively, to serve as a
detent to retain
the proximal body in each position. That is, when the proximal body is in the
first position,
the canted coil spring can bias against the first shoulder when to inhibit
movement of the
proximal body toward the second position. When the proximal body is in the
second
position, the canted coil spring can bias against the second shoulder to
inhibit movement of
the proximal body toward the first position.
Core Barrel Head Assemblies Comprising Self-Lubricating Bearings
[0087] As described above, it is contemplated that the core
barrel head assembly 100
disclosed herein can comprise greaseless and/or self-lubricating bearings
(e.g., greaseless or
self-lubricating thrust bearings). More generally, in various exemplary
aspects, a core
sampling tool can be configured to receive and collect a core sample during a
drilling
operation without the need for using grease to lubricate bearing components in
proximity to a
core barrel.
[0088] As shown in FIGS. 18A-18B, core barrel head assemblies
have conventionally
included grease ports 400 and/or grease fittings that are needed to deliver
grease to thrust
bearings 402 that are coupled to a spindle 404. FIG. 18A depicts a solid
spindle 404, to
which a single thrust bearing 402 is coupled. The grease port 400 is
positioned distally of the
spindle 404. When grease 410 enters the core barrel head assembly through the
grease port
400, grease fills the inner tube cap 406 before moving proximally to the
thrust bearing 402.
Under certain environmental conditions and pressures, this design allows
grease to enter a
core barrel through a check valve assembly 408 positioned distal of the inner
tube cap 406.
FIG. 18B depicts two thrust bearings 502 that are coupled to a hollow spindle
504_ The
grease port 400 is positioned in proximity to the thrust bearings. When grease
410 enters the
core barrel head assembly, the grease travels in both directions, filling
portions of the inner
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tube assembly. Under pressure, grease 410 can escape through a bushing 506
that surrounds
the distal end of the spindle 504 in proximity to the inner tube, thereby
allowing grease to
enter the core barrel. In these designs, the grease is not distributed
efficiently to the bearings,
and the presence of grease within the core barrel can corrupt or damage core
samples or
otherwise complicate the core analysis process.
[0089] In exemplary aspects, and with reference to FIGS. 19-
20, a greaseless core
sampling tool can comprise a core barrel (such as the core tube 130 described
above) and a
core barrel head assembly 100 coupled to a proximal end of the core barrel.
Optionally, in
these aspects, the core barrel head assembly does not comprise a grease port
or a grease
fitting. In further aspects, and as shown in FIGS. 19-20, the core barrel head
assembly 100
can comprise a spindle 126 and at least one bearing 120 (optionally, a
plurality of bearings)
that rotationally engages the spindle. In these aspects, it is contemplated
that each bearing
120 of the at least one bearing can be a self-lubricating bearing, such as,
for example and
without limitation, a solid oil bearing (such as those manufactured by SKF).
Such solid oil
bearings can comprise oil-saturated, polymer material that is molded into the
structure of the
bearing, thereby forming narrow gaps between rolling elements of the bearing
and enabling
the bearing to rotate freely. Optionally, the solid oil bearings can have a
porous structure
with pores that retain lubricating oil by surface tension, with all or
substantially all free space
in the bearing being filled and a minimum amount of oil being released into
the narrow gaps.
In use, it is contemplated that such solid oil bearings are lubricated for the
life of the bearing
without the need for re-lubrication¨indeed, in exemplary configurations, such
solid oil
bearings cannot be re-lubricated.
[0090] FIG. 19 illustrates an exemplary embodiment of core
barrel head assembly
100. The portions of the core barrel head assembly can include any component
or
characteristic suitable for use with an inner core barrel. In some
embodiments, as shown in
FIG. 19, the inner tube head assembly 100 can comprise a spearhead 500 (for
coupling with
an overshot), a retracting case 510 (or other driving member, for deploying
and retracting
latch members 129), upper and lower latch bodies 128a, 128b, a valve ring 515
(as a
component of a fluid control valve), a landing shoulder 520 (for retaining the
core barrel at a
desired distance from the distal (drilling) end of the drill string), a
compression washer
assembly 530 (that restricts the flow of drilling fluid once the core barrel
is full, or once a
core sample is jammed in the core barrel), and/or a spring 540 (optionally
provided as a
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component of a core breaking apparatus). The functions of these components are
generally
known and are not described in detail herein.
[0091] In exemplary aspects, and as shown in FIG. 20, the
spindle 126 can be a
hollow spindle that defines a bore 127 that extends axially through the
spindle. In use, it is
contemplated that the bore 127 can define at least a portion of an inner
channel through the
core barrel head assembly 100. In use, it is contemplated that the bore 127 of
the hollow
spindle can increase productivity by allowing fluid to flow directly through
the lower core
barrel. It is further contemplated that the disclosed core barrel head
assembly 100 can fully
provide the benefits of the hollow spindle (without grease entering the
sampling inner tube)
while also providing design simplifications, along with improved productivity
and reliability
that is achieved by avoiding the maintenance of greased bearings.
[0092] In these aspects, it is contemplated that the core
barrel head assembly 100 can
further comprise a check valve assembly, which can optionally be provided as a
valve body
140 that defines a valve seat 148 for engagement with a valve ball 150. in
some
configurations, it is contemplated that the check valve assembly can be
positioned distal of
the spindle 126 (optionally, near or within the inner tube cap). In other
configurations, it is
contemplated that the check valve assembly can be positioned proximal of the
spindle 126.
[0093] In other exemplary aspects, the spindle 126 can be a
solid spindle that does not
define an axial bore extending through the spindle. In these aspects, it is
contemplated that
the core barrel head assembly 100 can further comprise a check valve assembly,
which can
optionally be provided as a valve body 140 that defines a valve seat 148 for
engagement with
a valve ball 150. In some configurations, it is contemplated that the check
valve assembly
can be positioned distal of the spindle 126. In other configurations, it is
contemplated that the
check valve assembly can be positioned proximal of the spindle 126.
Optionally, the check
valve subassembly can engage the distal end 112 of the elongate body 104. In
use, it is
contemplated that the check valve assembly can allow fluid to flow from the
core sample
tube to the bore of the hollow spindle, but not allow fluid to flow from the
inner channel to
the core sample tube. Accordingly, the check valve may allow fluid to pass
into the inner
channel and then through the inner core barrel when the inner core barrel is
being tripped into
the drill string and when core sample tube is empty. In this manner, fluid
resistance can be
lessened so the inner core barrel can be tripped into the drill string faster
and more easily. On
the other hand, when the inner core barrel is tripped out of the drill string,
the check valve can
prevent fluid from pressing down on a core sample contained in core sample
tube.
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Accordingly, the check valve may prevent the sample from being dislodged or
lost. And
when the check valve prevents fluid from passing through the lower core barrel
and into the
core sample tube, the fluid may be forced to flow around the outside of the
core sample tube
and the lower core barrel.
[0094] In some aspects, the core barrel head assembly 100 can
comprise an elongate
body 104 having a proximal end 110 and a distal end 112. The core barrel head
assembly
100 can further comprise a bearing subassembly configured to engage the
proximal end 110
of the elongate body 104. In use, the bearing subassembly can allow the core
sample tube to
remain stational), while the upper core barrel and drill string rotate. In
exemplary aspects, the
bearing subassembly can be provided as a bearing housing 116 (spindle bushing)
that
receives at least one bearing 120. In exemplary aspects, each bearing 120 of
the bearing
subassembly can be a self-lubricating bearing (for example, a solid oil
bearing (such as those
manufactured by STU). The core barrel head assembly 100 can further comprise a
spindle
subassembly that is rotationally engaged by the bearing subassembly. In
exemplary aspects,
the spindle subassembly can comprise a hollow spindle 126 having an inner
diameter of at
least 5/8 inch (optionally, ranging from about 5/8 inch to about 1 inch). In
further aspects,
the core barrel head assembly 100 does not comprise a grease port or a grease
fitting. In still
further aspects, the core barrel head assembly 100 does not comprise a check
valve that is
configured to manage the flow of grease within the core barrel head assembly.
[0095] By eliminating grease ports and grease fittings from
the core barrel head
assembly, it is contemplated that the space within the head assembly
previously occupied by
the grease ports and grease fittings can permit enlargement of the inner
diameter of the bore
127 of the hollow spindle 126, thereby allowing improved fluid bypass during
tripping into a
borehole, resulting in increased tripping speeds. Additionally, by removing
the grease port
and simplifying the structure of the spindle assembly, it is contemplated that
the distal end of
the spindle 126 can be positioned near or within the inner tube cap, thereby
providing more
direct fluid flow between the inner tube and the spindle.
[0096] In exemplary aspects, a method of collecting a core
sample can comprise
advancing a core sampling tool (e.g., the core barrel head assembly 100)
within a formation.
In these aspects, the core barrel head assembly 100 can be coupled to a core
barrel 130, and
the method can further comprise receiving core within the core barrel 130. In
exemplary
aspects, the method does not comprise delivering grease to or within the core
barrel head
assembly. As further disclosed herein, the core barrel head assembly can
comprise a bearing
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subassembly and a spindle, and the bearing subassembly can comprise one or
more self-
lubricating bearings that rotationally engage the spindle.
Exemplary Aspects
[0097] In view of the described devices, systems, and methods
and variations thereof,
herein below are described certain more particularly described aspects of the
invention.
These particularly recited aspects should not however be interpreted to have
any limiting
effect on any different claims containing different or more general teachings
described
herein, or that the "particular" aspects are somehow limited in some way other
than the
inherent meanings of the language literally used therein.
[0098] Aspect 1: A core barrel head assembly having a
longitudinal axis, the core
barrel head assembly comprising: an elongate tube body having an outer
surface, an interior
cavity, a proximal end, and a distal end, wherein the elongate tube body
defines a helical
groove that extends from the interior cavity to the outer surface of the
elongate tube body,
wherein the helical groove is configured to allow the elongate tube body to
elastically extend
from a neutral length to an elongated length.
[0099] Aspect 2: The core barrel head assembly of aspect 1,
wherein the elongate
tube body defines at least one aperture that extends between the interior
cavity and the outer
surface, wherein the helical groove is configured to allow the elongate tube
body to
elastically compress from the neutral length, wherein the core barrel head
assembly further
comprises a valve body that is attached to the elongate tube body and is
movable with respect
to the proximal end of the elongate tube body along the longitudinal axis, as
the elongate tube
body compresses, from a first position to a second position, wherein, when in
the second
position, the valve body causes a greater restriction to flow through the at
least one aperture
than when the valve body is in the first position.
[00100] Aspect 3: The core barrel head assembly of aspect 2,
further comprising an
electronics compartment having an outer surface, wherein the valve body
defines an interior
cavity, wherein the electronics compartment is disposed within the interior
cavity of the valve
body, wherein the electronics compartment is attached to the valve body so
that the interior
surface of the interior cavity of the valve body and the outer surface of the
electronics
department define a fluid passage, wherein the valve body, the electronics
compartment, or a
combination of at least one interior surface of the valve body and at least
one exterior surface
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of the electronics compartment defines at least one opening for providing
fluid
communication between the fluid passage and the distal end of the valve body.
[00101] Aspect 4: A drilling system comprising: a drill string
having: a drill bit at a distal
end of the drill string; a core barrel head assembly of any of claims 1-3,
wherein the core
barrel head assembly has a distal end; and a core tube assembly attached to
the core barrel
head assembly, wherein the core tube assembly comprises: a core barrel having
a distal end;
and a core lifter case at the distal end of the core barrel; wherein, when the
drill bit is in a
drilling configuration, the drill bit is spaced distally of the core lifter
case, and wherein, when
the drill bit is in a core break configuration, the drill bit is in contact
with the core lifter case,
and the elongate tube is elongated from the neutral length.
[00102] Aspect 5: A method comprising: positioning the drill
string of the system of
aspect 4 within a borehole; receiving a core sample within the core barrel;
and retracting the
drill string until the drill bit is in the core break configuration.
[00103] Aspect 6: A core barrel head assembly having a
longitudinal axis, the core
barrel head assembly comprising: an elongate tube body having an outer
surface, an interior
cavity, a proximal end, and a distal end, wherein the elongate tube body
defines at least one
aperture that extends between the interior cavity and the outer surface; and a
valve body that
is movable with respect to the proximal end of the elongate tube along the
longitudinal axis
from a first position to a second position, wherein, when in the second
position, the valve
body causes a greater restriction to flow through the at least one aperture
than when the valve
body is in the first position.
1001041 Aspect 7: The core barrel head assembly of aspect 6,
wherein the at least one
aperture defines a total flow area of less than 0.5 square inches.
[00105] Aspect 8: The core barrel head assembly of aspect 7,
wherein the at least one
aperture has a width dimension along the longitudinal axis that is less than
0.25 inches.
[00106] Aspect 9: The core barrel head assembly of any of
aspects 6-8 wherein the
elongate tube body defines a helical groove that extends radially from the
interior cavity to
the outer surface of the elongate tube body and axially along the longitudinal
axis of the core
barrel head assembly, wherein the helical groove is configured to allow the
elongate tube
body to elastically compress from a neutral length.
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[00107] Aspect 10: The core barrel head assembly of aspect 9,
wherein the valve body
is attached to the distal end of the elongate tube body.
[00108] Aspect 11: The core barrel head assembly of any of
aspects 6-10, further
comprising an electronics compartment having an outer surface, wherein the
electronics
compartment is disposed within the interior cavity of the valve body, wherein
the electronics
compartment is attached to the valve body so that the interior surface of the
interior cavity of
the valve body and the outer surface of the electronics department define a
fluid passage,
wherein the valve body, the electronics compartment, or a combination of at
least one interior
surface of the valve body and at least one exterior surface of the electronics
compartment
defines at least one opening for providing fluid communication between the
fluid passage and
the distal end of the valve body.
[00109] Aspect 12: A method comprising: positioning a drill
string within a borehole,
the drill string having a distal end, wherein the drill string comprises: at
least one drill rod
defining an interior bore, a drill bit at the distal end of the drill string,
and a core barrel head
assembly of any of claims 9-11, wherein the core barrel head assembly has a
distal end and is
disposed within the interior bore of the at least one drill rod, and a core
barrel tube attached to
the distal end of the core barrel head assembly; and receiving a core sample
in the core barrel
tube until the elongate tube body compresses to a length in which the valve
body is in the
second position.
[00110] Aspect 13: The method of aspect 12, further comprising
retracting the drill
string until the elongate tube body expands to a third length that is greater
than the neutral
length.
[00111] Aspect 14: A core barrel head assembly comprising: a
valve body having a
distal end and a proximal end, wherein the valve body defines an interior
cavity having an
interior surface; and an electronics compat __ tment having an outer surface,
wherein the
electronics compartment is disposed within the interior cavity of the valve
body, wherein the
electronics compartment is attached to the valve body so that the interior
surface of the
interior cavity of the valve body and the outer surface of the electronics
department define a
fluid passage, and wherein the valve body, the electronics compartment, or a
combination of
at least one interior surface of the valve body and at least one exterior
surface of the
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electronics compartment defines at least one opening for providing fluid
communication
between the fluid passage and the distal end of the valve body.
[00112] Aspect 15: The core barrel head assembly of aspect 14,
wherein the
electronics compartment houses at least one of a battery or an electronic
orientation
instrument.
[00113] Aspect 16: The core barrel head assembly of aspect 14
or aspect 15, wherein
the fluid passage defined by the interior surface of the interior cavity of'
the valve body and
the outer surface of the electronics department is an annular cavity.
[00114] Aspect 17: The core barrel head assembly of any of
aspects 14-16, wherein the
electronics compartment defines the at least one opening for providing fluid
communication
between the fluid passage and the distal end of the valve body.
[00115] Aspect 18: The core barrel head assembly of aspect 17,
wherein a portion of
the outer surface of the electronics compai __ anent define at least one male
thread along a
threaded length. wherein the inner surface of the valve body defines at least
one
corresponding female thread, wherein the electronics compartment threadedly
couples to the
valve body via the at least one male thread and the at least one corresponding
female thread,
wherein the at least one opening extends through the electronics compartment
along the
threaded length.
[00116] Aspect 19: The core barrel head assembly of aspect 18,
wherein the at least
one opening comprises a plurality of openings separated by respective radially
extending
webs.
[00117] Aspect 20: The core barrel head assembly of any of
aspects 14-16, wherein the
valve body defines the at least one opening for providing fluid communication
between the
fluid passage and the distal end of the valve body.
[00118] Aspect 21: The core barrel head assembly of any of
aspects 14-16, wherein the
combination of at least one interior surface of the valve body and at least
one exterior surface
of the electronics compartment defines the at least one opening for providing
fluid
communication between the fluid passage and the distal end of the valve body.
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[00119] Aspect 22: The core barrel head assembly of any of
aspects 14-21, wherein the
core barrel head assembly comprises a single thrust bearing.
[00120] Aspect 23: The core barrel head assembly of any of
aspects 14-22, wherein the
core barrel head assembly does not comprise a grease port.
[00121] Aspect 24: A core sampling tool, wherein the core
sampling tool comprises
a core barrel and a core barrel head assembly coupled to a proximal end of the
core barrel,
wherein the core barrel head assembly does not comprise a grease port or a
grease fitting.
[00122] Aspect 25: The core sampling tool of aspect 24,
wherein the core barrel
head assembly comprises a spindle and at least one bearing that rotationally
engages the
spindle, wherein the at least one bearing is a self-lubricating bearing.
[00123] Aspect 26: The core sampling tool of aspect 25,
wherein the spindle is a
hollow spindle that defines a bore that extends axially through the spindle.
[00124] Aspect 27: The core sampling tool of aspect 26,
wherein the core barrel
head assembly further comprises a check valve assembly positioned distal of
the hollow
spindle.
[00125] Aspect 28: The core sampling tool of aspect 26,
wherein the core barrel
head assembly further comprises a check valve assembly positioned proximal of
the hollow
spindle.
[00126] Aspect 29: The core sampling tool of aspect 25,
wherein the spindle
comprises a solid spindle that does not define an axial bore extending through
the spindle.
[00127] Aspect 30: The core sampling tool of aspect 29,
wherein the core barrel
head assembly further comprises a check valve assembly positioned distal of
the hollow
spindle.
[00128] Aspect 31: The core sampling tool of aspect 29,
wherein the core barrel
head assembly further comprises a check valve assembly positioned proximal of
the hollow
spindle.
[00129] Aspect 32: A core barrel head assembly configured
for coupling to a core
barrel, the core barrel head assembly comprising: an elongate body having a
proximal end
and a distal end; a bearing subassembly configured to engage the proximal end
of the
elongate body; a spindle subassembly that is rotationally engaged by the
bearing
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subassembly, wherein the spindle subassembly comprises a hollow spindle having
an inner
diameter of at least 5/8 inch, wherein the bearing subassembly comprises one
or more self-
lubricating bearings.
[00130] Aspect 33: The core barrel head assembly of aspect
32, wherein the one or
more self-lubricating bearings are solid oil bearings.
1001311 Aspect 34: The core barrel head assembly of aspect
32 or aspect 33,
wherein the core barrel head assembly does not comprise a grease port or a
grease fitting.
[00132] Aspect 35: The core barrel head assembly of any one
of aspects 32-34,
further comprising a check valve subassembly, wherein the check valve
subassembly engages
the distal end of the elongate body.
[00133] Aspect 36: A method comprising: advancing a core
sampling tool within a
formation, the core sampling tool comprising a core barrel head assembly
coupled to a core
barrel; and receiving core within the core barrel, wherein the method does not
comprise
delivering grease to or within the core barrel head assembly.
[00134] Aspect 37: The method of aspect 36, wherein the core
barrel head assembly
comprises a bearing subassembly and a spindle, wherein the bearing subassembly
comprises
one or more self-lubricating bearings that rotationally engage the spindle.
[00135] Although several embodiments of the invention have been
disclosed in the
foregoing specification, it is understood by those skilled in the art that
many modifications
and other embodiments of the invention will come to mind to which the
invention pertains,
having the benefit of the teaching presented in the foregoing description and
associated
drawings. It is thus understood that the invention is not limited to the
specific embodiments
disclosed hereinabove, and that many modifications and other embodiments are
intended to
be included within the scope of the appended claims. Moreover, although
specific terms are
employed herein, as well as in the claims which follow, they are used only in
a generic and
descriptive sense, and not for the purposes of limiting the described
invention, nor the claims
which follow.
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