Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
Drill Bit Assembly With a Logging Device
10
BACKGROUND OF THE INVENTION
The present invention relates to the field of downhole oil, gas, and/or
geothermal
exploration and more particularly to the field of drill bits for tool strings
of such
exploration.
Since the beginning of downhole drilling, a lot of time and resources have
been
invested in developing an optimal drill bit for a downhole tool string.
Because of the
enormous expense associated with running a drill rig, the operational quality
of a drill
bit may provide substantial economic benefits.
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Today's drill bits generally serve at least two purposes. Using rotary energy
provided by the tool string they bore through downhole formations, thus
advancing the
tool string further into the ground. They also function to dispense drilling
mud pumped
through the tool string that lubricates parts and washes cuttings and
formation material
to the surface.
The prior art contains references to drill bits with sensors or other
apparatus for
data retrieval. For example, US Patent Number 6,150,822 to Hong, et al
discloses a
microwave frequency range sensor (antenna or wave guide) disposed in the face
of a
diamond or PDC drill bit configured to minimize invasion of drilling fluid
into the
formation ahead of the bit. The sensor is connected to an instrument disposed
in a sub
interposed in the drill stem for generating and measuring the alteration of
microwave
energy.
US Patent Number 6,814,162 to Moran, et al discloses a drill bit, comprising a
bit
body, a sensor disposed in the bit body, a single journal removably mounted to
the bit
body, and a roller cone rotatably mounted to the single journal. The drill bit
may also
comprise a short-hop telemetry transmission device adapted to transmit data
from the
sensor to a measurement-while-drilling device located above the drill bit on
the drill
string.
US Patent Number 6,913,095 to Krueger discloses a closed-loop drilling system
utilizes a bottom hole assembly ("BHA") having a steering assembly having a
rotating
member and a non-rotating sleeve disposed thereon. The sleeve has a plurality
of
expandable force application members that engage a borehole wall. A power
source
and associated electronics for energizing the force application members are
located
outside of the non-rotating sleeve.
BRIEF SUMMARY OF THE INVENTION
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In one aspect of the invention, a drill bit assembly has a body portion
intermediate
a shank portion and a working portion. The working portion has at least one
cutting
element. The drill bit assembly also has a shaft with an end substantially
coaxial to a
central axis of the assembly. The second end of the shaft protrudes from the
working
portion, and at least one downhole logging device is disposed within the
shaft.
The logging device of the drill bit assembly may engage a downhole formation.
The logging device may also be in communication with a downhole network. In
some
embodiments, the drill bit assembly comprises a plurality of logging devices
disposed
within the shaft. At least a portion of the shaft may be electrically isolated
from the
body portion when resistivity or similar parameters are being sensed. The
logging
device may comprise a resistivity sensor, an acoustic sensor, hydrophone, an
annular
pressure sensor, formation pressure sensor, a gamma ray sensor, density
neutron
sensor, a geophone array, or an accelerometer, directional drilling sensor, an
inclination
system that may include a gyroscopic device, a drilling dynamics sensor,
another
system that may be used to evaluate formation properties, an active sensor, a
passive
sensor, a nuclear source, a gamma source, a neutron source, an electrical
source, an
acoustic wave source, a seismic source, a sonic source, or combinations
thereof
In another aspect of the invention, a method of downhole data retrieval
includes
the steps of providing a drill bit assembly having a body portion intermediate
a shank
portion and a working portion and providing a shaft comprising an end
substantially
protruding from the working portion, the shaft having at least one downhole
logging
device. The method includes the additional step of relaying data from the
downhole
logging device to tool string control equipment.
In an additional step, the method may include engaging a downhole formation
with the end of the shaft. The data may be relayed from the downhole logging
device
to the tool string control equipment through a downhole network and/or logged
by a
downhole processing element. The method may also include the step of steering
the
drill bit assembly based on data received from the logging device.
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In still another aspect of the invention, a drill bit assembly has a body
portion
intermediate a shank portion and a working portion. The working portion has at
least
one cutting element. A shaft has a first end disposed within the body portion
and a
second end which is substantially coaxial to a central axis of the assembly.
The second
end of the shaft substantially protrudes from the working portion, and at
least one
downhole logging device is in communication with the shaft.
The shaft of the drill bit assembly may engage a downhole formation. The
downhole logging device may be disposed within the body portion, the working
portion, or another area of a tool string. The sensor may be in communication
with a
downhole network.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a cross-sectional diagram of a drill bit assembly having a shaft
with an energy
source disposed therein.
Fig. 2 is a cross-sectional diagram of a drill bit assembly showing possible
paths of
energy emitted from an energy source.
Fig. 3 is a cross-sectional diagram of a drill bit assembly having an energy
source and
an energy receiver controlled by a downhole processing element.
Fig. 4 is a cross-sectional diagram of a drill bit assembly having an
elongated shaft and
a sensor disposed in the shaft.
Fig. 5 is a cross-sectional diagram of a drill bit assembly having an
elongated shaft and
both an energy source and an energy receiver disposed in the shaft.
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Fig. 6 is a cross-sectional diagram of a drill bit assembly having a shaft
with an
acoustic energy source.
Fig. 7 is a cross-sectional diagram of a drill bit assembly showing possible
paths of
energy emitted at the shaft.
Fig. 8 is a cross-sectional diagram of another drill bit assembly having a
pressure
sensor disposed within a shaft.
Fig. 9 is a cross-sectional diagram of another embodiment of a drill bit
assembly
having acoustic sensors disposed within a shaft.
Fig. 10 is a cross-sectional diagram a drill bit assembly showing possible
paths of
acoustic energy being detected at the shaft.
Fig. 11 is a cross-sectional diagram of another embodiment of a drill bit
assembly
comprising a radioactive energy source in the shaft.
Fig. 12 is a cross-sectional diagram of another embodiment of a drill bit
assembly
comprising a radioactive energy source together with another energy source in
the
shaft.
Fig. 13 is a perspective diagram of one possible data transmission system that
may be
used in conjunction with the present invention.
Fig. 14 is a cross-sectional diagram of a drill bit assembly having energy
sources and
receivers operably connected to a data transmission system.
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,
,
Fig. 15 is a flowchart diagram of a method of downhole data retrieval.
Fig. 16 is a flowchart diagram showing another method of downhole data
retrieval.
DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED
EMBODIMENT
Referring now to Fig. 1, a drill bit assembly 100 comprises a body portion 105
intermediate a working portion 115 and a shank portion 110. The shank portion
110 may
be threaded to allow interconnection with a downhole tool string 160. The
working
portion 115 of the drill bit assembly 100 comprises at least one cutting
element 120 such
as a polycrystalline diamond cutting element.
The drill bit assembly further comprises a shaft 125 having a first end 135
disposed
within the body portion and a second end 130 which is substantially coaxial to
a central
axis 140 of the assembly 100. The second end 130 of the shaft 125
substantially
protrudes from the working portion 115. In some embodiments, of the present
invention,
the shaft may simply be a protrusion formed in the working portion of the
drill bit
assembly. Fluid channels 165 may allow drilling mud or another fluid to pass
through
the drill bit assembly 100.
U.S. Patent No. 7,198,119 and U.S. Patent Publication No. US 2007-0114065 Al
to David Hall, teach many of the mechanical merits of a shaft 125 extending
from the
working portion 115 of the drill bit assembly 100. For example, working in
conjunction
with cutting elements 120, the shaft 125 may help to break up rock formations
and
increase the rate of formation penetration by the drill bit assembly 100. The
shaft 125
may also be used to help steer the assembly 100. In addition to these
mechanical
benefits, considerable data logging benefits may also be realized from the use
of a shaft
125 protruding from the working portion 115 of the drill bit assembly
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100. This is because the shaft 125 may enable measuring certain attributes of
a
downhole formation 155 because of its location and because it physically
engages the
formation 155. The present invention is believed to improve the ability to
take
downhole measurements, such measurements include at least formation
resistivity,
salinity, neutron or sonic porosity, natural gamma, pH, formation density,
formation
pressure, annular pressure, gas, oil or other fluid detection, lithology
identification,
clay analysis, depth, temperature, formation fracture detection, borehole
stability,
formation velocity or slowness, or nuclear magnetic resonance NMR.
The shaft 125 may comprise an energy source 145. The energy source may be
used in conjunction with a corresponding energy receiver 150 located at a
different
point on the drill bit assembly 100 or along the tool string. The energy
source 145 may
be an electric terminal configured to pass a current or a voltage into the
downhole
formation 155 as it engages the downhole formation 155. The electric current
or
voltage may then be received at the corresponding energy receiver 150. By
regulating
the distance between the energy source 145 and the energy receiver 150 and by
applying either the current or voltage between the energy source and the
receiver,
valuable resistivity measurements may be made on the downhole formation 155.
In
some embodiments, the energy source 145 may be electrically isolated from the
energy
receiver 150 by a special dielectric layer 125. In other embodiments it may be
feasible
to electrically isolate the energy source 145 from the energy receiver by
electrically
isolating the energy receiver 150. The energy source 145 and receiver 150 may
function together as a sensor.
In other embodiments, the energy source 145 may be a radioactive source, an
emitting device, an acoustic source, passive source, an active source or
combinations
thereof In other embodiments of the invention, the shaft comprises or is in
communication with a sensor a resistivity sensor system, an acoustic sensor
system,
hydrophone system, an annular pressure sensor system, formation pressure
sensor
system, a gamma ray sensor system, density neutron sensor system, a geophone
array
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system, or an accelerometer system, directional drilling system, an
inclination sensor
system that may include a gyroscopic device, a drilling dynamics system,
another
system that may be used to evaluate formation properties, an active sensor, a
passive
sensor, or combinations thereof
Referring now to Fig. 2, the assembly 100 comprises a shaft 125 with an energy
source 145 disposed in the second end 130 of the shaft. Multiple energy
receivers 150
are disposed along the outer edges of the drill bit assembly 100 and the tool
string 160.
This allows energy emitted from the energy source 145 to be received by the
energy
receivers 150 at varying distances from the energy source 145. By measuring
the
differences among the energy received by the energy receivers 150 calculations
may be
made that characterize the physical properties of the formation 155. In
embodiments
where the energy emitted from the energy source 145 is electrical current, the
path of
current may look similar to the lines 210 shown in Fig. 2.
Although not shown in Fig. 2, a bucking current system may be used to
manipulate the path electric energy travels. For example the bucking current
system
may be disposed between the energy source 145 and the at least one receiver
150. A
bucking current system may comprise of an additional electric energy source
and
receiver. The energy passed from the additional electric source to the
receiver of the
bucking system may repel the energy traveling from energy source 145, forcing
the
energy to travel deeper into the formation which allows measurements further
away
from drill bit assembly to be taken. In other embodiments, a bucking current
system
may be used to confine the travel of the energy to a path closer to the drill
bit assembly.
Referring now to Fig. 3, an energy source 145 and energy receivers 150 may be
in
communication with a local processing element 305. The processing element 305
may
provide the electrical potential between the energy source 145 and the
receivers 150
and log measurements taken as data. These data may then be routed to downhole
tool
string control equipment or to surface equipment to be interpreted. Once
interpreted,
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the drill bit assembly 100 may be controlled according to information provided
by the
measurements.
Referring now to Fig. 4, another embodiment of a drill bit assembly 100 is
shown.
In this embodiment, the drill bit assembly comprises a shaft 125 that
protrudes
substantially from the working portion 115 of the assembly 100. This type of
shaft 125
may be used in directional drilling applications that require steering the
drill bit
assembly 100 during drilling operations. While the shaft 125 is generally
coaxial to the
central axis 140 of the assembly, steering elements 415 may be used to
position the
shaft 125 in such a way that a desired trajectory may be followed by the tool
string 160
during drilling. In some embodiments, the shaft may comprise an asymmetric
geometry which is adapted to rotate independent of the body portion of the
drill bit
assembly. A brake system may be incorporated into the drill bit assembly or in
a
downhole tool string component attached to the drill bit assembly. The brake
may be
adapted to position the asymmetric geometry of the shaft in such a manner as
to cause
the drill string to travel along a predetermined trajectory. Once the shaft is
correctly
positioned, the brake may release the shaft which, due to the weight of the
tool string
loaded to it, will rotationally fix against the formation while the drill bit
assembly
rotates around the shaft.
In this embodiment, the shaft 125 comprises a sensor 405. While the sensor 405
shown is an induction-type resistivity sensor, in other embodiments the sensor
405 may
be a laterolog resistivity sensor, a short normal resistivity sensor, an
electromagnetic
wave resistivity tool, a nuclear sensor, an acoustic sensor, or a pressure
sensor. It is
believed that an elongated shaft 125 as shown in this figure may substantially
engage
the downhole formation 155 and provide data that more accurately represents
the
characteristics of the formation 155 being drilled.
Referring now to Fig. 5, a drill bit assembly 100 mechanically similar to that
of
Fig. 4 is shown with the shaft 125 comprising both an energy source 145 and a
corresponding energy receiver 150. One or both of the energy source 145 and
the
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energy receiver 150 may be electrically isolated from the other with
insulative material
505.
One advantage of such a configuration is that under circumstances in which the
shaft 125 engages a downhole formation, the energy emitted from the energy
source
145 almost entirely passes through the formation 155 and minimize interference
from
drilling fluids and other materials used in drilling. The energy source 145
may also be
used in conjunction with additional receivers 150 situated further up the
downhole tool
string 160.
Referring now to Fig. 6, seismic and sonic measurements may provide very
useful
information about the composition of downhole formations 155. For this reason,
a
shaft 125 in the downhole assembly may comprise an energy source 145 that
produces
acoustic energy. In the embodiment shown, the energy source 145 is a
piezoelectric
device in communication with the shaft 125. The piezoelectric device is
adapted to
create and pass an acoustic signal through the shaft 125 and into the downhole
formation 155, after which reflected portions of the acoustic signal may be
received by
energy receivers 150 disposed along the tool string 160 or positioned at
surface.
Preferably, the acoustic source is adapted to produce a signal comprising
multiple
frequencies. The acoustic energy source 145 may be in communication with
downhole
and/or surface control equipment which provide an electrical signal which is
converted
into the acoustic signal. Such sources may comprise piezoelectric or
magnetostrictive
elements. The control equipment may be in communication with the source
through
electrically conductive medium. For example, a coaxial cable, wire, twisted
pair of
wires or combinations thereof may be secured within both the drill bit
assembly and at
least a downhole tool string component connected to the drill bit assembly.
The
medium may be in inductive or electrical communication with each other through
couplers 615 positioned so as to allow signal transmission across the
connection of the
downhole component and the drill bit assembly. The couplers may be disposed
within
recesses in either primary or secondary shoulder of the connection or they may
be
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disposed within inserts positioned within the bores of the drill bit assembly
and the
downhole tool string component. In other embodiments, acoustic energy may be
emitted from the shaft 125 using hydraulic or other mechanical means.
The embodiment shown in Fig. 6 may improve drilling dynamics by stabilizing
the drill bit assembly and also helping to control the weight loaded to the
working
portion. The shaft 125 may be controlled hydraulically, electrically, or
mechanically to
move vertically with respect to the drill bit assembly 100. A shock absorbing
spring
605 and bearings 610 may also aid in the mechanical functionality of the shaft
125.
The embodiment of in Fig 6 may also be operated in a passive mode where
vibrations, shocks caused by drilling or some other acoustic energy source
(such as
from the surface or a cross well operation) may vibrate the shaft. Such
vibrations may
be converted by a piezoelectric or magnetostrictive element into electric
signals.
These signal may provide information about the physical properties of the
rocks ahead
of, around or above the working portion.
Referring now to Fig. 7, acoustic waves 701 emitted from the shaft 125 are
shown
reaching an acoustic impedance boundary 705. Acoustic impedance boundaries 705
may be a result from a feature in the formation such as a fault, a salt body,
change in
formation hardness, change in formation material, a hydrocarbon formation, or
other
changes in the formation. Acoustic waves reflect off of such acoustic
impedance
boundaries 705 and may be sensed by energy receivers 150 at the surface, in
the tool
string 160, the drill bit assembly and/or in the shaft. Physical attributes of
acoustic
boundaries 705 such as its spatial location and dimensional or surface
attributes,
acoustic properties and composition may be realized by interpreting the waves
received
by the energy receivers 150. These attributes may then be used to direct the
tool string
160 in the most beneficial manner with respect to the acoustic boundaries 705.
Although not shown in Fig. 7, an acoustic wave may be produced at the surface
or at
another location on the tool string and reflect off of the acoustic impedance
boundary
and be received by energy receivers in the shaft
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Referring now to Fig. 8, the drill bit assembly 100 may comprise a pressure
sensor
adapted to measure the compressive strength of the formation 805. The pressure
sensor 805 may be in communication with the shaft 125 or be disposed within
the
shaft. In this particular embodiment, a high strength formation 155 is being
penetrated
by the drill bit assembly 100 and the strength of the formation 155 causes the
shaft 125
to be pushed up into the drill bit assembly 100 and compress the spring 605.
The
spring 605 may be fairly resilient such that a significant amount of pressure
may be
required to compress it. The sensor 805 shown is a position sensor that may
sense the
position of the shaft 125. Such a sensor may include magnets, hall-effect
elements,
piezoelectric elements, magnetostrictive elements, capacitive elements or
combinations
thereof. In this embodiment, the position of the shaft 125 may be indicative
of the
pressure of the formation 155. The sensor 805 may track the position of the
shaft 125,
but in some embodiments a small tracking device 810 on the shaft 125 may
provide
more accurate measurements. In some embodiments, a strain sensor may used to
measure the strain in the shaft, spring, or both.
Referring now to Fig. 9, sensors 405 disposed within the shaft of a drill bit
assembly 100 may be acoustic sensors such as geophones. Acoustic sensors may
be
particularly useful for seismic and sonic wave measurements. In some
embodiments,
an acoustic source may generate a great deal of acoustic energy at the surface
of the
earth. The acoustic energy then propagates through the earth until it reaches
the
acoustic sensors. As the waveform of the acoustic energy received at the
various
sensors 405 may be indicative of the physical characteristics of the formation
155
being drilled, it may be particularly useful to have acoustic sensors disposed
in the
shaft 125 that engages the downhole formation 155. Sensors may not be limited
to
being positioned in the shaft but may additionally be positioned elsewhere on
the tool
string as part an array.
In other embodiments an acoustic signal may be generated downhole through
acoustic sources disposed in the drill bit assembly 100 or other locations on
the tool
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string 160. The acoustic signal may also come from another well bore, or in
some
embodiments, the acoustic signal may be generated by the vibrations in the
earth
generated as the drill bit assembly advances in the earth. In yet another
embodiment,
the acoustic signal may be generated by the process of pressurizing and
fracturing the
formation along weakness in the formation. In such an embodiment, the bore
hole may
be pressurized to an extent that the formation breaks at its weakest points.
The
vibrations generated by the fracturing of the formation may be recorded by the
sensors
405. The sensors 405 may be in communication with a local storage module 905
that
may log their data and/or provide them with electrical power. The control
module 905
may communicate with tool string control equipment to assist in planning the
trajectory
of the tool string 160.
Fig. 10 shows a cross-sectional view of the drill bit assembly with acoustic
waves
1005 reflected off of an acoustic impedance boundary 705 that is ahead of or
otherwise
proximal to the bit and being received by the sensors 405 in the shaft, along
the tool
string, or at the surface. In other embodiments of the invention, sensors 405
may sense
gamma rays, radioactive energy, resistivity, torque, pressure, or other
drilling dynamics
measurements or combinations thereof from the downhole formation 155 being
drilled.
Referring now to Fig. 11, in some embodiments of the invention, it may be
beneficial for a drill bit assembly 100 to comprise a shaft 125 with an energy
source
145 that is radioactive or emits subatomic particles. Examples of such sources
include
active gamma sources and neutron sources. At least one energy receiver 150 may
be
disposed within the drill bit assembly 100 and receive the radioactive energy
or
subatomic particles that are transmitted through the downhole formation 155.
In some
embodiments of the invention, the energy source may be disposed within the
drill bit
assembly, tool string, or at the surface and the sensor is disposed in or in
communication with the shaft. In some embodiments, the gamma source may be
cesium 137. The neutron source may comprise an Americium Beryllium source or
it
may comprise a pulsed neutron generator which uses deuterium and/or tritium
ions. In
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other embodiments, the gamma or neutron source may be disposed within the body
of the drill bit assembly.
Referring now to Fig. 12, the drill bit assembly 100 may comprise multiple
energy
sources 145 in the shaft 125. For example, the shaft 125 may comprise a gamma
ray
source in addition to an electrical current source. Corresponding energy
receivers 150
may work in conjunction with the energy sources 145 to provide gamma and
resistivity
measurements, respectively.
A drill bit assembly 100 according to the present invention may be in
communication with one or more tools in a network. Referring now to Fig.
13, a downhole network 1300 may comprise one or more downhole tool string
components 1305 linked together in a tool string 160 and in communication with
surface equipment 1303. Data may be transmitted up and down the tool string
160 and
between different tool components 1305.
The tool string 160 may be suspended by a derrick 1301. Data may be
transmitted
along the tool string 160 through techniques known in the art. A preferred
method of
downhole data transmission using inductive couplers disposed in tool joints is
disclosed
in the U.S. Patent 6,670,880 to Hall, et al. An alternate data transmission
path may
comprise direct electrical contacts in tool joints such as in the system
disclosed in U.S.
Patent 6,688,396 to Floerke, et al. Another data transmission system that may
also be
adapted for use with the present invention is disclosed in U.S. Patent
6,641,434 to
Boyle, et al. In some embodiments, of the present invention alternative forms
of
telemetry may be used to communicate with the drill bit assembly, such as
telemetry
systems that communicate through the drilling mud or through the earth. Such
telemetry
systems may use electromagnetic of acoustic waves. The alternative forms of
telemetry
may be the primary telemetry system for
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communication with the drill bit assembly or they may be back-up systems
designed to
maintain some communication if the primary telemetry system fails.
A data swivel 1302, or a wireless top-hole data connection may facilitate the
transfer of data between the rotatable tool string 160 and the stationary
surface
equipment 1303. Downhole tool string components 1305 may comprise drill pipes,
jars, shock absorbers, mud hammers, air hammers, mud motors, turbines,
reamers,
under-reamers, fishing tools, steering elements, MWD tools, LWD tools, seismic
sources, seismic receivers, pumps, perforators, packers, other tools with an
explosive
charge, and mud-pulse sirens.
Having a network 1300 in the tool string 160 may enable high-speed
communication between each device connected to it and facilitate the
transmission and
receipt of data between sensors 405, energy sources 145, and energy receivers
150 in
the shaft 125 of the drill bit assembly 100.
Referring now to Fig. 14, a drill bit assembly 100 with an energy source 145,
energy receivers 150, and sensors 405 designed to operate in a downhole
network 1300
is shown. The energy source 145 and sensors 405 are disposed within the shaft
125. A
processing element 305 may control the energy source 145, their corresponding
energy
receivers 150, and the sensors 405. The processing element 305 may also serve
to log
data received or interpret measurements from the energy receivers 150 or the
sensors
405. The processing element 305 may be in communication with the downhole
network 1300 through a system of inductive couplers 615 and coaxial cable 1403
disposed within the tool string 160 as has been previously discussed.
Referring now to Fig. 15, a method 1500 of downhole data retrieval comprises
the
steps of providing 1505 a drill bit assembly having a body portion
intermediate a shank
portion and a working portion, providing 1510 a shaft comprising an end
substantially
protruding from the working portion, the shaft having at least one sensor, and
relaying
1515 data from the sensor to tool string control equipment.
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The method 1500 may include the step of engaging a downhole formation with
the end of the shaft. This may provide optimal measurements and/or data from
the
sensor disposed within the shaft. The data may be relayed 1515 from the sensor
to tool
string control equipment such as downhole intelligent steering equipment or
surface
control equipment through a downhole network. The tool string control
equipment
may then change drilling parameters according to the data received to optimize
drilling
efficiency. For example, the drill bit assembly may be steered according to
data
received from the sensor.
The data may also be logged in a local storage module for later retrieval or
delayed transmission to tool string control equipment.
Referring now to Fig. 16, another method 1600 of downhole data retrieval
comprises the steps of providing 1605 a drill bit assembly having a body
portion
intermediate a shank portion and a working portion, providing 1610 a shaft
comprising
an end substantially protruding from the working portion, the shaft having at
least one
energy source, emitting 1615 energy from the energy source into a formation
and
receiving 1620 at least a portion of the emitted energy downhole in a downhole
tool.
The method 1600 may also include the step of engaging a downhole formation
with the end of the shaft. The portion of the emitted energy received 1620 in
the
downhole tool may be used to sense parameters of the formation, such as
resistivity,
composition, physical dimensions, and other properties. The portion of emitted
energy
received 1620 may also be logged as data and be stored in a local storage
module such
as a processing element. Other properties of the energy received 1620 may also
be
logged as data such as distortions or transformations in waveforms.
The data may be sent to tool string control equipment through a downhole
network. As in the method 1500 of Fig. 16, the tool string control equipment
may then
change drilling parameters according to the data received to optimize drilling
efficiency. The method 1600 may include the step of steering the drill bit
assembly
based on the data.
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Whereas the present invention has been described in particular relation to the
drawings attached hereto, it should be understood that other and further
modifications
apart from those shown or suggested herein, may be made within the scope and
spirit
of the present invention.
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