U.S. patent application number 15/001715 was filed with the patent office on 2017-07-20 for electric pulse drilling apparatus with hole cleaning passages.
This patent application is currently assigned to BAKER HUGHES INCORPORATED. The applicant listed for this patent is JOERG LEHR. Invention is credited to JOERG LEHR.
Application Number | 20170204668 15/001715 |
Document ID | / |
Family ID | 59314440 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170204668 |
Kind Code |
A1 |
LEHR; JOERG |
July 20, 2017 |
ELECTRIC PULSE DRILLING APPARATUS WITH HOLE CLEANING PASSAGES
Abstract
An electrical pulse cutting device is disclosed that in one
non-limiting embodiment includes a pair of electrodes that generate
electrical pulses inside an object to disintegrate a section of the
object into cuttings, and at least one flow passage in at least one
of the electrodes to provide a passage for a fluid under pressure
to move the cuttings away from the at least one of the
electrodes.
Inventors: |
LEHR; JOERG; (CELLE,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LEHR; JOERG |
CELLE |
|
DE |
|
|
Assignee: |
BAKER HUGHES INCORPORATED
HOUSTON
TX
|
Family ID: |
59314440 |
Appl. No.: |
15/001715 |
Filed: |
January 20, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 7/04 20130101; E21B
44/00 20130101; E21B 47/00 20130101; E21B 7/15 20130101; E21B 47/12
20130101 |
International
Class: |
E21B 7/15 20060101
E21B007/15; E21B 47/12 20060101 E21B047/12; E21B 7/04 20060101
E21B007/04; E21B 44/00 20060101 E21B044/00; E21B 47/00 20060101
E21B047/00 |
Claims
1. An electric pulse cutting device, comprising: a pair of
electrodes that generates electrical pulses inside an object to
disintegrate a section of the object into cuttings; and at least
one flow passage in at least one of the pair of electrodes to
provide a passage for a fluid under pressure to move the cuttings
away from the least one of the electrodes.
2. The electric pulse cutting device of claim 1, wherein the pair
of electrodes are configured to contact the object to pass
electrical energy through a selected depth of the object to
disintegrate the object.
3. The electric pulse cutting device of claim 1 further comprising
a pulse generator that provides electrical energy to the pair of
electrodes at a selected frequency.
4. The electric pulse cutting device of claim 2, wherein the
frequency is less 500 hertz.
5. The electric pulse cutting device of claim 1, wherein the pair
of electrodes includes a ground electrode that is at least
partially outside one of an anode electrode and a cathode electrode
and wherein the at least one fluid passage runs through the ground
electrode.
6. The electric pulse cutting device of claim 5 further comprising
at least one fluid passage through the anode electrode.
7. A drilling apparatus for drilling wellbores, comprising: an
electric pulse cutting device at a bottom end thereof, wherein the
electric pulse device includes: a ground electrode and an anode
electrode for generating electrical pulses inside a rock formation
in a wellbore to disintegrate the rock formation into cuttings; and
at least one fluid flow passage in one of the ground electrode and
the anode electrode to provide a passage for a fluid under pressure
to move the cuttings away from at least one of the ground electrode
and the anode electrode;
8. The drilling apparatus of claim 7 further comprising: a sensor
that provides measurements relating to a downhole parameter of
interest and a controller that adjusts a parameter relating to an
operation of the electric pulse cutting device in response to the
downhole parameter of interest.
9. The drilling apparatus of claim 8, wherein the downhole
parameter of interest is selected from a group consisting of: rate
of penetration of the electric pulse cutting device; vibration
relating to the drilling apparatus; whirl relating to the electric
pulse cutting device; and stick-slip of the electric pulse cutting
device.
10. The drilling apparatus of claim 7, wherein the ground electrode
and the anode electrode are configured to contact the rock
formation to pass electrical energy through a selected depth of the
rock formation to disintegrate the rock formation into
cuttings.
11. The drilling apparatus of claim 7 further comprising a pulse
generator that provides electrical energy to the anode electrode
and the ground electrode at a selected frequency.
12. The drilling apparatus of claim 7, wherein the at least a
portion of the ground electrode is at least partially outside a
portion of the anode electrode and wherein the at least one fluid
flow passage runs through the ground electrode.
13. The drilling apparatus of claim 8, wherein the controller is
located at one of: in a drilling assembly carrying the electric
pulse bit; and at a surface location; and partially in a drilling
assembly carrying the electric pulse bit and partially at a surface
location.
14. The drilling apparatus of claim 7 further comprising a logging
while drilling tool that determines a parameter of interest
relating to formation surrounding the electrical pulse cutting
device.
15. A method of drilling a wellbore, the method comprising:
conveying a drill string into a wellbore that includes an electric
pulse cutting device at a bottom end of a drilling assembly,
wherein the electric pulse cutting device includes a pair of
electrodes and wherein at least one electrode includes a fluid flow
passage therethrough to allow a fluid under pressure to pass
therethrough to move the cuttings away from the at least one
electrodes; disintegrating rock at bottom of the wellbore into
cuttings by generating electrical pulses via the pair of electrodes
inside a selected depth of the rock; and passing the fluid under
pressure through the at least one fluid passage to move the
cuttings away from the at least one of the electrodes during
drilling of the wellbore.
16. The method of claim 15 further comprising determining a
parameter of interest relating to the drill string during drilling
and adjusting a drilling parameter in response to the determined
parameter relating to the drill string.
17. The method of claim 16, wherein the parameter of interest
relating to the drill string is selected from a group consisting
of: vibration; whirl; and stick-slip.
18. The method of claim 16, wherein the drilling parameter is
selected from a group consisting of: rate of penetration; weight on
the electrical pulse cutting device; fluid flow rate; pulse
frequency; temperature; and pressure.
19. The method of claim 15, wherein the pair of electrodes includes
a ground electrode that is at least partially outside one of an
anode electrode and a cathode electrode.
20. The method of claim 19, wherein the fluid flow passage runs
through the ground electrode.
Description
BACKGROUND
[0001] 1. Field of the Disclosure
[0002] The disclosure relates generally to drilling of wellbores
and particularly to electrical impulse cutting apparatus for
drilling such wellbores.
[0003] 2. Background Art
[0004] Wells or wellbores are formed for the production of
hydrocarbons (oil and gas) from subsurface formation zones where
such hydrocarbons are trapped. A drill bit at a bottom end of a
drill string conveyed from a surface location is rotated to cut
through the formation rock to form the wellbores. Commonly used
drill bits include mechanical cutters that penetrate the rock due
to the weight on the bit to disintegrate the rock into small
pieces, referred to as the cuttings or rock cuttings. A drilling
fluid is supplied to the drill string that discharges at the bottom
of the drill bit, which fluid causes the cuttings to flow through
an annulus between the drill sting and wellbore to the surface.
Electrical impulse cutting devices have been proposed as an
alternative to the conventional mechanical drill bits for forming
wellbores. An electrical impulse cutting device utilizes electrodes
to impart high voltage pulses into the rock to generate heat and
pressure inside the rock to disintegrate the rock into cuttings.
Some of the cuttings tend to settle between the electrodes as there
is inadequate or no fluid velocity underneath the electrodes to
move the cuttings away from the electrodes, inhibiting moving of
the cuttings by the drilling fluid to the surface. Therefore, it is
desirable to provide electrical impulse cutting devices and system
that can effectively move the cuttings away from the electrodes to
enable the circulating drilling fluid to move the cuttings to the
surface.
[0005] The disclosure herein provides an electrical impulse cutting
apparatus configured to move to move cuttings away from the
electrodes for effective hole cleaning during drilling of
wellbores.
SUMMARY
[0006] In one aspect, an electrical pulse cutting device is
disclosed that in one non-limiting embodiment includes a pair of
electrodes that generate electrical pulses inside an object to
disintegrate a section of the object into cuttings, and at least
one flow passage in at least one of the electrodes to provide a
passage for a fluid under pressure to move the cuttings away from
the at least one of the electrodes.
[0007] In another aspect, a method of forming a wellbore is
disclosed that in one embodiment includes: conveying a drill string
into a wellbore, wherein the drill string includes an electric
pulse cutting device at a bottom end of a drilling assembly,
wherein the electric pulse cutting device includes a pair of
electrodes and wherein at least one electrode includes a fluid flow
passage therethrough to allow a fluid under pressure to pass
therethrough to move the cuttings away from the at least one of the
electrodes; and disintegrating rock at bottom of the wellbore into
cuttings by generating electrical pulses via the pair of electrodes
within a selected depth of the rock.
[0008] Examples of the certain features of an apparatus and methods
have been summarized rather broadly in order that the detailed
description thereof that follows may be better understood, and in
order that the contributions to the art may be appreciated. There
are, of course, additional features that will be described
hereinafter and which will form the subject of the claims.
DRAWINGS
[0009] For a detailed understanding of the apparatus and methods
disclosed herein, reference should be made to the accompanying
drawings and the detailed description thereof, wherein like
elements are generally given same numerals and wherein:
[0010] FIG. 1 shows a schematic diagram of an exemplary drilling
system that may utilize an embodiment of an electrical pulse drill
bit unit or system disclosed herein for drilling wellbores.
[0011] FIG. 2 shows an electric pulse drill bit system according to
one non-limiting embodiment of the disclosure;
[0012] FIG. 3 shows a cutting device or drill bit according to a
non-limiting embodiment of the disclosure;
[0013] FIG. 4 shows schematic illustration of exemplary electric
field lines generated by an electric pulse cutting device inside a
rock being disintegrated into cuttings and fluid flow passages
through the cutting device to move the cuttings away from the
electrodes, according to one non-limiting embodiment of the
disclosure; and
[0014] FIG. 5 shows a bottom view of an alternative arrangement of
electrodes and fluid flow passage that may be utilized in the
electric pulse drill bit system of FIG. 2.
DETAILED DESCRIPTION
[0015] FIG. 1 is a schematic diagram of an exemplary drilling
system 100 that may utilize an electrical pulse drill bit unit or
system 150 disclosed herein for drilling wellbores. FIG. 1 shows a
wellbore 110 (also referred to as a "borehole" or "well") being
formed in a formation 119 that includes an upper section 111 with a
casing 112 installed therein and a lower section 114 being drilled
with a drill string 118 that includes an electrical pulse drill bit
unit 150. The drill string 118 includes a tubular member 116 that
carries a drilling assembly 130 (also referred to as the
"bottomhole assembly" or "BHA") at its bottom end. The drilling
tubular 116 may be a drill pipe made up by joining pipe sections or
it may be coiled-tubing. An electrical drill bit unit 150 having a
cutting device 155 at an end thereof forms the bottom section of
the BHA 130. The cutting device 155, when activated (as described
later) disintegrates the rock formation 119a at the bottom 110a of
the wellbore 110 to form the wellbore section 114 of a selected
diameter in the formation 119.
[0016] Still referring to FIG. 1, the drill string 118 is shown
conveyed into the wellbore 110 from a rig 180 at the surface 167.
The exemplary rig 180 in FIG. 1 is shown as a land rig for ease of
explanation. The apparatus and methods disclosed herein may also be
utilized with offshore rigs. A rotary table 169 or a top drive 169a
coupled to the drill string 118 may be utilized to rotate the drill
string 118 and the drilling assembly 130. A control unit (also
referred to as a "controller" or "surface controller") 190, which
may be a computer-based unit, at the surface 167 may be utilized
for receiving and processing data transmitted by various sensors
and tools (described later) in the drilling assembly 130 and for
controlling selected operations of the various devices and sensors
in the drilling assembly 130. The surface controller 190 may
include a processor 192, a data storage device (or a
computer-readable medium) 194 for storing data and computer
programs 196 accessible to the processor 192 for determining
various parameters of interest during drilling of the wellbore 110
and for controlling selected operations of the various tools in the
BHA and those of drilling of the wellbore. The data storage device
194 may be any suitable device, including, but not limited to, a
read-only memory (ROM), a random-access memory (RAM), a flash
memory, a magnetic tape, a hard disc and an optical disk. To drill
wellbore 110, a drilling fluid 179 is pumped under pressure into
the tubular member 116 and the drill bit system 150 is activated.
The cutting device 155 disintegrates the rock into cuttings 151.
The drilling fluid 179 discharges at the bottom of the cutting
device 155 and returns to the surface along with the cuttings 151
via the annular space (also referred as the "annulus") 127 between
the drill string 118 and the wellbore 110.
[0017] Still referring to FIG. 1, the drilling assembly 130 may
further include one or more downhole sensors (also referred to as
the measurement-while-drilling (MWD) sensors and
logging-while-drilling (LWD) sensors or tools), collectively
designated by numeral 175, and at least one control unit (or
controller) 170 for processing data received from the sensors 175.
The sensors 175 may include sensors for providing measurements
relating to various drilling parameters, including, but not limited
to, vibration, whirl, stick-slip, flow rate, pressure, temperature,
and weight-on-bit. The drilling assembly further may include
sensors or tools, including, but not limited to, resistivity tool,
acoustic tool, gamma ray tool, nuclear tool and nuclear magnetic
resonance tool. Such sensors and tools are known in the art and are
thus not described herein in detail. The drilling assembly 130 also
includes a power generation device 186 and a suitable telemetry
unit 188, which may utilize any suitable telemetry technique,
including, but not limited to, mud pulse telemetry, electromagnetic
telemetry, acoustic telemetry and wired pipe. Such telemetry
techniques are known in the art and are thus not described herein
in detail. Drilling assembly 130 may further include a steering
device 160 that enables an operator to steer the cutting device 155
in desired directions to drill deviated wellbores. Stabilizers,
such as stabilizers 162 and 164 are provided along the drilling
assembly 130 to stabilize the drilling assembly during drilling of
the wellbore 110. The controller 170 may include a processor 172,
such as a microprocessor, a data storage device 174 and a program
176 for use by the processor to process downhole data and to
communicate data with the surface controller 190 via the two-way
telemetry unit 188. The data storage device may 172 be any suitable
memory device, including, but not limited to, a read-only memory
(ROM), random access memory (RAM), flash memory and disk.
[0018] FIG. 2 is a schematic diagram of an exemplary electric pulse
drill bit unit or system 200 that may be utilized in any suitable
drilling system, including system 100 of FIG. 1. The system 200
includes a cutting device 250 that includes at least a pair of
electrodes 252 that come in contact with the rock or the object to
be disintegrated. The electrodes 252 include an anode electrode or
a cathode electrode 252a and a ground electrode 252b and at least
one fluid flow path 254 through at least one or both the electrodes
252, as explained in more detail in reference to FIGS. 3-5. The
electrodes 252 are activated by a pulse generation system that
includes an electric transformer 210 that supplies power to a
rectifier 220 coupled to a high voltage generator 230, which
supplies the high voltage energy to the anode or cathode electrode
252a. A pulse generator circuit 240 causes the high voltage
generator 230 to provide high voltage pulses to the electrodes 252.
The pulse frequency and voltage may be controlled by controllers
170 and or 190 described in reference to FIG. 1. In various
aspects, the high voltage generator 230 may include multiple stages
and may generate pulses to 600 KV. In one aspect, the pulse
frequency may range between 10 Hz and 20 Hz. In general, the pulse
frequency may be less than 500 Hz. Stabilizers 162 and 164 may be
placed on the system 200. Steering unit 160 also may be placed at a
suitable location in the system 200.
[0019] FIG. 3 shows an electric pulse cutting device 300 (also
referred herein as the "cutting device" or "drill bit") made
according to a non-limiting embodiment of the disclosure. The
cutting device 300 is shown to include a hollow body 310 that
carries an electrode system 320 at its bottom. The electrode system
320 is shown to include a ground electrode 330 that includes an
outer circular member 332 and radial members 332a, 330b and 330c
extending inward from the circular member 332. An anode or a
cathode electrode 340 is shown to include members 340a, 340b and
340c extending outward from the center 350. In the particular
configuration of FIG. 3, the electrode members 340a, 340b and 340c
are inside the circular electrode member 330 and wherein electrode
member 340a is between electrode members 332a and 332b, electrode
member 340b is between electrode members 332b and 332c, while
electrode member 340c is between electrode members 330c and 330a. A
cutting device according to this disclosure may include any number
of fluid flow passages in any suitable configurations through the
electrodes to move the cuttings away from one or more electrode
members when fluid (for example, fluid 179, FIG. 1) flows under
pressure through such passages during drilling of a wellbore to aid
the cuttings to flow to the surface with the fluid. In the
particular configuration of the electrode system 320, the ground
electrode 330 is shown to include a number of flow through passages
345 (such as integrated nozzles). Each such passage receives fluid
179 from fluid flow passages 355 in the body 310. The fluid 179
discharges at the bottom of the electrode system 320 and moves the
cuttings away from one or more electrode members, which process
aids the fluid 179 to carry the cuttings to the surface.
[0020] FIG. 4 shows a schematic diagram 400 of electric field lines
generated by an exemplary electric pulse cutting device made
according to this disclosure inside an object, such as a rock, to
be disintegrated into cuttings 445 and fluid flow passages through
the cutting device that move the cuttings away from one or more
electrodes or electrode members. FIG. 4 shows a pair of electrodes
420 and 430 in contact with an object 410 immersed in a fluid, such
as a drilling fluid 179 (FIG. 1). Electrode 420 includes a fluid
passage 422 that receives the fluid 179 under pressure from a
passage 460 in the body of the cutting device and discharges the
fluid 179 onto the rock 410 in contact with the electrode 420.
Similarly, the electrode 430 includes a fluid passage 432 having an
inlet 432a that receives the fluid 179 from a passage 465 in the
body and discharges the received fluid onto the rock 410. The
electrodes 420 and 430 when excited produce electric field lines
460a in the fluid 179 and lines 460b inside the rock 410. The depth
of the field lines 460b in the rock 410 depends upon the voltage
and the spacing between the electrodes. Electric discharge along
field line 460b produce high temperature plasma resulting pressure
waves inside the rock 410 that disintegrate the rock into cuttings
445. The number of electrode members, their relative positions, the
voltage and the frequency of pulses is selected for optimal
wellbore formation and rate of penetration of the drill bit (150,
FIG. 1) into the formation. It should be noted that any suitable
configuration of the electrodes and flow passages may be utilized
for electrical pulse cutting systems made according to this
disclosure.
[0021] FIG. 5 shows a bottom view of an alternative arrangement of
electrodes 552 of an electric pulse cutting device 500 according to
another non-limiting embodiment of the disclosure. The cutting
device 500 is shown to include ground electrodes 520a, 520b and
520c placed spaced apart along a circle. Anode electrodes or
cathode electrodes 530a, 530b and 530c are also placed spaced apart
along the circle, wherein electrode 530a is between electrode 520a
and 520b, electrode 530b is between electrode 520b and 520c while
electrode 530c is between electrode 520c and 520a. Electrodes 520a,
520b and 520c are shown to include fluid passages 524a, 524b and
524c respectively, while electrodes 530a, 530b and 530c are shown
to include fluid passages 534a, 534b and 534c respectively.
Additionally, electrodes 530a, 530b and 530c are shown to include
insulations 532a, 532b and 532c respectively.
[0022] The foregoing disclosure is directed to the certain
exemplary non-limiting embodiments. Various modifications will be
apparent to those skilled in the art. It is intended that all such
modifications within the scope of the appended claims be embraced
by the foregoing disclosure. The words "comprising" and "comprises"
as used in the claims are to be interpreted to mean "including but
not limited to". Also, the abstract is not to be used to limit the
scope of the claims.
* * * * *