U.S. patent application number 15/887607 was filed with the patent office on 2019-08-08 for deepset receiver for drilling application.
The applicant listed for this patent is Nabors Drilling Technologies USA, Inc.. Invention is credited to Harmeet Kaur.
Application Number | 20190242245 15/887607 |
Document ID | / |
Family ID | 67476090 |
Filed Date | 2019-08-08 |
United States Patent
Application |
20190242245 |
Kind Code |
A1 |
Kaur; Harmeet |
August 8, 2019 |
DEEPSET RECEIVER FOR DRILLING APPLICATION
Abstract
Drilling telemetry systems and methods include a cable antenna a
cable antenna in an auxiliary borehole in a subterranean formation
arranged to receive electromagnetic signal transmitted from an EM
tool in an adjacent wellbore in the subterranean formation. The
cable antenna may include a wireline cable having a center core, an
insulated electrical cable head in direct electrical communication
with the center core, and an uninsulated signal receiver in direct
electrical communication with electrical cable head. The
uninsulated signal receiver may have an outer surface formed of a
conductive material and configured to contact a natural
subterranean formation.
Inventors: |
Kaur; Harmeet; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nabors Drilling Technologies USA, Inc. |
Houston |
TX |
US |
|
|
Family ID: |
67476090 |
Appl. No.: |
15/887607 |
Filed: |
February 2, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 47/125 20200501;
E21B 47/092 20200501; E21B 17/023 20130101; E21B 47/10 20130101;
E21B 47/13 20200501 |
International
Class: |
E21B 47/12 20060101
E21B047/12; E21B 17/02 20060101 E21B017/02 |
Claims
1. A drilling telemetry system comprising: an EM tool sized and
configured to be disposed on a drill string and introduced into a
wellbore in a subterranean formation, the EM tool comprising a
transmitter configured to transmit an electromagnetic signal
through the subterranean formation; and a cable antenna sized and
configured to be introduced into an adjacent auxiliary borehole in
the subterranean formation and arranged to receive the
electromagnetic signal transmitted from the EM tool, the cable
antenna comprising a wireline cable having a center core, an
electrical cable head in direct electrical communication and
extending around a distal-most portion of the center core, and an
uninsulated signal receiver at a distal-most end of the electrical
cable head, the uninsulated signal receiver in direct electrical
communication with the electrical cable head, the uninsulated
signal receiver having an outer surface formed of a conductive
material and configured to engage against a natural subterranean
formation.
2. The drilling telemetry system of claim 1, wherein the
uninsulated signal receiver has a teardrop shape forming a bulbous
head.
3. The drilling telemetry system of claim 1, wherein the
uninsulated signal receiver comprises a threaded cavity formed
therein for receiving a portion of the electrical cable head.
4. The drilling telemetry system of claim 1, wherein the cable
antenna comprises a polymeric jacket around the center core, and a
protective layer disposed around the polymeric jacket.
5. The drilling telemetry system of claim 4, wherein the protective
layer is embedded within and fixedly attaches the electrical cable
head to the wireline cable.
6. The drilling telemetry system of claim 1, wherein the conductive
material of the uninsulated signal receiver comprises stainless
steel.
7. The drilling telemetry system of claim 1, wherein the EM tool
comprises a transmitter and a power source.
8. The drilling telemetry system of claim 1, wherein the
uninsulated signal receiver has a diameter of about 2 to about 12
inches, and a length of about 3 to about 18 inches.
9. A method of using a drilling telemetry system comprising:
introducing an EM tool to a wellbore; introducing a signal
receiving system to an adjacent auxiliary borehole; transmitting an
EM signal from the EM tool in the wellbore; detecting the
transmitted EM signal with a signal receiver having a conductive
exterior surface in direct contact with walls of the auxiliary
borehole, the conductive exterior surface being in direct
electrical communication with a distal-most end of an electrical
cable head, the electrical cable head being in direct electrical
communication with a distal-most end of a wireline cable; and
communicating the detected EM signal to a signal processing system
in communication with the wireline cable.
10. The method of claim 9, wherein detecting the transmitted EM
signal with the signal receiver comprises detecting the transmitted
EM signal only at the signal receiver.
11. The method of claim 9, comprising performing a drilling
operation, and wherein transmitting the EM signal from the EM tool
occurs during the drilling operation.
12. The method of claim 9, comprising insulating or isolating a
conductive center core in the wireline cable and a conductor in the
electrical cable head from contact with the walls of the auxiliary
borehole.
13. The method of claim 9, wherein communicating the detected EM
signal comprises communicating the detected EM signal through a
conductor in the electrical cable head and through a conductive
center core of the wireline cable.
14. The method of claim 9, wherein the exterior surface of the
signal receiver is in direct conductive electrical communication
with a conductor in the electrical cable head.
15. The method of claim 9, comprising threading the signal receiver
on to a distal end of the electrical cable head to place a
spring-loaded contact in electrical communication with the signal
receiver.
16. The method of claim 9, wherein the signal receiver has a
teardrop shape forming a bulbous head.
17. The method of claim 9, wherein transmitting an EM signal
comprises transmitting an EM signal representative of one or more
detected parameters of the wellbore, an environment surrounding the
wellbore, of drilling equipment, of a subterranean formation, or a
combination thereof.
18. A drilling telemetry system comprising: an EM tool sized and
configured to be disposed on a drill string and introduced into a
wellbore in a subterranean formation, the EM tool comprising a
transmitter configured to transmit an electromagnetic signal
through the subterranean formation; and a cable antenna sized and
configured to be introduced into an adjacent auxiliary borehole in
the subterranean formation and to receive the electromagnetic
signal transmitted from the EM tool, the cable antenna comprising:
a wireline cable having a center core, a polymeric insulative layer
disposed about the center core, and an outer protective layer
disposed about the polymeric insulative layer; an electrical cable
head having a housing, an electrical conductor in electrical
communication with the center core of the wireline cable and
extending through the housing, and a cable anchor attached to the
outer protective layer and configured to secure the electrical
cable head to a distal-most end of the wireline cable, the housing
having a distal end having a spring-loaded contact; and an
uninsulated signal receiver disposed at a distal-most end of the
cable antenna and formed of a rigid, conductive material having a
diameter of about 2 to about 12 inches, the uninsulated signal
receiver having a conductive outer surface exposed to engage
against a natural subterranean formation when the cable antenna is
disposed in borehole, the uninsulated signal receiver being in
direct electrical communication with the spring-loaded contact to
provide uninterrupted electrical communication between the
conductive outer surface and the electrical conductor of the
electrical cable head.
19. The drilling telemetry system of claim 18, wherein the
uninsulated signal receiver has a teardrop shape forming a bulbous
head.
20. The drilling telemetry system of claim 18, wherein the
uninsulated signal receiver comprises a threaded cavity formed
therein for receiving a portion of the electrical cable head.
Description
BACKGROUND OF THE DISCLOSURE
[0001] The present disclosure relates in general to logging tools
and particularly to receivers used in electromagnetic logging
tools.
[0002] Measurement-while-drilling (MWD) tools and
logging-while-drilling (LWD) tools capture information during the
process of drilling a wellbore. However, the ability of current
receivers to receive signals using MWD tools typically provide
drilling parameter information such as weight on the bit, torque,
temperature, pressure, direction, and inclination. LWD tools
typically provide formation evaluation measurements such as
resistivity, porosity, and NMR distributions (e.g., T1 and T2). MWD
and LWD tools often have characteristics common to wireline tools
(e.g., transmitting and receiving antennas), but MWD and LWD tools
must be constructed to not only endure but to operate in the harsh
environment of drilling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The present disclosure is best understood from the following
detailed description when read with the accompanying figures. It is
emphasized that, in accordance with the standard practice in the
industry, various features are not drawn to scale. In fact, the
dimensions of the various features may be arbitrarily increased or
reduced for clarity of discussion.
[0004] FIG. 1 is an illustration of an exemplary drilling telemetry
system in a subterranean formation according to one or more aspects
of the present disclosure.
[0005] FIG. 2 is an illustration of a cross-sectional view of an
exemplary electromagnetic tool of the telemetry system of FIG. 1
according to one or more aspects of the present disclosure.
[0006] FIG. 3 is an illustration of a cross-sectional view
exemplary signal receiving system of the telemetry system of FIG. 1
according to one or more aspects of the present disclosure.
[0007] FIG. 4 is an illustration of a perspective view of the
exemplary signal receiver according to one or more aspects of the
present disclosure.
[0008] FIG. 5 is a flow chart diagram of at least a portion of a
method according to one or more aspects of the present
disclosure.
DETAILED DESCRIPTION
[0009] It is to be understood that the following disclosure
provides many different embodiments, or examples, for implementing
different features of various embodiments. Specific examples of
components and arrangements are described below to simplify the
present disclosure. These are, of course, merely examples and are
not intended to be limiting. In addition, the present disclosure
may repeat reference numerals and/or letters in the various
examples. This repetition is for the purpose of simplicity and
clarity and does not in itself dictate a relationship between the
various embodiments and/or configurations discussed. Moreover, the
formation of a first feature over or on a second feature in the
description that follows may include embodiments in which the first
and second features are formed in direct contact, and may also
include embodiments in which additional features may be formed
interposing the first and second features, such that the first and
second features may not be in direct contact.
[0010] This disclosure is directed to an improved system and method
for obtaining downhole information during a well drilling process.
In some implementations, the system and method employ a
transmitting element on a drill string that communicates
electromagnetic signals through subterranean formations to a
receiver disposed in a separate auxiliary borehole. The receiver
may be particularly arranged to detect and receive signals, even
weak signals, passed through the subterranean formation. In this
implementation, the receiver is particularly designed without
exterior material that may insulate or dampen signals that may be
received through the subterranean formation. That is, in some
exemplary implementations, the receiver comprises a conductive
material forming an external surface of the receiver and disposed
in direct contact with the subterranean formation. In addition, the
conductive material may be in direct communication with a center
core or wire forming a portion of the wireline cable. Signal
processing may occur at the surface.
[0011] FIG. 1 shows an example of a drilling telemetry system 100
for signaling in a subterranean formation. In this implementation,
the drilling telemetry system 100 is formed of a drilling rig
system 102 and a signal receiving system 104. The drilling rig
system 102 includes, among other components, a transmitter, and the
signal receiving system 104 includes, among other components, a
receiver. The drilling rig system 102 may electromagnetically
communicate information to the receiving system 104. For example,
the drilling rig system 102 may transmit information, such as
information relating to the status of the drilling rig system 102,
the wellbore, or other information to the receiving system 104. In
other examples, the drilling rig system 102 may emit
electromagnetic signals that may be captured by the receiving
system 104 that may allow the receiving system 104 to detect
geological formation characteristics or other information relating
to the geographic material through which the signals are
transmitted.
[0012] The drilling rig system 102 may be, for example, a
land-based drilling rig system--however, one or more aspects of the
present disclosure are applicable or readily adaptable to any type
of drilling rig system (e.g., a jack-up rig, a semisubmersible, a
drill ship, a coiled tubing rig, a well service rig adapted for
drilling and/or re-entry operations, and a casing drilling rig,
among others). The drilling rig system 102 includes a mast 106 that
supports lifting gear above a rig floor 108, which lifting gear may
include a crown block and a traveling block. The crown block may be
disposed at or near the top of the mast 106. The traveling block
may hang from the crown block by a drilling line. The drilling line
may extend at one end from the lifting gear to drawworks, which
drawworks are configured to reel out and reel in the drilling line
to cause the traveling block to be lowered and raised relative to
the rig floor 108.
[0013] In some implementations, the drilling rig system 102 may
include a top drive 110 suspended from the bottom of the traveling
block. A drill string 112 may be suspended from the top drive 110
and suspended within a wellbore 113.
[0014] The drill string 112 may include interconnected sections of
drill pipe 114, a bottom-hole assembly ("BHA") 116, and a drill bit
118. The BHA 116 may include stabilizers, drill collars, and/or
measurement-while-drilling ("MWD") or wireline conveyed
instruments, among other components. The drill bit 118 (also be
referred to herein as a tool) is connected to the bottom of the BHA
116 or is otherwise attached to the drill string 112.
[0015] The downhole MWD or wireline conveyed instruments may be
configured for the evaluation of physical properties such as
pressure, temperature, torque, weight-on-bit ("WOB"), vibration,
inclination, azimuth, toolface orientation in three-dimensional
space, and/or other downhole parameters. These measurements may be
made downhole, stored in solid-state memory for some time, and
downloaded from the instrument(s) at the surface and/or transmitted
real-time to the surface. In the implementations described herein,
data may be transmitted electromagnetic pulses. In some
implementations, in addition to transmission capability, the MWD
tools and/or other portions of the BHA 116 may have the ability to
store measurements for later retrieval via wireline and/or when the
BHA 116 is tripped out of the wellbore 113.
[0016] In the embodiment of FIG. 1, the top drive 110 is utilized
to impart rotary motion to the drill string 112. However, aspects
of the present disclosure are also applicable or readily adaptable
to implementations utilizing other drive systems, such as a power
swivel, a rotary table, a coiled tubing unit, a downhole motor,
and/or a conventional rotary rig, among others.
[0017] The drilling rig system 102 also includes a control system
120 configured to control or assist in the control of one or more
components of the drilling rig system 102--for example, the control
system 120 may be configured to transmit operational control
signals to a drawworks, the top drive 110, the BHA 116 and/or
additional equipment. In some embodiments, the control system 120
includes one or more systems located in a control room proximate
the drilling rig system 102, such as the general purpose shelter
often referred to as the "doghouse" serving as a combination tool
shed, office, communications center, and general meeting place. The
control system 120 may be configured to transmit the operational
control signals to the drawworks, the top drive 110, the BHA 116,
and/or other equipment via wired or wireless transmission (not
shown). The control system 120 may also be configured to receive
electronic signals via wired or wireless transmission (also not
shown) from a variety of sensors included in the drilling rig
system 102, where each sensor is configured to detect an
operational characteristic or parameter. Some example sensors from
which the control system 120 is configured to receive electronic
signals via wired or wireless transmission (not shown) may include
one or more of the following: a torque sensor, a speed sensor, and
a WOB sensor. In some implementations, the BHA 116 may also include
sensors disposed thereon. Some exemplary sensors include for
example, a downhole annular pressure sensor 122a, a shock/vibration
sensor 122b, a toolface sensor 122c, a WOB sensor 122d, a surface
casing annular pressure sensor 124, a mud motor delta pressure
(".DELTA.P") sensor 126a, and one or more torque sensors 126b. The
sensors are merely examples of any of a variety of sensors that may
be included on the BHA 116, the drill bit 118, and/or otherwise
disposed about the drilling rig system 102.
[0018] In this exemplary embodiment, the BHA 116 also includes an
EM tool 130. The EM tool 130 may be configured to propagate an
electromagnetic signal to convey information from the BHA for
receipt and analysis by drilling rig personnel. Although identified
as a part of the BHA 116, in some implementations, the EM tool 130
is disposed elsewhere along the drill string 112 and down in the
wellbore 113. Some implementations include multiple EM tools 130
arranged to propagate a signal through the subterranean formations.
The EM tool 130 may form a part of the measurement while drilling
MWD tool. In some implementations, the EM tool 130 may form a part
of a collar or stabilizer of the drill string. Some implementations
of the EM tool 130 feature 2-way EM communication, while other
implementations include only transmission capability. In some
implementations, the power, the data rate, and the carrier wave may
be adjustable while drilling to help transmit through changing
formations. In some implementations, the EM tool may operate using
batteries or a turbine alternator. The turbine alternator may
enable longer downhole times, and higher transmitting power for
longer periods. Some implementations may include backup batteries
for operation during periods of no flow.
[0019] FIG. 2 shows an example of an EM tool 130 that may form a
part of the BHA 116. The EM tool 130 may include an electrode 131,
a downlink receiver 132, a transmitter 133, and the power source
134, such as batteries. The electrode 131 may enable the EM tool
130 to communicate with other downhole systems such as, for
example, sensing systems that may be carried on the BHA. The
downlink receiver 132 may be configured to receive signals and
information from the surface, from other EM tools, or other
equipment that may be in communication with the EM tool 130. The
transmitter 133 transmits EM signals through geological formations.
In some implementations, the transmitter 133 is a high-voltage
transmitter configured to automatically select the necessary power
usage for the formation resistance. This may help extend the life
of the power source 134 by reducing the need to transmit at full
power in certain situations.
[0020] Returning to FIG. 1, the signal receiving system 104 may be
disposed in an auxiliary borehole 138. The signal receiving system
104 may include a cable antenna 140 and a signal processing system
142. In the implementation shown, the cable antenna 140 includes a
wireline cable 144, an electrical cable head 146, and a signal
receiver 148. In this example, the wireline cable 144 may extend or
be wound around a cable coil or reel 150 disposed on steerable
equipment, such as a working vehicle 152, such as a truck. In the
deployed configuration shown, the wireline cable 144 may extend
from the cable coil 150 through a bore head 154, and into the
auxiliary borehole 138.
[0021] FIG. 3 shows a cross-section of a portion of the signal
receiving system 104, including a portion of the wireline cable
144, the electrical cable head 146, and the signal receiver 148.
The wireline cable 144 may include a center core 160, a polymer
jacket 162 surrounding the center core 160, and a protective or
armor layer 164 disposed about the polymer jacket 162. The center
core 160 may be formed of a conductive material and may extend the
length of the wireline cable 144. The center core 160 may be
configured to communicate signals from the electrical cable head
146 and the signal receiver 148 to the processing system 142. In
some examples, the polymer jacket is a polytetrafluoroethylene
(PTFE) material, and in some implementations, the polymer jacket is
or includes TEFLON.RTM. material. The polymer jacket 162 may
insulate or isolate the center core 160 from the armor layer 164.
The protective or armor layer 164 may be formed of any material
that provides protection and strength to the wireline cable 144.
For example, it may comprise a metal or metal-clad, hollow cable
that provides sufficient tensile strength to the wireline cable
144. It may be formed of a plurality of braided wires or otherwise
formed. It may be metal or some other material, including
non-conductive materials. It may be designed to carry the weight of
electrical cable head 146 and the signal receiver 148. The armor
layer 164 may form the outer surface of the wireline cable 144. In
some implementations, the armor layer is a steel armor layer.
[0022] The electrical cable head 146 may be disposed between the
wireline cable 144 and the signal receiver 148. It may electrically
connect the center core 160 to the conductive material of the
signal receiver 148. In some implementations, electrical cable head
146 may include a housing 168, an electrical conductor 170, and a
cable anchor 172. The housing 168 extends from a proximal end 174
to a distal end 176. The proximal end 174 may include an opening
178 through which the wireline cable 144 may extend. The opening
178 may lead to an anchor cavity 180 in communication with a
passage 182. The distal end 176 of the housing 168 may include a
threaded tip 184.
[0023] The electrical conductor 170 may be in electrical
communication with the center core 160 of the wireline cable 144.
In some implementations, the electrical conductor 170 may extend in
the passage 182 from the proximal end 174 to the distal end 176 and
may terminate at the threaded tip 184. In some implementations, the
electrical conductor 170 comprises a spring-loaded contact 186
projecting from the distal end 176 that contacts the signal
receiver 148.
[0024] The cable anchor 172 may be disposed within the anchor
cavity 180 and may be connected to the wireline cable 144. In some
implementations, the cable anchor 172 is attached to the armor
layer 164 of the wireline cable 144. In some implementations, the
center core 160 is electrically connected with the electrical
conductor 170 through the cable anchor 172. Some implementations
include an insulative cover about the electrical conductor 170. The
insulative cover may be for example a ceramic or polymeric material
that prevents electrical communication between the electrical
conductor 170 and the housing 168.
[0025] The signal receiver 148 is connected to the distal end 176
of the housing 168. The signal receiver 148 may be formed of a
heavy, conductive material. In some implementations, the signal
receiver 148 is formed of a solid stainless steel material. In
other implementations, the signal receiver 148 is formed of copper,
silver, or other highly conductive material and with features
aiding deployment and contact with formation or casing it is
deployed in. In the implementation shown, the signal receiver 148
is formed of a solid bulbous head 190 with sides 192 that taper
toward the housing 168, forming a frustum. A threaded bore or
threaded cavity 194 is disposed in the end of the frustum and
receives the threaded tip 184 of the housing 168. The signal
receiver 148 is formed to abut in direct contact with the walls or
sides of the auxiliary borehole 138 (FIG. 1) through which it is
introduced. Accordingly, the signal receiver 148 is in contact with
the natural geological formation of the auxiliary borehole 138. In
some embodiments, signal receiver 148 may contact the hole casing
in case of cased holes. As such, the signal receiver 148 also acts
as the signal receiver from the EM tool 130. Because the signal
receiver 148 is in direct contact with the subterranean formation,
the signal receiver 148 is configured and arranged to receive EM
signals from the EM tool 130 without interference or dampening from
unnatural components about the signal receiver 148. For example,
the signal receiver 148 is free of insulative or protective
materials that may interfere or dampen reception of signals. Also,
it is deployed deeper relative to a conventional EM antenna at the
surface which is prone to signal attenuation for long reach wells
and signal loss in case of salt domes in certain basins. Because of
this, the signal receiver 148 may be particularly sensitive to even
weak signals emitted from the EM tool 130 and propagated through
the subterranean formation. Furthermore, the electrically
conductive outer surface (the exterior surface) of the signal
receiver 148 is in direct electrical communication with the
electrical conductor 170 of the cable anchor 172, and with the
center core 160 of the wireline cable 144. This electrical
connection may be free of filtering or other signal distorting
components so that the signal communicated to the ground surface is
the complete and natural signal received at the signal receiver
148.
[0026] In this implementation, the shape of the signal receiver 148
may contribute to the receptivity of the EM signals. For example,
the bulbous head, having a diameter greater than the diameter of
the electrical cable head 146 insures that a significant portion of
the signal receiver 148 is in contact with the natural subterranean
formation. In the implementation shown, the signal receiver 148 has
the largest cross-sectional diameter of any of the wireline cable
144 or the electrical cable head 146. This may help increase the
likelihood that the signal receiver 148 will be in contact with the
subterranean formation whether disposed in a vertical auxiliary
borehole or in a curved or a horizontal auxiliary borehole.
[0027] FIG. 4 shows a perspective view of an example of a signal
receiver 148. The signal receiver 148 in this implementation
includes a rounded leading end 196 and a trailing end 198. The
tapering sides 192 taper toward the trailing end 198. In this
implementation, the signal receiver 148 has a substantially
teardrop-shape, with the rounded leading end 196 forming the large
diameter bulbous head. A notch 199 may be formed in a side to
enable the signal receiver 148 to be grasped by a tool for
threading onto the electrical cable head 146. In some
implementations, the signal receiver 148 has a diameter in the
range of about 2 to 12 inches, and has a length in a range of about
3 to 18 inches, although larger and smaller diameters and lengths
are contemplated. In some implementations, the signal receiver 148
has a diameter in the range of about 2 to 4 inches and has a length
in the range of about 4 to 8 inches. Furthermore, the rigidity of
the bulbous signal receiver reduces the likelihood of hang-up when
the signal receiver 148 is introduced and fed through the auxiliary
borehole 138. For example, a loose cable or other flexible
component at the distal end may interfere with advancement of the
signal receiving system 104.
[0028] In some implementations, an insulative covering may isolate
the signal receiver 148 from the housing 168 of the electrical
cable head 146. In such implementations, the signal receiver 148 is
still in electrical communication with the electrical conductor 170
projecting from the threaded tip 184 of the housing 168. In some
implementations, the electrical conductor 170 is the only component
in electrical communication with the signal receiver 148.
[0029] The signal processing system 142 may be disposed at the
surface adjacent the bore hole and may be configured to receive and
process signals detected or received at the signal receiver 148. In
some implementations, the processing system 142 is in direct
communication with the center core 160 of the wireline cable 144.
Accordingly, signals detected at the signal receiver 148 may be
communicated through the electrical cable head 146 and the wireline
cable 144 to the processing system 142. In some implementations,
the processing system 142 is a computer having software configured
to interpret EM signals received from the EM tool 130.
[0030] Because the signal receiver 148 is able to directly contact
the subterranean formations, and there is no isolation or
insulative elements between the signal receiver 148 and the center
core 160, EM signals may be more easily received and captured for
processing. The cable antenna 140 implementation shown in FIG. 3
may be a retrievable type and may be easily deployable by means of
coil tubing or wireline or the center conductor can be isolated or
connected to the polymeric material. In some implementations, this
receiver may be used for a multitude of wells being drilled across
the pad as well as nearby pads. In some implementations, the
wireline cable 144, the electrical cable head 146, and the signal
receiver 148 form a simple conductive connection having no control
feedback or logic system. It may receive and relay the signal to
the surface. In some implementations, the system does not require
electric/magnetic isolation between the center core and the
polymeric jacket. Furthermore, in some implementations, the system
does not require insulation between the signal receiver 148, the
electrical conductor 170, and the center core 160.
[0031] FIG. 5 is a flow diagram showing a process of using the
drilling telemetry system 100 according to an exemplary
implementation. At 502, a user may introduce the EM tool 130 to the
wellbore. The EM tool 130 may form a part of or be disposed
adjacent to a BHA during a drilling operation carried out by the
drilling rig system 102. In some implementations, the EM tool 130
may be spaced apart from the BHA, but may be downhole in the
subterranean formation.
[0032] At 504, a user may introduce the signal receiving system to
an auxiliary borehole. Because of the size and shape of the signal
receiver 148, the signal receiver may be in direct contact with the
natural subterranean formation. That is, because the signal
receiver 148 forms the distal most tip of the signal receiving
system, and because the signal receiver 148 may, in some
implementations, have a diameter larger than other components
around the signal receiver 148, the signal receiver 148 may be in
direct contact with the natural subterranean formation. Since the
signal receiver 148 is also un-insulated, EM signals propagated
through the subterranean formation may be detected or picked up
directly from the subterranean formation without interference or
dampening from insulative or isolating materials other than the
natural subterranean formation. The signal receiving system 104 may
be introduced to the auxiliary borehole with the electrical cable
head 146 and the signal receiver 148 suspended from the wireline
cable 144. The signal receiver and the electrical cable head 146
each include direct electrical contact with each other.
[0033] At 506, the EM tool 130 may transmit EM signals through the
subterranean formation. The signals may relate to detected
parameters of the wellbore and its surrounding environment, of the
drilling equipment, or of the subterranean formation. Accordingly,
the transmitted EM signals may include MWD or LWD information. The
EM signals may be transmitted while actual drilling is occurring,
or may be transmitted during down times of the drilling process,
such as when stands are being introduced to the drill string or
during other stoppages in actual drilling.
[0034] At 508, the signal receiver 148 may detect the EM signals
directly from the subterranean formation. Since the signal receiver
148 is particularly shaped to provide a large amount of surface
contact area, as well as have a wider diameter than other
components of the downhole signal receiving system, the signal
receiver 148 may receive signals left otherwise undetected by
conventional telemetry systems. In some implementations, the EM
signals are received only at the signal receiver. In such
implementations, the electrical cable head 146 and the wireline
cable 144 may include insulative or protective materials disposed
about their respective conductive portions that may inhibit
reception of EM signals transmitted or propagated through the
subterranean formation.
[0035] At 510, the detected signals may be communicated directly
from the signal receiver through the electrical cable head 146 and
the wireline cable 144 to the processing system 142. Since the
signal receiver is in direct electrical communication with the
electrical conductor of the electrical cable head 146, and since
the electrical conductor 170 is in direct electrical communication
with the center core 160 of the wireline cable 144, signals may be
communicated directly to the processing system 142, even when the
processing system 142 is disposed above ground. At 512, the
processing system 142 may interpret the signals at the surface.
[0036] In an exemplary aspect, the present disclosure is directed
to a drilling telemetry system that may include an EM tool sized
and configured to be disposed on a drill string and introduced into
a wellbore in a subterranean formation. The EM tool may comprise a
transmitter configured to transmit an electromagnetic signal
through the subterranean formation. The drilling telemetry sytem
may also include a cable antenna sized and configured to be
introduced into an adjacent auxiliary borehole in the subterranean
formation and arranged to receive the electromagnetic signal
transmitted from the EM tool. The cable antenna may comprise a
wireline cable having a center core, an insulated electrical cable
head in direct electrical communication with the center core, and
an uninsulated signal receiver in direct electrical communication
with electrical cable head. The uninsulated signal receiver may
have an outer surface formed of a conductive material and
configured to engage against a natural subterranean formation.
[0037] In some aspects, the uninsulated signal receiver has a
teardrop shape forming a bulbous head. In some aspects, the
uninsulated signal receiver comprises a threaded cavity formed
therein for receiving a portion of the electrical cable head. In
some aspects, the cable antenna comprises a polymeric jacket around
the center core, and a protective layer disposed around the
polymeric jacket. In some aspects, the armor layer is embedded
within and fixedly attaches the insulated electrical cable head to
the cable. In some aspects, the conductive material of the
uninsulated signal receiver comprises stainless steel. In some
aspects, the EM tool comprises a transmitter and a power source. In
some aspects, the uninsulated signal receiver has a diameter of
about 2 to about 12 inches, and a length of about 3 to about 18
inches.
[0038] In an exemplary implementation, a method of using a drilling
telemetry system may include introducing an EM tool to a wellbore;
introducing a signal receiving system to an adjacent auxiliary
borehole; transmitting an EM signal from the EM tool in the
wellbore; detecting the transmitted EM signal with the signal
receiver having a conductive exterior surface in direct contact
with walls of the auxiliary borehole, the conductive exterior
surface being in direct electrical communication with an electrical
cable head and a wireline cable; and communicating the detected EM
signal to a signal processing system in communication with the
wireline cable.
[0039] In some aspects, detecting the transmitted EM signal with
the signal receiver comprises detecting the transmitted EM signal
only at the signal receiver. In some aspects, the method may
include performing a drilling operation, and wherein transmitting
the EM signal from the EM tool occurs during the drilling
operation. In some aspects, the method may include insulating or
isolating a conductive center core in the wireline cable and a
conductor in the electrical cable head from contact with the walls
of the auxiliary borehole. In some aspects, communicating the
detected EM signal comprises communicating the detected EM signal
through a conductor in the electrical cable head and through a
conductive center core of the wireline cable. In some aspects, the
exterior surface of the signal receiver is in direct conductive
electrical communication with the conductor in the electrical cable
head. In some aspects, the method may include threading the signal
receiver on to a distal end of the electrical cable head to place a
spring-loaded contact in electrical communication with the signal
receiver. In some aspects, the uninsulated signal receiver has a
teardrop shape forming a bulbous head. In some aspects,
transmitting an EM signal comprises transmitting an EM signal
representative of one or more detected parameters of the wellbore,
an environment surrounding the wellbore, of the drilling equipment,
of the subterranean formation, or a combination thereof.
[0040] In an exemplary aspect, the present disclosure is directed
to a drilling telemetry system that includes an EM tool sized and
configured to be disposed on a drill string and introduced into a
wellbore in a subterranean formation. The EM tool may include a
transmitter configured to transmit an electromagnetic signal
through the subterranean formation. The drilling telemetry system
may also include a cable antenna sized and configured to be
introduced into an adjacent auxiliary borehole in the subterranean
formation and to receive the electromagnetic signal transmitted
from the EM tool. The cable antenna may include a wireline cable
having a center core, a polymeric insulative layer disposed about
the center core, and an outer protective layer disposed about the
polymeric insulative layer. The cable antenna also may include an
electrical cable head having a housing, an electrical conductor in
electrical communication with the center core of the wireline and
extending through the housing, and a cable anchor attached to the
outer protective layer and configured to secure the electrical
cable head to the wireline cable. The housing may have a distal end
having a spring-loaded contact. The cable antenna also may include
an uninsulated signal receiver disposed at a distal-most end of the
cable antenna and formed of a rigid, conductive material having a
diameter of about 2 to about 12 inches. The uninsulated signal
receiver may have a conductive outer surface exposed to engage
against a natural subterranean formation when the cable antenna is
disposed in borehole. The uninsulated signal receiver may be in
direct electrical communication with the spring-loaded contact to
provide uninterrupted electrical communication between the
conductive outer surface and the electrical conductor of the
electrical cable head.
[0041] In some aspects, the uninsulated signal receiver has a
teardrop shape forming a bulbous head. In some aspects, the
uninsulated signal receiver comprises a threaded cavity formed
therein for receiving a portion of the electrical cable head.
[0042] In several exemplary embodiments, the elements and teachings
of the various illustrative exemplary embodiments may be combined
in whole or in part in some or all of the illustrative exemplary
embodiments. In addition, one or more of the elements and teachings
of the various illustrative exemplary embodiments may be omitted,
at least in part, and/or combined, at least in part, with one or
more of the other elements and teachings of the various
illustrative embodiments.
[0043] Any spatial references such as, for example, "upper,"
"lower," "above," "below," "between," "bottom," "vertical,"
"horizontal," "angular," "upwards," "downwards," "side-to-side,"
"left-to-right," "right-to-left," "top-to-bottom," "bottom-to-top,"
"top," "bottom," "bottom-up," "top-down," etc., are for the purpose
of illustration only and do not limit the specific orientation or
location of the structure described above.
[0044] In several exemplary embodiments, while different steps,
processes, and procedures are described as appearing as distinct
acts, one or more of the steps, one or more of the processes,
and/or one or more of the procedures may also be performed in
different orders, simultaneously and/or sequentially. In several
exemplary embodiments, the steps, processes and/or procedures may
be merged into one or more steps, processes and/or procedures.
[0045] In several exemplary embodiments, one or more of the
operational steps in each embodiment may be omitted. Moreover, in
some instances, some features of the present disclosure may be
employed without a corresponding use of the other features.
Moreover, one or more of the above-described embodiments and/or
variations may be combined in whole or in part with any one or more
of the other above-described embodiments and/or variations.
[0046] Although several exemplary embodiments have been described
in detail above, the embodiments described are exemplary only and
are not limiting, and those skilled in the art will readily
appreciate that many other modifications, changes and/or
substitutions are possible in the exemplary embodiments without
materially departing from the novel teachings and advantages of the
present disclosure. Accordingly, all such modifications, changes
and/or substitutions are intended to be included within the scope
of this disclosure as defined in the following claims. In the
claims, any means-plus-function clauses are intended to cover the
structures described herein as performing the recited function and
not only structural equivalents, but also equivalent
structures.
[0047] The foregoing outlines features of several embodiments so
that a person of ordinary skill in the art may better understand
the aspects of the present disclosure. Such features may be
replaced by any one of numerous equivalent alternatives, only some
of which are disclosed herein. One of ordinary skill in the art
should appreciate that they may readily use the present disclosure
as a basis for designing or modifying other processes and
structures for carrying out the same purposes and/or achieving the
same advantages of the embodiments introduced herein. One of
ordinary skill in the art should also realize that such equivalent
constructions do not depart from the spirit and scope of the
present disclosure, and that they may make various changes,
substitutions and alterations herein without departing from the
spirit and scope of the present disclosure.
[0048] The Abstract at the end of this disclosure is provided to
comply with 37 C.F.R. .sctn. 1.72(b) to allow the reader to quickly
ascertain the nature of the technical disclosure. It is submitted
with the understanding that it will not be used to interpret or
limit the scope or meaning of the claims.
[0049] Moreover, it is the express intention of the applicant not
to invoke 35 U.S.C. .sctn. 112, paragraph 6 for any limitations of
any of the claims herein, except for those in which the claim
expressly uses the word "means" together with an associated
function.
* * * * *