U.S. patent application number 10/194929 was filed with the patent office on 2003-03-27 for apparatus and method for simultaneous drilling and casing wellbores.
This patent application is currently assigned to Baker Hughes Incorporated. Invention is credited to Hahn, Detlef, Makohl, Friedhelm.
Application Number | 20030056991 10/194929 |
Document ID | / |
Family ID | 22618582 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030056991 |
Kind Code |
A1 |
Hahn, Detlef ; et
al. |
March 27, 2003 |
Apparatus and method for simultaneous drilling and casing
wellbores
Abstract
The present invention provides apparatus and method for drilling
a wellbore wherein a pilot wellbore section is drilled with a bit
which section is enlarged by a trailing underreamer to the desired
size. One or more steering sections between the underreamer and the
drill bit are utilized for maintaining and changing the drilling
direction. Each steering section includes a plurality of
independently adjustable force application devices on a
non-rotating sleeve. If an expandable liner is used, then an
expansion device disposed above the underreamer expands the liner
during retrieval of the drilling assembly to the surface.
Inventors: |
Hahn, Detlef; (Hannover,
DE) ; Makohl, Friedhelm; (Hermannsburg, DE) |
Correspondence
Address: |
PAUL S MADAN
MADAN, MOSSMAN & SRIRAM, PC
2603 AUGUSTA, SUITE 700
HOUSTON
TX
77057-1130
US
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
22618582 |
Appl. No.: |
10/194929 |
Filed: |
July 12, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10194929 |
Jul 12, 2002 |
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09733220 |
Dec 8, 2000 |
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6419033 |
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60170108 |
Dec 10, 1999 |
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Current U.S.
Class: |
175/61 ;
175/73 |
Current CPC
Class: |
E21B 10/26 20130101;
E21B 7/208 20130101; E21B 7/068 20130101; E21B 7/20 20130101; E21B
17/1014 20130101; E21B 43/103 20130101; E21B 7/062 20130101 |
Class at
Publication: |
175/61 ;
175/73 |
International
Class: |
E21B 007/04 |
Claims
What is claimed is:
1. An apparatus for drilling a wellbore, comprising: (a) a liner
for casing the wellbore; (b) a drill bit at a first end of a
drilling assembly for drilling a pilot wellbore; (c) at least one
set of a plurality of force application devices on a non-rotating
sleeve of the drilling assembly, each said force application device
independently operable to exert force on the pilot wellbore for
controlling direction of drilling of the wellbore; and (d) an
underreamer disposed uphole of the at least one set of the force
application devices adapted to enlarge the pilot wellbore to
produce said wellbore when rotated.
2. The apparatus of claim 1, wherein said drilling assembly is
conveyed on a drilling tubular selected from a group consisting of
(i) a drill string, and, (ii) a coiled tubing.
3. The apparatus of claim 1, wherein the at least one set of a
plurality of force application devices further comprises two
spaced-apart sets of a plurality of force application devices.
4. The apparatus of claim 1, wherein the liner is expandable, the
apparatus further comprising a liner expansion device that expands
the liner when said drilling assembly is retrieved from said
wellbore.
5. The apparatus of claim 1 wherein the drilling assembly further
comprises a drilling motor for rotating the drill bit.
6. The apparatus of claim 1 further comprising a control unit that
controls the force application devices to exert desired force on
the pilot wellbore.
7. The apparatus of claim 6 further comprising a program associated
with said control unit that includes a prescribed wellbore path and
wherein the control unit controls the force application devices to
maintain drilling along the prescribed wellbore path.
8. The apparatus of claim 6 further comprising a sensor providing a
measure of a parameter of interest and wherein the control unit
adjusts the force applied by the force.
9. A method of drilling a wellbore comprising: (a) conveying a
drilling assembly on a drilling tubular into the borehole; (b)
using a drill bit conveyed on a first end of the drilling assembly
for drilling a pilot wellbore; (c) using a plurality of force
application devices on a non-rotating sleeve of the drilling
assembly for independently exerting a force on the pilot wellbore
and controlling the direction thereof; (d) using an underreamer
disposed near a second end of the drilling assembly and enlarging
the pilot wellbore to produce said wellbore; and (e) using a liner
coupled to the underreamer for lining said borehole.
10. The method of claim 9, wherein the drilling tubular is selected
from a group consisting of (i) a drill string, and, (ii) a coiled
tubing.
11. The method of claim 10, wherein the liner is expandable, the
method further comprising retrieving the drilling assembly from the
wellbore, the method further comprising using a liner expansion
device on the drilling assembly for expanding the liner during said
retrieval.
12. The method of claim 10 further comprising using a drilling
motor in the drilling assembly for rotating the drill bit.
Description
REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Application Serial Number 60/170,108 filed on Dec. 10, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to oilfield drilling
operations and more particularly to simultaneous drilling and
casing of wellbores with a drill string utilizing a liner or casing
and a steerable drilling assembly.
[0004] 2. Background of the Art
[0005] In conventional manner, oil wells (wellbores) are drilled
with a drill string having a drilling assembly with a drill it at
its bottom, and a tubular member (either a jointed pipe or coiled
tubing) attached to the drilling assembly that extends to the
surface. Once a section of the well has been drilled, the drill
string is retrieved to the surface and a casing, which extends to
the surface, is set in the well to protect the open hole. A liner
is hung below the upper casing using a liner hanger connection
device, which usually includes two threaded connections at its
bottom. The liner is connected to the outer thread. The inner
threaded connection is used to connect a string inside that liner,
which string extends below the liner hanger. The next section of
the wellbore is drilled below the first liner and this procedure is
repeated until the telescopically declining diameter wellbore is
drilled to the desired depth. Such drilling methods require
tripping the entire drill string out of the wellbore for lining
each telescopic section of the wellbore.
[0006] Wellbores are sometimes drilled wherein the liner itself is
employed to carry the drilling assembly. The drilling assembly used
for such operations includes a drill bit at the bottom to drill a
pilot (small diameter) hole followed by an underreamer which
enlarges the pilot hole to a size greater than the outer dimensions
of the liner. The drilling assembly is retrievably attached to the
liner bottom and can be retrieved without retrieving the liner.
[0007] To drill curved holes, the underreamer drilling assemblies
typically use a bent housing (also referenced to as a "bent sub")
whose attitude is fixed either at the surface or downhole, which
attitude defines the drilling direction. Such drill strings are
sometimes unable to provide precision directional drilling.
[0008] The present invention provides apparatus and method for
drilling wellbores with liners which allow relatively precise
directional control. This invention further provides apparatus and
method wherein an expandable liner may be used during the drilling
process, which liner can ne expanded while the drilling assembly is
retrieved to the surface, thereby avoiding a secondary operation
required to expand the expandable liner.
SUMMARY OF THE INVENTION
[0009] The present invention provides apparatus and method for
drilling a wellbore with a drilling assembly wherein a pilot
wellbore section is drilled with a bit which section is enlarged by
a trailing underreamer to the desired size. The drilling assembly
includes one or more steering sections between the underreamer and
the drill bit are utilized for maintaining and changing the
drilling direction. Each steering section includes a plurality of
independently adjustable force application devices on a
non-rotating sleeve. The drilling assembly is retrievably attached
at its upper end to a liner that will be set in the wellbore once
at least a section of the wellbore has been drilled. The liner may
be any suitable tubing including a expandable liner. If an
expandable liner is used, then an expansion device disposed above
the underreamer is utilized to expand the liner during retrieval of
the drilling assembly to the surface.
[0010] The independently adjustable force application devices
provide for a relatively precise control of the direction of
drilling. A control unit on the surface and/or in the drilling
assembly controls the force applied by each of the force
application devices in accordance with programmed instructions
and/or commands provided from surface. One or more sensors in the
drilling assembly and at the surface provide information about
various parameters of interest, including the tool face of the
drilling assembly, force applied by each application device, and
position of the drilling assembly. The control unit includes an
electronic processor (computer, microprocessors and the like) and
controls the operation of the force application device, at least in
part, in response to or as a function of one or more 20 parameters,
of interest, thereby controlling and/or maintaining the drilling
direction along a desired path.
[0011] Examples of the more important features of the invention
thus 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 of the invention that will be
described hereinafter and which will form the subject of the claims
appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For detailed understanding of the present invention,
references should be made to the following detailed description of
the preferred embodiment, taken in conjunction with the
accompanying drawings, in which like elements have been given like
numerals and wherein:
[0013] FIG. 1 is a schematic diagram of a horizontal wellbore being
drilled with a drilling assembly of the present invention conveyed
by a liner.
[0014] FIG. 2 shows an example of the application of independent
forces on the borehole wall by the drilling assembly of FIG. 1 to
maintain and control the drilling direction.
[0015] FIG. 3 is an alternative embodiment of the drilling assembly
according to the present invention for use with a drilling
liner.
[0016] FIG. 4 shows an example of the application of independent
forces on the borehole wall by the drilling assembly of FIG. 3 to
maintain and control the drilling direction.
[0017] FIG. 5 shows a drilling assembly that can expand an
expandable liner as the drilling assembly is tripped out of the
wellbore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIG. 1 is a schematic diagram showing a drilling system 100
with a liner drill string for drilling wellbores according to one
embodiment of the present invention. FIG. 1 shows a wellbore 110
that includes an upper section 111 with a casing 112 installed
therein, and a lower section 114 (which is smaller in diameter than
the upper section 111) being drilled with a liner drill string 118
that includes a drilling assembly 130. The drilling assembly 130 is
attached to the bottom end 120b of the liner 120, which extends to
a rig 180 at the surface 167. A rotary table 169 or a top drive
(not shown) may be utilized to rotate the liner and thus the
drilling assembly 130.
[0019] Alternatively, the drilling assembly 130 may be conveyed
through the liner 120 via a coiled tubing 171 from a reel (source)
172 at the rig 180. The rig 180 also includes conventional devices,
such as mechanisms to add additional sections to the liner 120 as
the wellbore is drilled, a control unit 190, including computers
for receiving and processing downhole data and for controlling
operation of the various devices in the drilling assembly 130. A
drilling fluid from a source thereof 179 is pumped under pressure
through the liner 120 or through a tubing run inside the liner 120.
Such apparatus and methods are known in the art and are not
described in greater detail herein.
[0020] The drilling assembly 130 includes a drill bit 131 at its
bottom end for drilling a pilot hole 141 (also referred to herein
the first or leading section of the wellbore) and an underreamer
132 uphole or above the drill bit 131. The underreamer 132 has
cutting members 132a which extend radially farther than the drill
bit outside dimensions and thus can drill or expand the pilot hole
to a larger diameter. The underreamer 132 has a plurality of
cutting members 132a which can be extended outward so that the
upper section 142 is larger than the drill string and drilling
assembly dimensions. The dimension of the upper section 142 is the
same as the dimension of the wellbore 110. This provides a wellbore
that has a desired annulus 149 between the wellbore inside and the
drill string 118.
[0021] A steering section or unit 145 between the drill bit 131 and
the underreamer 132 provides downhole steering control for drilling
wellbore 110 relatively precisely along a predefined or desired
well path. The steering section 145 includes a non-rotating sleeve
144 that carries a plurality of independently controllable steering
devices 146, each such device having an independently adjustable
force application member 146a that can exert desired forces on the
wellbore wall. Each steering device 146 may be integrated into the
non-rotating sleeve 144. When the liner 120 is rotated from the
surface, it rotates the drill bit, but the non-rotating sleeve 144
remains substantially stationary relative to the drill bit
rotational speed. The sleeve 144 may rotate at a few rpm while the
drill bit rotates usually between 60-200 rpm. The operation of the
steering devices is described in more detail in reference to FIGS.
2 and 4. A control and measuring unit 147 controls the operation of
each steering device 146. The control unit 147 preferably includes
a hydraulic pump that supplies fluid under pressure to the force
application members. A separate pump may be utilized for each force
application device. An electrical motor or another suitable device
may also be utilized to extend the force application members to
exert force on the wellbore wall.
[0022] The drilling assembly 130 further includes a drilling motor
(usually a mud motor) 149 which is utilized to rotate the drill bit
131 and may also be utilized to operate the underreamer 132. The
control unit 147 may also be used to control the radial extension
of the underreamer cutting members 132a or a separate control unit
may be provided. Alternatively, the underreamer 132 may have fixed
outside dimensions. The drilling assembly 130 is detachably
attached to the liner 120 at an end 120a via a connection device
152. A variety of connection devices are known in the art. Any
suitable mechanism may be utilized to attach the drilling assembly
130 to the liner 120. In such a configuration, the drilling
assembly 130 is pulled out or retrieved or tripped out of the
wellbore 110 by a tubing or wireline conveyed from the surface.
[0023] A coiled tubing 171, however, may be used to convey the
drilling assembly through the liner 120. In such a configuration,
the drilling fluid is pumped through the coiled tubing 171. The mud
with the cuttings (rocks disintegrated by the drill bit 131 and the
underreamer) may flow through the annulus 149. If a coiled tubing
is used inside the linear, the mud with the cuttings may be made to
flow through the spacing between the coiled tubing and the liner
inside (not shown).
[0024] The steering unit 145 includes one or more sensors 153 for
providing signals indicative of the borehole inclination. Three
axis accelerometers are commonly used as inclination sensors. A
position sensor is used to determine the position of the drilling
assembly or drill bit relative to a known position. The drilling
assembly direction is determined via one or more suitable sensors.
The drilling assembly 130 also may include any of the
measurement-while-drilling and formation evaluation sensors. Such
sensors include, resistivity sensors, gamma-ray detection sensors,
magnetometers, and a variety of other sensors, such as nuclear,
acoustic and nuclear magnetic resonance sensors. Such sensors are
commercially available and are used in drilling assemblies and are
thus not described herein.
[0025] The drilling of the wellbore 110 will now be described while
referring to FIGS. 1 and 2. The drill string 118 is conveyed in the
wellbore. The drill bit is rotated by the mud motor (when mud motor
is used) and/or by rotating the liner 120 from the surface. The
drill bit 131 drills the pilot hole of a first (smaller) diameter.
The underreamer cutting members 132a are expanded to a desired
size, which enlarges the pilot hole to the required wellbore size.
To alter the drilling direction, the control unit 147 activates one
or more of the steering devices 146. As shown in FIG. 2, each
steering device includes an expandable force application member
(also referred herein as a "rib") such as the rib 146a. Each
expanded rib 146a exerts a predetermined force on the wellbore wall
110a. The combination of the amounts of the forces exerted by the
ribs determines the drill bit direction. In FIG. 2, the drilling
direction is shown to have been altered from the prior direction
denoted by line or axis 201 by a X.sub.1 degrees to the current
direction denoted by the axis 203.
[0026] In one method of the present invention, the command signals
may be transmitted or telemetered downhole by the surface control
unit 190, which, as stated above, preferably is a computer-based
system. The downhole steering control unit 147, in response to the
command signals, activates the specified ribs to apply the
predetermined force on the wellbore wall 110a to achieve or
maintain the desired drilling direction. In an alternative method,
the desired well path may be programmed into a memory unit
associated with the steering control unit 147. The control unit 147
then periodically determines the actual drilling direction from the
sensors 153, compares this direction with the desired well path and
causes the various steering devices to adjust their respective
forces on the wellbore so that the combined effect causes the drill
bit to drill the wellbore 110 along the prescribed well path. The
operating parameters relating to the drilling direction
(inclination, azimuth etc.) may also be transmitted to the surface
where the surface control unit 190 may be utilized to send control
signals to the downhole controller 147 to override the actions of
the downhole control unit 147. The downhole control unit 147 may
also be reprogrammed by telemetered signals from the surface
control unit 190. One or more sensors, such as a pressure sensor or
displacement sensor associated with each rib 146a provides signals
indicative of the force applied by its associated rib on the
wellbore wall. Programs are stored in the downhole control unit 147
to calculate the force vector on the drill bit 131.
[0027] Thus, in one embodiment of the present invention, the
wellbore is drilled by a drilling assembly conveyed in the wellbore
by a liner (or casing) that is not retrieved, and wherein the
drilling assembly includes a downhole controllable steering unit
between a drill bit and an underreamer, which steering unit
includes one or more independently-controllable steering device on
a non-rotating sleeve for maintaining and altering the drilling
direction. The steering unit may be self-adjusting or controlled
from the surface. The method preferably is closed loop, in that the
drilling is performed along a prescribed well path and that the
drilling direction is altered when the actual drilling direction
deviates from the prescribed well path. The drilling assembly is
retrievably attached or conveyed into the wellbore without
requiring tripping out of the liner.
[0028] FIG. 3 shows an alternative embodiment of the drilling
assembly 300 which is substantially similar to the drilling
assembly 130 but includes two spaced apart steering units 310 and
320. Each such steering unit includes a plurality of steering
devices on corresponding non-rotating sleeves 311 and 321. The
steering units 310 and 320 operate in manner described above with
reference to FIGS. 1-3. The use of two spaced-apart independently
adjustable steering units can improve the directional drilling
behaviors of the drilling system 100 of FIG. 2. The upper steering
unit 320 is above the main steering unit 310 and is preferably
mounted on a non-rotating sleeve to allow full secondary three
dimensional ("3D") control or may be mounted on a rotating member
or sleeve to allow for two dimensional ("2D") control of the upper
steering unit 310. The underreamer 315 is located above the upper
steering unit 320. FIG. 4 shows an example wherein the lower
steering unit 310 and upper steering unit 320 exert force on
opposite sides of the borehole wall to achieve a greater turning
radius. In the example of FIG. 4, the lower steering unit 310
applies force on the bottom side 301a of the wellbore 301 (as shown
by the arrow 311a) while the upper steering unit 320 applies force
on the upper side 301b of the wellbore, as shown by the arrow 311b.
The multiple steering unit configuration allows greater flexibility
to control and maintain the drilling direction.
[0029] FIG. 5 shows an embodiment 410 of the present invention in
which an expandable liner 420 is used. A liner expansion device 425
is disposed uphole of the underreamer 415, which device is adapted
to expand the expandable liner 420 as the drilling assembly 400 is
retrieved from the wellbore. The liner expansion device 425
includes an outer member 426 that is suitable for expanding the
liner 420. After the well is drilled to a target depth, the
drilling assembly 410 is pulled to the surface, the liner expansion
device runs through the expandable liner 420, thereby expanding it
to the larger diameter defined by the outer dimensions of the
expansion device 425. Any suitable expansion device may be utilized
for the purpose of this invention.
[0030] Thus, in the present invention, a pilot wellbore section is
drilled with a drill bit, which is enlarged by a trailing
underreamer to the desired size. One or more steering sections
between the underreamer and the drill bit that include
independently adjustable force application devices on one or more
non-rotating sleeves are utilized to maintain and change the
drilling direction. If an expandable liner is used, then an
expansion device disposed above the underreamer expands the liner
during retrieval of the drilling assembly to the surface.
[0031] The foregoing description is directed to particular
embodiments of the present invention for the purpose of
illustration and explanation. It will be apparent, however, to one
skilled in the art that many modifications and changes to the
embodiment set forth above are possible without departing from the
scope and the spirit of the invention. It is intended that the
following claims be interpreted to embrace all such modifications
and changes.
* * * * *