U.S. patent application number 15/145476 was filed with the patent office on 2016-11-10 for piston converter for downhole drilling tool.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Jianjie Gao.
Application Number | 20160326805 15/145476 |
Document ID | / |
Family ID | 57221817 |
Filed Date | 2016-11-10 |
United States Patent
Application |
20160326805 |
Kind Code |
A1 |
Gao; Jianjie |
November 10, 2016 |
PISTON CONVERTER FOR DOWNHOLE DRILLING TOOL
Abstract
A steerable drilling tool in accordance to an embodiment
includes a steering actuator having an axially moveable piston
connected to a steering pad by a linkage to convert axial movement
of the piston into a radial movement of the steering pad.
Inventors: |
Gao; Jianjie; (Shanghai,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
57221817 |
Appl. No.: |
15/145476 |
Filed: |
May 3, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62158836 |
May 8, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 7/067 20130101;
E21B 17/1014 20130101 |
International
Class: |
E21B 7/06 20060101
E21B007/06; E21B 3/00 20060101 E21B003/00 |
Claims
1. A steerable drilling tool, comprising a steering actuator having
an axially moveable piston connected to a steering pad by a linkage
to convert axial movement of the piston into a radial movement of
the steering pad.
2. The tool of claim 1, wherein the steering pad comprises a rocker
assembly.
3. The tool of claim 1, comprising a seal circumferentially
encircling the axially moveable piston.
4. The tool of claim 1, wherein the steering pad comprises a rocker
assembly and further comprising a seal circumferentially encircling
the axially moveable piston.
5. The tool of claim 1, further comprising a pair of steering
components pivotally mounted to each other via a pivot joint and
extending axially along a tool axis; and the steering actuator
disposed with one of the pair of steering components such that
axial movement of the piston moves the steering pad radially
relative to the tool axis thereby pivoting the steering components
relative to one another.
6. The tool of claim 5, wherein the steering pad comprises a rocker
assembly.
7. The tool of claim 5, comprising a seal circumferentially
encircling the axially moveable piston.
8. The tool of claim 5, wherein the steering pad comprises a rocker
assembly and further comprising a seal circumferentially encircling
the axially moveable piston.
9. A method, comprising: deploying a bottom hole assembly (BHA) on
a drill string in a wellbore, the BHA comprising a drill bit and a
steering actuator comprising an axially moveable piston connected
to a steering pad by a linkage; axially moving the piston in
response to the application of a hydraulic pressure; radially
extending the steering pad in response to the axially moving the
piston; and steering the drill bit in response to radially
extending the steering pad.
10. The method of claim 9, wherein the steering pad comprises a
rocker assembly.
11. The method of claim 9, comprising a seal circumferentially
encircling the axially moveable piston.
12. The method of claim 9, wherein the steering pad comprises a
rocker assembly and further comprising a seal circumferentially
encircling the axially moveable piston.
13. The method of claim 9, wherein the radially extending the
steering pad comprises contacting the wellbore with the steering
pad.
14. The method of claim 9, wherein the radially extending the
steering pad comprises pivoting a first and a second steering
component relative to one another.
15. The method of claim 14, comprising a seal circumferentially
encircling the axially moveable piston.
16. A drilling system, comprising a bottom hole assembly (BHA)
deployed in a wellbore on a drill string, the BHA comprising a
drill bit and a steering actuator having an axially moveable piston
connected to a steering pad by a linkage to convert axial movement
of the piston into a radial movement of the steering pad.
17. The system of claim 16, comprising a seal circumferentially
encircling the axially moveable piston.
18. The system of claim 16, wherein the steering pad comprises a
rocker assembly and further comprising a seal circumferentially
encircling the axially moveable piston.
19. The system of claim 16, wherein the BHA comprises a pair of
steering components pivotally mounted to each other via a pivot
joint and extending axially along a tool axis, whereby the steering
components are pivoted relative to one another in response to
radially extending the steering pad.
20. The system of claim 19, comprising a seal circumferentially
encircling the axially moveable piston.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Patent Application No. 62/158,836,
filed May 8, 2015, which is incorporated herein by reference in its
entirety.
BACKGROUND
[0002] This section provides background information to facilitate a
better understanding of the various aspects of the disclosure. It
should be understood that the statements in this section of this
document are to be read in this light, and not as admissions of
prior art.
[0003] Oil and gas reservoirs may be accessed by drilling wellbores
to enable production of hydrocarbon fluid, e.g. oil and/or gas, to
a surface location. In many environments, directional drilling
techniques have been employed to gain better access to the desired
reservoirs by forming deviated wellbores as opposed to traditional
vertical wellbores. However, forming deviated wellbore sections can
be difficult and requires directional control over the orientation
of the drill bit used to drill the deviated wellbore.
[0004] Rotary steerable drilling systems have been used to drill
deviated wellbore sections while enabling control over the drilling
directions. Such drilling systems often are classified as
push-the-bit systems or point-the-bit systems and allow an operator
to change the orientation of the drill bit and thus the direction
of the wellbore.
SUMMARY
[0005] A steerable drilling tool in accordance to an embodiment
includes a steering actuator having an axially moveable piston
connected to a steering pad by a linkage to convert the axial
movement of the piston into a radial movement of the steering
pad.
[0006] A method includes deploying a bottom hole assembly (BHA) on
a drill string in a wellbore, the BHA including a drill bit and a
steering actuator having an axially moveable piston connected to a
steering pad by a linkage, axially moving the piston in response to
the application of a hydraulic pressure, radially extending the
steering pad in response to the axially moving the piston and
steering the drill bit in response to radially extending the
steering pad.
[0007] A drilling system includes a BHA deployed in a wellbore on a
drill string, the BHA including a drill bit and a steering actuator
having an axially moveable piston connected to a steering pad by a
linkage to convert the axial movement of the piston into a radial
movement of the steering pad.
[0008] This summary is provided to introduce a selection of
concepts that are further described below in the detailed
description. This summary is not intended to identify key or
essential features of the claimed subject matter, nor is it
intended to be used as an aid in limiting the scope of claimed
subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The disclosure is best understood from the following
detailed description when read with the accompanying figures. It is
emphasized that, in accordance with standard practice in the
industry, various features may not be drawn to scale. In fact, the
dimensions of various features may be arbitrarily increased or
reduced for clarity of discussion.
[0010] FIG. 1 is a schematic view of an example of a drill string
incorporating a steerable drilling system and piston converter
according to one or more aspects of the disclosure.
[0011] FIG. 2 illustrates an example of a steerable drilling tool
incorporating a steering actuator piston converter according to one
or more aspects of the disclosure.
[0012] FIG. 3 illustrates a point or hybrid type of steerable
drilling tool incorporating an axial piston and piston converter
according to one or more aspects of the disclosure.
[0013] FIG. 4 illustrates a push type steerable drilling tool
incorporating an axial piston and piston converter according to one
or more aspects of the disclosure.
[0014] FIG. 5 illustrates a prior art radial piston type of
steering actuator.
DETAILED DESCRIPTION
[0015] 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
disclosure. These are, of course, merely examples and are not
intended to be limiting. In addition, the 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.
[0016] As used herein, the terms connect, connection, connected, in
connection with, and connecting may be used to mean in direct
connection with or in connection with via one or more elements.
Similarly, the terms couple, coupling, coupled, coupled together,
and coupled with may be used to mean directly coupled together or
coupled together via one or more elements. Terms such as up, down,
top and bottom and other like terms indicating relative positions
to a given point or element are may be utilized to more clearly
describe some elements. Commonly, these terms relate to a reference
point such as the surface from which drilling operations are
initiated.
[0017] FIG. 1 illustrates a drilling system 20 in which piston
converters 10 for steerable systems can be incorporated. System 20
includes a bottom hole assembly (BHA) 22 which is part of a drill
string 24 used to form a directionally drilled wellbore 26. The
illustrated bottom hole assembly 22 of drilling system 20 includes
a steerable drilling assembly 28, e.g. a rotary steerable system,
which controls the drilling orientation of a drill bit 30. The
steerable drilling assembly 28 in FIG. 1 is illustrated as a hybrid
type system including steerable system components 32, 34 which
pivot with respect to each other to enable the desired directional
drilling of wellbore 26. Steering actuators 36 may be mounted
between components 32 and 34 to control the pivoting of component
34 with respect to component 32 by providing the desired lateral
forces for steering the steerable drilling assembly 28 when forming
the desired, deviated wellbore 26. The steerable system components
32, 34 may be coupled together by a pivot joint 38, such as a
universal joint. The illustrated steerable drilling system is a
non-limiting example of a steerable drilling system in which
embodiments of this disclosure can be incorporated.
[0018] The depicted steering actuators 36 incorporate a piston
converter, generally denoted by the numeral 10, operationally
connecting an axially aligned piston 12 to a radially moveable pad
14. The axial movement of piston 12 is transferred to the radial
movement of pad 14. A control system generally identified with the
numeral 40 selectively directs drilling fluid to the steering
actuators 36 to extend the pads 14 radially or laterally relative
to the bottom hole assembly (e.g., too, drill string) and into
contact with the outer steerable component 34 (e.g., sleeve) or
into contact with the wellbore wall to steer the drill bit 30. The
control system 40 may include for example control electronics 42
and one or more valves 44 (e.g., spider valve, bistable valve,
etc.). The steering actuator can be provided in various forms.
Non-limiting examples of steerable systems in which the piston
convert can be utilized are disclosed in U.S. Pat. Nos. 8,590,636,
8,701,795, 8,708,064, 8,763,725 and 9,057,223, the teachings of
which are incorporated herein by reference.
[0019] Depending on the environment and the operational parameters
of the drilling job, drilling system 20 may comprise a variety of
other features. For example, drill string 24 may include drill
collars 46 which, in turn, may be designed to incorporate desired
drilling modules, such as logging-while-drilling and/or
measurement-while-drilling modules 48. In some applications,
stabilizers may be used along the drill string to stabilize the
drill string with respect to the surrounding wellbore wall. Various
surface systems also may form a part of the drilling system 20. In
the example illustrated, a drilling rig 50 is positioned above the
wellbore 26 and a drilling mud system 52 is used in cooperation
with the drilling rig. For example, the drilling mud system 52 may
be positioned to deliver drilling fluid 54 from a drilling fluid
tank 56. The drilling fluid 54 is pumped (pump 53) through
appropriate tubing 58 and delivered down through drilling rig 50,
into drill string 24, and down through drill bit 30. In many
applications, the return flow of drilling fluid flows back up to
the surface through an annulus 60 between the drill string 24 and
the surrounding wellbore wall (see arrows 62 showing flow down
through drill string 24 and up through annulus 60). The drilling
system 20 also may comprise a surface control system 64 which may
be used to communicate with steerable drilling assembly 28. In some
embodiments, the surface control system 64 communicates with a
downhole steering control system within steerable drilling assembly
28.
[0020] FIG. 2 schematically illustrates a non-liming example of a
steerable drilling assembly 28 incorporating a steering actuator 36
and piston converter 10 in accordance to an embodiment. With
additional reference to FIG. 1, the illustrated steerable drilling
assembly 28 is in the form of a rotary steerable system which
utilizes the steering actuators 36 to control the relative angular
orientation between steering components 32 and 34. The steering
components 32 and 34 are pivotally coupled to each other via pivot
joint 38 which, in this particular example, is in the form of a
universal joint. Downhole drilling tools generally utilized the
pumping pressure (pump 53), of the drilling fluid 54 to control the
steering actuator 36. The drilling fluid is directed for example by
the downhole steering control system 40, through a control valve 44
to the piston 14 of the steering actuator 36 to drive the piston 12
axially relative to the axis 66 which in turn radially extends the
pad 14 outward relative to the longitudinal axis 66 of the tool
(e.g., BHA). In accordance to embodiments, the piston converter 10
is a mechanical link. In the example of FIG. 2, the pad 14 extends
radially outward to apply a steering force and pivot the steering
components 32, 34 relative to one another. In some steerable tools
the pads are extended radially from the drilling tool to contact
and apply the steering force to the wall of borehole.
[0021] FIGS. 3 and 4 are schematic illustrations of steerable
drilling tools 28 incorporating steering actuators 36 utilizing a
piston converter 10 in accordance to one or more aspects of the
disclosure. The piston 12 is moveably disposed in a longitudinally
extending cylinder 68, i.e., along the longitudinal axis 66 of the
tool, as opposed to being oriented in the radial direction. Piston
converter 10 is a mechanical linkage that transfers the axial
movement of the piston 14 into a radial movement of the pad 14.
[0022] The piston cylinder 68 is oriented in the axial direction
with the piston 12 movement and the piston push in the axial
direction in response to the application of hydraulic fluid 54,
e.g. drilling mud. The piston cylinder 68 is longer and the
movement of piston 12 is longer than that permitted in a radial
piston arrangement, see e.g., U.S. Pat. No. 8,590,636. The longer
axial movement allows for more lifting movement of the rocker
assembly 70 (see, FIG. 4) and the pad 14. During operation the pad
(e.g., the top surface) or other components wear and/or become
washed out requiring that the pad assembly move further radially
than prior to the wear. The axial piston facilitates the additional
radial movement without compromising the piston seal 72, e.g. the
piston seal pushed out of the pressure chamber. The circular shaped
seal 72 (e.g., O-ring) circumferentially encircling the axially
moving piston 12 is a reliable seal. FIG. 3 illustrates the piston
converter arranged in a point-type or hybrid-type steerable tool
and FIG. 4 illustrates the piston converter arranged steering
actuator in a push-the-bit steerable drilling tool.
[0023] FIG. 5 illustrates an example of a prior art steering
actuator able drilling tool and prior art radial piston assembly. A
further description of a prior art radial piston assembly is
disclosed in U.S. Pat. No. 8,590,636, the teachings of which are
incorporated herein by reference. Hydraulic pressure, e.g., the
drilling mud 54, acts on the actuator piston 12 causing it to move
radially relative to the longitudinal axis 66 of the steerable
drilling tool as it pivots about the hinge pin 74. Because of the
space restriction in the radial direction, the opening angle 76 of
the hinged piston may be limited to around six degrees. Space is
restricted, or limited, in the radial direction according to the
drilling tool size. During drilling operations the piston rocker
top surface 70 and other components may wear, permitting the piston
to open greater than the original limit. When this happens, the
dynamic piston seal 78 may pop out of the metal pocket and the
sealing mechanism may be damaged. This could result in washout of
the piston and reduction in the steering performance of the
drilling tool.
[0024] The foregoing outlines features of several embodiments so
that those skilled in the art may better understand the aspects of
the disclosure. Those skilled in the art should appreciate that
they may readily use the 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. Additionally, it should be understood that
references to "one embodiment" or "an embodiment" of the present
disclosure are not intended to be interpreted as excluding the
existence of additional embodiments that also incorporate the
recited features. For example, features shown in individual
embodiments referred to above may be used together in combinations
other than those which have been shown and described specifically.
Accordingly, any such modification is intended to be included
within the scope of this disclosure. In the claims,
means-plus-function clauses are intended to cover the structures
described herein as performing the recited function and not just
structural equivalents, but also equivalent structures. Thus,
although a nail and a screw may not be structural equivalents in
that a nail employs a cylindrical surface to secure wooden parts
together, whereas a screw employs a helical surface, in the
environment of fastening wooden parts, a nail and a screw may be
equivalent structures. It is the express intention of the applicant
not to invoke means-plus-function for any limitations of any of the
claims herein, except for those in which the claim expressly uses
the words `means for` together with an associated function.
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