Patent Application
20160326804
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.
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.
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.
A steerable drilling tool includes a steering pad radially moveable relative to a longitudinal tool axis and a pressure amplifier operationally connected to the steering pad to increase a hydraulic fluid pump pressure applied to the steering pad. A method in accordance with aspects of a method includes applying a first hydraulic pressure to a pressure amplifier operationally connected to a steering pad located in a bottom hole assembly (BHA) having a drill bit and disposed in a wellbore, driving a piston of the pressure amplifier axially relative to a longitudinal axis of the BHA and moving the steering pad with a steering force radially away from the longitudinal axis of the BHA in response to driving the piston axially.
A drilling system includes a drill string having a BHA carrying a drill bit, a steering pad carried by the BHA and radially moveable relative to a longitudinal axis of the BHA and a pressure amplifier connected between the steering pad and a hydraulic fluid at a first pressure, the pressure amplifier comprising a piston axially moveable in response to application of the first hydraulic pressure to move the steering pad radially at a steering force.
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.
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 are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.
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.
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.
Referring generally to
A control system generally identified with the numeral 40 selectively directs drilling fluid to the steering actuators 36 to extend the actuators radially or laterally relative to the 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.). A pressure amplifier 10 is operationally, hydraulically and or physically, connected to each of the steering actuators 36 to multiple the pump pressure that is applied to the steering actuator. The steering actuator can be provided in various forms including steering pistons or balls having an outer profile or pad to contact the steering sleeve or wellbore wall, the steering actuator can include a hinged member that pivots relative to the tool to extend radially or laterally outward. Non-limiting examples of steerable systems in which the pressure amplifier 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.
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.
The steering actuators 36 (e.g., pistons, balls) are moved from retracted positions toward extended positions by supplying the drilling fluid, under pressure, to the cylinders 70 associated therewith, return movement occurring as the drilling fluid is able to escape from the cylinders through an exhaust 72. The supply of fluid to the cylinders 70 from a fluid conduit 74 via pressure amplifiers 10 is controlled by control valves 44. The operation of control valves 44 are controlled for example by controller 42 using information from, for example, inclination and azimuth sensors 76. The control valves, controller and sensors may be electrically powered from a power source 78 such as a load cell or battery.
To achieve steering of the drilling direction, the controller 42 controls the valves 44 so as to determine which of the steering actuators 36 is in the extended position. By extending the steering actuator and pad 37 into engagement with the wellbore wall a laterally acting reaction force is applied to the collar 46 and hence to the drill bit 30. By moving the steering actuator as the collar rotates the reaction force can be applied in a substantially constant direction resulting in the formation of curve or dogleg in the borehole.
In the example of
where PInlet is the inlet pressure of fluid 54, e.g., pump pressure, X is the number of stages, A83 is the area of the second input surfaces and A88 is the area of the output surface area.
The pressure improvement over the pump pressure (inlet pressure) is:
With reference to
The amplifier shaft 84 and cylinder 85 are oriented axially, i.e. along longitudinal axis 66 of the tool, to accommodate the space limitations in a downhole tool. In the example of
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.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/158,829, filed May 8, 2015, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62158829 | May 2015 | US |
