WO2016133748A1

WO2016133748A1 - Bottom hole assembly connections

Info

Publication number: WO2016133748A1
Application number: PCT/US2016/017209
Authority: WO
Inventors: Edward George PARKIN; Michael Pearce
Original assignee: Schlumberger Technology Corporation; Schlumberger Canada Limited; Services Petroliers Schlumberger; Schlumberger Technology B.V.
Priority date: 2015-02-16
Filing date: 2016-02-09
Publication date: 2016-08-25

Abstract

A non-threaded connection of adjacent members in a tubular string includes a pin section disposed inside of a female end and a holding member having a first surface in contact with an interior surface of female end and a second surface in contact with an outer surface of the pin section. The holding member may be wedge shaped and apply a clamping force to axially and rotationally lock the adjacent members together.

Description

BOTTOM HOLE ASSEMBLY CONNECTIONS

RELATION APPLICATIONS

This patent application claims priority to and the benefit of U.S. Provisional Patent Application Number 62/116,880, filed on February 16, 2015, which is incorporated herein by reference.

BACKGROUND

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. Forming deviated wellbore sections can be difficult and requires directional control over the orientation of the drill bit used to drill the deviated wellbore.

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. Drill pipe and tools (e.g., drill bit, motor, measurement and logging while drilling modules, jars, reamers etc.) in the bottom hole assembly are generally interconnected by field separable connections, such as a standard API (American Petroleum Institute) connection.

SUMMARY In accordance to an aspect of this disclosure a non-threaded connection of adjacent members in a tubular string includes a pin section disposed inside of a female end and a holding member having a first surface in contact with an interior surface of female end and a second surface in contact with an outer surface of the pin section. The non-threaded connection may include one or more communication lines extending axially across the connection. A method includes disposing a pin section of a second member of a wellbore tubular string into a female end of a first member of the wellbore tubular string, placing a holding member radially through a window of the female end with a first surface of the holding member contacting an interior surface of the female end and a second surface of the holding member contacting an outer surface of the pin section, the holding member being wedge shaped and with a length and an inclined angle between the first and second surfaces extending from a nose to a tail end and with the length positioned laterally across the pin section, and securing the holding member in place relative to the connection end and the pin section second members thereby axially and rotationally locking the first and second members together. In accordance to an aspect of the disclosure a bottom hole assembly of a drilling system has a female end of a first member axially and rotational locked with a pin section of a second adjacent member by a non-threaded connection.

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

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.

Figure 1 is a schematic view of a drill string and drilling system incorporating a steerable drill bit in accordance to one or more aspects of the disclosure.

Figure 2 illustrates a non-threaded connection allowing cross -communication of hydraulic, optical and electronic lines in accordance to one or more aspects of the disclosure.

Figures 3 and 4 are cut-away views of a non-threaded connection allowing cross- communication of hydraulic, optical and electronic lines in accordance to one or more aspects of the disclosure.

Figures 5 and 6 illustrate a non-threaded connection of a cutter matrix with a tubular member in accordance to one or more aspects of the disclosure.

Figure 7 is a cut-away view of a non-threaded connection of a cutter matrix with a tubular member in accordance to one or more aspects of the disclosure.

Figure 8 is a graphical illustration of an example of clamping force utilizing a non-threaded connection in accordance to one or more aspects of the disclosure.

DETAILED DESCRIPTION

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.

Embodiments of non-threaded connections, generally denoted by the numeral 10, between members are disclosed with reference to Figures 1-8. The non-threaded connections 10 rotationally and axially lock or secure the adjacent tubular members together. The non-threaded connections can be utilized without limitation in tubular strings such as for example wellbore tubular strings. In accordance to one or more embodiments the non-threaded connection is utilized to connect a cutting matrix, e.g. a drill bit, reamer, to a tubular such as a drill collar or a drill shaft. The non-threaded connection can be utilized to connect adjacent tubular elements, such as and without limitation pipe joints, drill collars, drill bits and drive shafts. In accordance to some embodiments, the non-threaded connection provides for linking communication across the non- threaded connection; for example, physically interconnecting, linking or extending communication lines for example in the form of hydraulic conduits, electrical conductors, and optic fibers. Communication across conventional rotary connections is difficult to achieve, in particular physically extending communication lines through the side wall or otherwise inside of the interconnected tubular members. Referring generally to Figure 1, a drilling system 20 is illustrated incorporating non- threaded connections 10. The illustrated drilling system 20 includes a bottom hole assembly (BHA) 22 which is part of a wellbore tubular string 24, e.g. drill string, used to form a desired, directionally drilled wellbore 26. The illustrated drilling system 20 comprises a steerable drilling system 28, e.g. a rotary steerable system (RSS), generally including a bias unit 30 to steer the drill bit 32 (i.e., cutter matrix) and an electronic steering control unit or system (e.g., processor, memory, etc.) generally denoted by the numeral 62. Bias unit 30 includes control valves 34 (e.g., electrically operated digital valve) for directing drilling fluid to steering actuators 36, e.g., pistons and pads, for example through a hydraulic communication line 56 (i.e., conduit). Extending the steering actuators 36 provides the desired lateral forces for steering the drill bit 32 and forming the desired deviated wellbore 26. The drill bit 32 may be physically connected to a collar 38 via a non-threaded connection 10. Electrical power is provided to the control system 62 and the bias unit 30 from an electrical source 64, such as batteries and/or a mud driven turbine. The control system 62 may be in communication and designed to interact with sensors 60 to sense various parameters including without limitation the toolface direction and thus the direction the wellbore is being propagated. The steering control system may be constructed as a closed loop control for closing the control loop between the directional measurements received from sensors and steering actuator output via the steering actuators. The sensor or sensors 60 may be located in various locations in the drill string or bottom hole assembly. In accordance to some embodiments, the sensors 60 may be incorporated into the drill bit.

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, in particularly the BHA 22, may include drill collars 38, which in turn, may be designed to incorporate desired drilling modules such as logging-while drilling (LWD) modules and/or measurement-while- drilling (MWD) modules 40. The adjacent pipe joints and/or collars may be interconnected via a non-threaded connection 10. The electrical systems of the modules 40 may be electrically connected, for example via electrical conductor or lines 58, to the control valves 34 (e.g., digital valves) to supply the timing control signals to the control valves 34 and actuators 36. In some embodiments, the drilling system includes a drilling mechanics module 41 (DMM). The electrical power source 64 and the control system 62 are in operational and electrical connection with the bias unit 30 in the depicted system. Communication connections (e.g., electric, hydraulic, and optical) across various components, e.g., pipe joints, collars, etc., can be provided by the non- threaded connection 10 disclosed herein.

In accordance to embodiments, the steering system may include a drilling mud motor 37.

For example, in Figure 1, the modules 40, 41 are separated from the bias unit 30 and drill bit 32 by the drilling mud motor. The drilling motor 37 may be physically connected to the drill bit 32 by a tubular drive shaft via a non-threaded connection 10. To communicate past the mud motor, electromagnetic wave transmission system may be utilized. Power and communications may be passed through or across the mud motor using wires. Due to the rotation, orbital and axial motion of the mud motor rotor with the drill collar slip rings may be utilized to allow the wires to rotate. Electrical power and/or communication may also be communicated across the mud motor utilizing wire and coil connections.

Various surface systems also may form a part of the drilling system 20. In the example illustrated, a drilling rig 42 is positioned above the wellbore 26 and a drilling mud system 44 is used in cooperation with the drilling rig. For example, the drilling mud system 44 may be positioned to deliver drilling fluid 46 from a drilling fluid tank 48. The drilling fluid 46 is pumped through appropriate tubing 50 and delivered down through drilling rig 42 and into drill string 24. In many applications, the return flow of drilling fluid flows back up to the surface through an annulus 52 between the drill string 24 and the surrounding wellbore wall (see arrows showing flow down through drill string 24 and up through annulus 52). The drilling system 20 also may comprise a surface control system 54 which may be used to communicate with steerable system 28. The surface control system 54 may communicate with steerable system 28 in various manners including through the non-threaded connections disclosed herein.

Figures 2-7 illustrate examples of non-threaded connections 10 between adjacent tubular members 66, 68. The non-threaded connection 10 includes a holding member 70, referred to herein as a wedge, in contact with the adjacent tubular members 66, 68 to apply a clamping force as further described below with reference to Figure 8 to secure the members together. The adjacent tubular members may take various forms, such as and without limitation pipe joints, collars, reamers, drive shafts, reamers and drill bits. In Figures 2-4 the adjacent tubular members are identified as pipe joints or collars, for example drill collars. In Figures 5-7 the adjacent tubular members 66, 68 are identified as a cutting matrix (e.g., drill bit, reamer) and a tubular such as a pipe joint, collar, drive shaft. Utilizing the non-threaded connection 10 to connect the drill bit reduces the length of the assembly required for threaded connections. This reduction in length can provide significant advantages to the steering capability in particular with regard to dog-leg capability. In some embodiments, the non-threaded connection physically extends one or more communication lines (e.g., electric, optical, hydraulic) across the non-threaded connection and internal to the outside surface of the adjacent tubulars. Figures 2-4 illustrate the non-threaded connection 10 physically connecting the adjacent tubular members 66, 68 and providing a physical signal communication connection across the tubular connection. A communication line generally denoted by the numeral 72 is illustrated extending across the adjacent tubular members 66, 68. Communication line 72 may be for example a hydraulic line (conduit), electrical conductor, or optical fiber cable. Communication line 72 is illustrated extending through a passage 74 formed axially through the sidewall 76 of the tubular members 66, 68. A feed connection 78 interconnects the passage 74 of the adjacent tubular members 66, 68. The communication line 72 extends through the feed connection 78. Feed connection 78 may include one or more external seal elements 80 (e.g., elastomeric seals) to seal passage 74 of both of the tubular members 66, 68. Feed connection 78 may take various configurations, for example as a conduit through which the communication line 74 can be passed or as communication line link into which the communication line can be connected to interconnect the two sections of the communication line. Although not illustrated the non-threaded connections 10 illustrated in Figures 5-7 can include a communication line connection, for example to connect devices (e.g., sensors, valves, actuators) in the cutting matrix with a control unit, power source or other uphole system or device.

The adjacent tubular members 66, 68 have respective connection ends 82, 84 that are adapted to interconnect the adjacent tubulars without threading or welding. In accordance to one or more embodiments, the adjacent tubulars are adapted to form a sealed connection (e.g., seal element(s) 80 and/or mating shoulders) suitable for the operational environment. One of the tubular members 66, 68 has a male connection end 82 having a pin end or section 86 having an outside diameter sized to be disposed into a bore 88 of a female connection end 84 of the other one of the adjacent tubulars 66, 68. For the purpose of ease in description, tubular 66 is illustrated as having the pin section 86 and tubular member 68 is illustrated as having the associated female connection end 84 in Figures 2-7. As will be understood by those skilled in the art with benefit of this disclosure, the male connection end 82 and the female connection end 84 may be arranged on the opposite tubular members from the arrangements illustrated in Figures 2-7.

The pin section 86 includes a trap 90 formed on its outer surface and sized to dispose a portion of the holding member 70. For example, the trap 90 may be formed with a floor surface 92 extending laterally relative to the longitudinal axis of the adjacent tubular members. The floor surface 92 may be recessed and positioned between opposing sidewalls. A window 94 is formed through the sidewall 76 of the female connection end 84 of the tubular 68 providing an opening into the bore 88. The trap 90 and window 94 are positioned such that trap 90 is aligned with the window 94 when the pin section 86 is inserted into the bore 88. The wedge 70 is inserted into the window 94 so that the holding member 70 is in contact with the adjacent tubulars 66, 68; for example, an outer surface of the wedge is in contact with an interior surface 98 of the female connection end 84 and the inner surface of the wedge opposite the outer surface is in contact with the floor 92 of the pin section, see e.g., Figures 2, 3, 6, 7 and 8. The wedge 70 is secured in a clamping position in contact with both tubular members for example with one or more fasteners 96. The fasteners 96 are illustrated as bolts extending through the window 94, wedge 70, and secured to the female connection end on the opposite side from the window. For example, with reference to Figure 4 the fastener 96 is threaded into the inside wall 95 of tubular member 68 opposite from the window to apply a force to the wedge 70 and create the clamping force as further described below with reference to Figure 8. In the Figure 7 example the fastener 96 is threaded into the inside wall 95 of the tubular member 68 at a threaded insert 97.

Figure 8 is a free body illustration of the clamping force applied to the adjacent tubulars utilizing a non-threaded connection. The connection clamping force "W" is now described with to Figures 2-7. The holding member or wedge 70 has a key length 4 extending from a nose 71 at an incline angle (a) to tail end 73 having a key height 6. In the clamping position one of the opposing first and second wedge surfaces 75, 77 (i.e., the surfaces inclined relative to one another) is contacting the pin section 86, i.e. along outer surface 92 of the trap 90, and the other wedge surface of the opposing wedge surfaces 75, 77 is contacting the bore 88 of the female connection end 84 along an interior surface 98, see e.g. Figure 3. The opposing first and second surfaces of the holding member may also be referred to as the outer or top surface for example oriented toward the outer female connection end and the inner or bottom surface oriented toward the pin section. The connection clamping force "W" applied between the adjacent tubulars 66, 68 by a wedge 70 may be determined by the equation:

P

w= —

tan(a+ Φ)

Wherein:

W = Connection Clamping Force; n*d²

As = Effective sectional area of fastener 96 (As = ); oy = Yield strength of fasteners 96; P= Force provided by the fasteners 96 (i.e., tensile load): P = [(Safety Factor (0.7) * oy As) * (No. of Fasteners)] ; μ = Coefficient of friction: μ^η Φ;

Φ = Angle of Friction (static): Φ = tan^'1 μ; and a = the angle of incline of the wedge.

For example, a M16 thread size class 12.9 steel fastener 96 is utilized having a yield strength (oy) of 112 kilogram-force (kgf) per square millimeter (mm²⁾ and an effective sectional area (As) of about 154 mm². The force (P) provided by a single fastener 96 at for example 70 percent (0.70) of the yield strength of the fastener is about 12,073.6 kgf.

Using a coefficient of friction (μ) between steel and aluminum-bronze of 0.45 the angle of friction (Φ) is 24.227, the tangent of the wedge angle (a) plus the angle of friction (Φ) is 0.5256. A wedge 70 connected by a single fastener 96 (e.g., Figure 6) according to this example would provide a connection clamping force (W) to the adjacent tubular members of about 22,971 kgf per wedge. Utilizing two fasteners 96 per wedge (e.g., Figures 2-3) according to this example would provide a clamping force (W) of about 45,942 kgf per wedge.

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. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the disclosure. The scope of the invention should be determined only by the language of the claims that follow. The term "comprising" within the claims is intended to mean "including at least" such that the recited listing of elements in a claim are an open group. The terms "a," "an" and other singular terms are intended to include the plural forms thereof unless specifically excluded.

Claims

WHAT IS CLAIMED IS:

1. A non-threaded connection, comprising:

a first member having a female end;

a second member having a pin section disposed inside of the female end; and

a holding member having a first surface in contact with an interior surface of female end and a second surface in contact with an outer surface of the pin section.

2. The non-threaded connection of claim 1, comprising a communication line extending axially across the first and second members.

3. The non-threaded connection of claim 1, comprising a communication line extending axially through a passage formed in sidewalls of the respective first and second members.

4. The non-threaded connection of claim 1, wherein the holding member is disposed in a window formed radially through as sidewall of the first member.

5. The non-threaded connection of claim 1, comprising a fastener securing the holding

member in contact with the first and the second members.

6. The non-threaded connection of claim 1, wherein the holding member is a wedge having a length and an inclined angle between the first and second surfaces extending from a nose to a tail end, wherein the length is positioned laterally across the pin section.

7. The non-threaded connection of claim 6, comprising a fastener securing the holding

member in contact with the first and the second members, wherein the holding member applies a clamping force between the first and second members.

8. The non-threaded connection of claim 1, comprising two or more holding members

wherein each of the holding members is a wedge having a length and an inclined angle between the first and second surfaces extending from a nose to a tail end, wherein the length is positioned laterally across the pin section; and

each holding member secured in place by a fastener.

The non-threaded connection of claim 1, further comprising a communication line extending axially across the first and second members and passing through sidewalls of the respective first and second members;

a fastener securing the holding member in contact with the first and the second members; and

the holding member disposed in a window formed radially through the sidewall of the first member.

The non-threaded connection of claim 9, wherein the holding member is a wedge having a length and an inclined angle between the first and second surfaces extending from a nose to a tail end, wherein the length is positioned laterally across the pin section.

The non-threaded connection of claim 10, wherein the fastener is connected to the holding member and to the first member at a position opposite from the window.

The non-threaded connection of claim 9, comprising two or more holding members wherein each of the holding members is a wedge having a length and an inclined angle between the first and second surfaces extending from a nose to a tail end.

A method, comprising:

disposing a pin section of a second member of a wellbore tubular string into a female end of a first member of the wellbore tubular string;

placing a holding member radially through a window of the female end with a first

surface of the holding member contacting an interior surface of the female end and a second surface of the holding member contacting an outer surface of the pin section, wherein the holding member is a wedge having a length and an inclined angle between the first and second surfaces extending from a nose to a tail end, wherein the length is positioned laterally across the pin section; and

securing the holding member in place relative to the female end and the pin section

thereby axially and rotationally locking the first and second members together.

The method of claim 13, wherein the securing comprises connecting the holding member with a fastener to the first member at a position opposite the window.

15. The method of claim 13, wherein the securing comprises applying a force to the holding member in a direction lateral to the pin section thereby creating a clamping force between the first and the second members.

16. The method of claim 13, further comprising extending a communication line through sidewalls of the respective first and second tubular members.

17. A wellbore drilling system, comprising:

a bottom hole assembly having a female end of a first member axially and rotational locked with a pin section of an adjacent second member by a non-threaded connection, the non-threaded connection comprising:

a holding member having a first surface in contact with an interior surface of the female end and a second surface in contact with an outer surface of the pin section, wherein the holding member has a length and an inclined angle between the first and second surfaces extending from a nose to a tail end; and

a fastener securing the holding member in contact with the female end and the pin

section.

18. The system of claim 17, wherein one of the first member and the second member

comprises a cutting matrix.

19. The system of claim 17, wherein one of the first member and the second member is a drill bit.

20. The system of claim 17, further comprising a communication line extending through the first and second members and across the non-threaded connection.