Patent Application
20100224416
In a variety of wellbore drilling operations, wired drill pipe is used to carry signals along the wellbore. Each wired drill pipe comprises conductive end connections that enable the connection of a series of wired drill pipes to form a wired drill string. The wired drill pipe is deployed by a drilling system having a rig, such as a land-based rig or an off-shore rig. The drill string is suspended in the wellbore by the rig; and a drill bit at the lower end of the drill string is used for drilling the wellbore.
Electrical connections between wired drill pipes are formed via a variety of mechanisms and in various configurations. For example, electrical connections between drill pipes have been created with the aid of several types of springs. However, such spring connections can have problems with long-term reliability, mating alignment, and other issues.
In other applications, inductive couplers have been used to enable transfer of signals along wired drill strings, and those connections are useful in many environments. However, inductors effectively amplify the connection resistance by the square of the number of turns in the inductor. For example, with 100 turn inductors, 10 milliohms of connection resistance effectively becomes 10 ohms of connection resistance when reflected through the inductors. As a result, very low connection resistance is desired, but low connection resistance is nearly impossible when forming wired drill pipe connections in the field. Debris between connectors, glazing, corrosion, and other effects can also increase the connection resistance.
Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present invention generally relates to a system and method for facilitating communication of signals in a wellbore, such as along a wired drill string. The system and method may utilize wired drill pipes that have connection ends designed to facilitate the transfer of signals from each wired drill pipe to the next sequential wired drill pipe along the wired drill string. The connection ends may incorporate a plurality of unique or independent conductive connectors that engage each other upon connection of one of the wired drill pipes to the next sequential wired drill pipe. In many types of applications and environments, the plurality of independent conductive connectors can be used to avoid, for example, the amplifying effects of inductors.
Each wired drill pipe connection end may use independent conductive connectors to establish at least two conductive connections having low resistance and high reliability. The conductive connections may improve the transfer of signals, such as electrical signals, along the entire wired drill string which, in turn, facilitates operation of downhole equipment and receipt of data from the downhole equipment. In an embodiment, the conductive connectors are formed as at least two flat contact surfaces that may be isolated from each other. The flat contact surfaces of one wired drill pipe are forced into contact with the flat contact faces of the next adjacent drill pipe when the wired drill pipes are engaged by, for example, threaded engagement.
The wired drill pipe connection ends can vary in size, design and material selection, one type of connection end, for example, is a threaded connection end. The design of the threaded connection ends provides surfaces, e.g. faces, which can be used to position a plurality of conductive connectors separated by insulation material. Various mechanisms also can be used for wiping the conductive connector faces during engagement of the threaded connection end with a corresponding threaded connection end. Furthermore, various connection end configurations can be selected and used to establish multiple, e.g. two or more, signal transfer connections between wired drill pipes.
Referring generally to
In the embodiment illustrated, each wired drill pipe comprises a first connection end 34 and a second connection end 36. The first connection end 34 of one wired drill pipe 28 is connected to the second or corresponding connection end 36 of the next adjacent wired drill pipe 28. The wired drill pipes 28 are sequentially joined as the downhole equipment 24 is deployed further into wellbore 22 during, for example, a drilling operation. Additionally, each wired drill pipe 28 comprises a communication line, such as a conductor 38, which extends from the first connection end 34 to its second connection end 36. By way of example, the conductor 38 may comprise an electrical conductor in the form of an insulated wire or other type of conductor disposed within the wall forming the wired drill pipe 28.
If the wired drill pipes 28 are connected to each other, the conductors 38 are automatically and conductively coupled to form a communication line along the wired drill string 26 for transferring signals between, for example, downhole equipment 24 and a surface location. As illustrated in
The wired drill pipes 28 are connected to each other by various connection mechanisms. However, one example of a suitable connection mechanism is illustrated schematically in
Each connection end 34, 36 comprises a plurality of conductive connectors that are automatically engaged when connection end 34 is joined with connection end 36 of the next adjacent wired drill pipe. For example, first connection end 34 may comprise a plurality of first conductive connectors 44 that are operatively engaged with the conductor 38, which extends along the length of the wired drill pipe. Similarly, the second connection end 36 may comprise a plurality of second or corresponding conductive connectors 46 that also are operatively engaged with the conductor 38. When adjacent wired drill pipes 28 are joined together, the first conductive connectors 44 of one wired drill pipe 28 are moved into conductive engagement with the second conductive connectors 46 of the next adjacent wired drill pipe 28 to enable, for example, transfer of electric signals.
Conductive connectors 44, 46 are arranged to create a plurality of independent conductive paths between adjacent wired drill pipes 28 upon joining of the wired drill pipes 28. Furthermore, the conductive connectors 44, 46 are protected from the flows of fluid that may be directed along the interior, longitudinal passages 48 of the wired drill pipes 28. By way of example, the first conductive connectors 44 may be formed as generally flat surfaces along a face 50 of connection end 34, and second conductive connectors 46 may be formed as corresponding, generally flat surfaces along a face 52 of connection end 36. If the first connection end 34 is in the form of threaded pin end 40, the face 50 may be located along its distal end in an orientation generally perpendicular to a longitudinal axis 54 of the wired drill pipe 28. The corresponding face 52, containing the second conductive connectors 46, may be located at the base of the recessed, threaded box end 42 in an orientation generally perpendicular to the longitudinal axis 54. Accordingly, when threaded pin end 40 is threaded into threaded box end 42, the first conductive connectors 44 are forced or otherwise positioned against corresponding second conductive connectors 46 to form conductive connections along plural, independent conductive paths.
Conductive connectors 44 and 46 may be designed in a variety of configurations and orientations depending on the type of connection formed between adjacent wired drill pipes. However, one example of a conductive connector arrangement is illustrated in
Referring again to
Referring again to
In another embodiment illustrated in
The corresponding face, e.g. the face 52, is designed with relatively short conductive contact sections 64 separated by longer sections 66 of insulating material 58, as illustrated in
In some applications, additional independent conductive contacts may also be established. In the embodiment illustrated in
Referring generally to
In other designs, the conductive contacts 44, 46 need not be created as generally flat surfaces along an end face. As illustrated in
Generally, the well system 20 may be constructed with a variety of well equipment components, including various configurations of the wired drill string. Additionally, the wired drill string may be formed of wired drill pipes having many sizes and structures. For example, the wired drill pipes may comprise an assortment of communication lines for transferring many types of signals. Furthermore, the connection ends may employ various numbers, arrangements and configurations of the conductive contacts to establish plural conductive connections and independent electrical current flow paths. The plurality of independent, conductive connections greatly facilitates the dependable transfer of desired signals while avoiding, for example, the multiplication effect of an inductor on the contact resistance. The connection mechanisms described herein also improve the reliability of the connection relative to conventional connections, such as spring connections.
Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims.
