The present invention relates to the field of communication in a downhole environment, particularly in a downhole network integrated into a drill string used in oil and gas exploration, or along the casings and other equipment used in oil and gas production. Gathering information of the actual operation of a drill string and the geological formations surrounding a well bore may assist drilling operations. Many systems have been disclosed which transmit information along a tool string, and these systems may be referred to in separate categories.
A first category includes references which employ direct electrical contacts between pipes. An example of such a system is U.S. Pat. No. 4,953,636 which is herein incorporated by reference for all that it discloses. The '636 patent discloses a pipe assembly for use in production or drilling systems. The pipe assembly comprises a plurality of pipe members connected together in end-to-end relationship and a plurality of tubular conductor members electrically connected together in end-to-end relationship. Other examples of such systems are disclosed in the following U.S. Pat. Nos. 6,296,066, 6,688,396; which are both incorporated by reference herein for all that they disclose.
A second category includes references which employ optical fibers and fiber optic couplers between pipes. An example of such a system is U.S. Pat. No. 6,734,805 which is herein incorporated by reference for all that it discloses. The '805 patent discloses a section of pipe for well operations which has a cylindrical fiber composite pipe body and a pair of metallic end fittings. Each pipe is also provided with an optical fiber for data transmission, and a fiber optic coupling is located at each end of the optical fiber for sending and receiving data transmissions via optical signals. Also disclosed is replacing the optical fiber with an electrical conductor, and the fiber optic coupling with electrical connectors and/or contacts.
A third category includes those references which employ inductive couplers between pipes. The term “inductive coupler” is herein intended to refer to a loop or loops of one or more wires and a path through the loop(s) through which inductive flux may flow. Generally an inductive coupler may transfer magnetic energy to another inductive coupler through mutual inductance between the two inductive couplers. The amount of magnetic energy transferred may be affected by the number of loops, the number of wires, magnetic permeability of material in the path through the loops, or proximity and orientation of one coupler to another. An example of a system which employs inductive couplers is U.S. Pat. No. 6,641,434 which is herein incorporated by reference for all that it discloses. The '434 patent discloses a wired pipe joint including a first annular coil fixedly mounted to a box-end, and a second annular coil fixedly mounted to a pin-end. The '434 patent also discloses a redundant system of two pairs (or more) of wires which could be run from end to end on each joint and two independent coil windings could be wound in each coupler, so that a single broken wire would not cause a system failure. Other examples of such systems are disclosed in the following U.S. Pat. No. 6,670,880 ('880 patent) and U.S. Pat. No. 6,866,306 which are herein incorporated by reference for all that they disclose.
A tubular component in a downhole tool string comprises a first end and a second end. The first end comprises first and second inductive couplers, and the second end comprises third and fourth inductive couplers. The component further comprises a first conductive medium and second conductive medium. The first conductive medium connects the first and third couplers, and the second conductive medium connects the second and fourth couplers.
The component may be selected from the group consisting of rigid pipes, coiled tubing, jars, mud hammers, motors, seismic tools, swivels, well casing, bottom-hole assemblies, shock absorbers, reamers, under-reamers, saver subs, steering elements, production pipes, and combinations thereof.
The terms “shoulder” is herein intended to refer to a portion of an end designed to carry weight and stress and which is designed to butt against a corresponding shoulder of another component. The ends of the component may have one or more shoulders. The first and second inductive couplers may be located in a secondary shoulder of the first end and the third and fourth inductive couplers may be located in a secondary shoulder of the second end. Alternatively, the first inductive coupler may be located in a primary shoulder of the first end, the second inductive coupler may be located in a secondary shoulder of the first end, the third inductive coupler may be located in a primary shoulder of the second end and the fourth inductive coupler may be located in a secondary shoulder of the second end.
The inductive couplers may comprise a coil disposed in a trough of magnetically conductive material. The magnetically conductive material may comprise a composition selected from the group consisting of ferrite, Ni, Fe, Cu, Mo, Mn, Co, Cr, V, C, Si, mu-metals, alloys, molypermalloys, metallic powder suspended in an electrically insulating material, and combinations thereof. The coils of the first and second inductive couplers may be disposed in a trident-shaped magnetically conducting material, and the coils of the third and fourth inductive couplers may be disposed in a trident-shaped magnetically conducting material.
The first and second conductive mediums may be selected from the group consisting of coaxial cables, shielded coaxial cables, twisted pair cables, triaxial cables, and biaxial cables. The component may further comprise electronic equipment disposed in the component. The electronic equipment may be selected from the group consisting of network nodes, repeaters, downhole tools, computers, modems, network interface modems, processors, memories, bottom-hole assemblies, seismic sources, seismic receivers, wireless transceivers, motors, turbines, amplifiers, MWD tools, LWD tools, sensors, pressure sensors, temperature sensors, pumps, perforators, other tools with an explosive charge, mud-pulse sirens, switches, routers, multiplexers, piezoelectric devices, magnetostrictive devices, optical transmitters, optical regenerators, optical receivers, optical converters and combinations thereof.
The first end of the component may be adapted to connect to a second end of a similar component, and the first and second inductive couplers of the component may be aligned with and proximate fifth and sixth inductive couplers of the similar component, respectively, when the components are connected.
The first inductive coupler, the third inductive coupler, and the first conductive medium may be electromagnetically independent from the second inductive coupler, the fourth inductive coupler, and the second conductive medium. The term “electromagnetically independent” is herein intended to refer to the ability to transmit electromagnetic signals which are distinguishable from other electromagnetic signals. A first path may be electromagnetically independent from a second path if signals transmitted along the first path are distinguishable from signals transmitted along the second path, although some interference or noise may exist between the first and second path.
The first end may further comprise a seventh inductive coupler, the second end may further comprise an eighth inductive coupler, and the component may further comprise a third conductive medium connecting the seventh and eighth inductive couplers. The seventh inductive coupler may be located in a tertiary shoulder of the first end and the eighth inductive coupler may be located in a tertiary shoulder of the second end. The inductive couplers may be capable of transmitting power.
Also disclosed is a component which comprises electronic equipment. The first end comprises a first plurality of inductive couplers and a conductive medium connecting each inductive coupler to the electronic equipment.
The component may comprise a ninth inductive coupler in the second end and a fourth conductive medium intermediate the inductive coupler and the electronic equipment. The first end may comprise more inductive couplers than the second end.
In one embodiment of the present invention, a downhole tool string comprises a plurality of components. Each component comprises a first end, a second end, and a data conductive medium intermediate and in communication with data couplers proximate the first and second ends. The tool string further comprises a power transmission path integrated into at least a portion of the tool string and electrically independent of the data conductive medium. The data couplers may be selected from the group consisting of inductive couplers, acoustic couplers, optic couplers, and direct contact couplers. The power transmission path may comprise a segmented medium joined by couplers selected from inductive couplers and direct contact couplers. Power may be generated downhole or on the surface and the power transmission path may connect downhole tools.
The terms “pin-end” and “box-end” are herein intended to refer to ends of a pipe which are designed to mate together. Generally speaking, a pin-end is intended to be inserted into a box-end.
a is a cross sectional view of an end of a component having three shoulders.
b is a cross sectional view of an end of a component having three shoulders.
a is a cross section view of a pair of couplers in a shoulder of a component.
b is a cross section view of a pair of couplers in a shoulder of a component.
Still referring to
The first and second inductive couplers 114, 115 may be located in a secondary shoulder 121 of the first end 111 and the third and fourth inductive couplers 116, 117 may be located in a secondary shoulder 123 of the second end 112. Alternatively, the first inductive coupler 114 may be located in a primary shoulder 120 of the first end 111, the second inductive coupler 115 may be located in a secondary shoulder 121 of the first end 111, the third inductive coupler 116 may be located in a primary shoulder 122 of the second end 112 and the fourth inductive coupler 117 may be located in a secondary shoulder 123 of the second end 112. It may be advantageous to place the couplers 114, 115, 116, 117 in the shoulders 120, 121, 122, 123 of the component 110 as the shoulders 120, 121, 122, 123 may be flat and the couplers 114, 115, 116, 117 may therefore be brought close to couplers in an adjacent component (not shown) to improve transmission between the couplers 114, 115, 116, 117 and the adjacent component. Furthermore, the component may comprise threads 124 in one or more ends, and couplers 114, 115, 116, 117 disposed among the threads 124 may weaken the threads 124.
The component 110 further comprises first and second conductive mediums 118, 119. The first conductive medium 118 connects the first and third inductive couplers 114, 116 and the second conductive medium 119 connects the second and fourth inductive couplers 115, 117. The first and second conductive mediums 118, 119 may be selected from the group consisting of coaxial cables, shielded coaxial cables, twisted pair cables, triaxial cables, and biaxial cables. The first inductive coupler 114, the third inductive coupler 116, and the first conductive medium 118 are electromagnetically independent from the second inductive coupler 115, the fourth inductive coupler 117, and the second conductive medium 119. This may be advantageous as independent signals may be transmitted along the conductive mediums 118, 119. A second conductive medium 119 may provide additional bandwidth over a system which only has one conductive medium. One or both of the conductive mediums 118, 119 may be used to transmit power and inductive couplers 114, 115, 116, and/or 117 may transmit power between adjacent components 110. This may be advantageous as it may provide power to downhole tools (not shown), as well as communication between components 110. For example, the first conductive medium 118 may be a data conductive medium, and the second conductive medium 119 may be a power conductive medium. The power may be generated downhole or on the surface and the second transmission 119 path may connect downhole tools (not shown). The second conductive medium 119 may be electrically independent of the first conductive medium 118.
Alternatively, a separate power transmission path (not shown) may be included in components 110, 210. The power transmission path may be a direct contact transmission path such as the system described in U.S. application Ser. No. 10/605,493 filed Oct. 2, 2003 in the name of Hall, et. al, which is herein incorporated by reference for all that it discloses.
Referring now to
First and second inductive couplers 114, 115 of the component may be aligned with and proximate fifth and sixth inductive couplers 216, 217 of the adjacent component 210, respectively, when the components 110, 210 are connected. The couplers 114, 115, 216, 217 may allow power and/or signals on the conductive mediums 218, 219 of the adjacent component 210 to be inductively coupled to conductive mediums 118, 119 in the body 113 of the component 110, thus allowing communication and power transfer across the joint.
An example of electronic equipment 313 disposed in the component 309 may be a network node which may communicate with other network nodes through the conductive mediums 118, 119, 312.
The electronic equipment 313 disposed in the component may comprise a sensor which communicates with other devices through the conductive mediums 118, 119, 312. The sensor may sense temperature, pressure, conductivity of drilling mud, or other measurable downhole characteristics.
The seventh inductive coupler 310 may be in a primary shoulder 120 of the first end 111, and the eighth inductive coupler 311 may be in a primary shoulder 122 of the second end 112. Alternatively, the seventh inductive coupler 310 may be in a tertiary shoulder 411 as illustrated in
b is a cross sectional view of an end of a component 410 having first and second couplers 114, 115 in secondary and tertiary shoulders 121, 411, respectively. Since the majority of stress in a downhole component may be in the primary shoulder 120, it may therefore be advantageous to have inductive couplers 114, 115 in other shoulders 121, 411.
An example of a component 510, 610 at the end of a tool string may be a component 510 which is a bottom-hole assembly 735 as illustrated in
A component 610 as seen in
In an alternate embodiment the component is a swivel 734 with electronic equipment 313 comprising a combination of optical receivers, optical transmitters, and optical converters. The swivel 734 may be connected to an optical fiber network on the earth's surface which may allow high data rates. The electronic equipment 313 may convert signals received from the optical fiber network into signals which may be transmitted along the conductive mediums 118, 119, 312 and vice versa. Thus, the electronic equipment may be an interface between two kinds of networks, and may function as a router. An optical fiber network may be advantageous as the bandwidth of the optical fiber network may be sufficient to transmit all the data from the swivel to the surface equipment 733.
An example of components having different numbers of inductive couplers 114, and conductive mediums may be seen in
Continuing with the embodiment, the component 810 of
Transmitting power to node 903 may be advantageous as node 903 may be near drill bit 918 and may comprise a bottom-hole assembly which may require additional power. Power transmitted to node 903 may supplement or replace power provided by a generator or battery in node 903. Furthermore, additional bandwidth and power transfer near the bottom of the downhole network 912 may be advantageous as the majority of tools currently in use are concentrated near the drill bit 918. These tools may therefore be powered by other nodes 902 in the network 912 and additional bandwidth may allow increased communication between tools. Furthermore, it may be advantageous to generate and transfer power near the bottom of the hole, as transmitting power over a short distance may be more efficient than transmitting power from a generator 739 (see
a and
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.
Number | Name | Date | Kind |
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7168510 | Boyle et al. | Jan 2007 | B2 |
Number | Date | Country | |
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20060260797 A1 | Nov 2006 | US |