Patent Application
20070023185
The present invention relates to the field of downhole drilling. More specifically, it relates to downhole tools in a tool string with protected integrated circuits.
Due to high costs associated with drilling for hydrocarbons and extracting them from underground formations, efficiency in drilling operations is desirable to keep overall expenses down. Electronic equipment may be useful in drilling operations to accomplish many tasks, such as providing identification information about specific downhole components to surface equipment, performing downhole measurements, collecting downhole data, actuating tools, and other tasks.
Notwithstanding its utility in the drilling process, downhole has proven to be a rather hostile environment for electronic equipment. Temperatures downhole may reach excesses of 200° C. Shock and vibration along a tool string may knock circuitry out of place or damage it. A drilling mud with a high pH is often circulated through a tool string and returned to the surface. The drilling mud and other downhole fluids may also have a detrimental effect on electronic equipment downhole exposed to it.
In the art, a first group of attempts to protect downhole electronics comprises an apparatus with electronic circuitry in a sonde that is lowered into a borehole by a cable periodically throughout the drilling process. The sonde provides protection from downhole conditions to the electronic circuitry placed inside. Examples of this type of protection (among others) may be found in U.S. Pat. No. 3,973,131 to Malone, et al. and U.S. Pat. No. 2,991,364 to Goodman, which are herein incorporated by reference.
A second group comprises adapting downhole tools to accommodate and protect the electronic circuitry. In this manner the electronic circuitry may remain downhole during drilling operations. For example, U.S. Pat. No. 6,759,968 discloses the placement of an RFID device in an O-ring that fills a gap in a joint of two ends of pipe or well-casing. U.S. Pat. No. 4,884,071 to Howard discloses a downhole tool with Hall Effect coupling circuitry located between an outer sleeve and an inner sleeve that form a sealed cavity.
A downhole tool comprises a tubular body having threaded ends, an exterior wall, and a bore. At least one of the ends typically comprises a mating surface formed intermediate the exterior wall and the bore. The mating surface may be a primary mating surface or a secondary mating surface, and is adapted to receive a radio frequency identification (RFID) or other integrated circuit. The mating surface may have a groove, or other recess formed upon it, and the integrated circuit may be disposed within the recess. The downhole tool may comprise several integrated circuits disposed within the mating surface. In such a case, the mating surface may comprise a plurality of recesses with integrated circuits disposed within them, or a plurality of integrated circuits may be disposed within a single recess. The end may also comprise a plurality of shoulders having grooves and a plurality of integrated circuits disposed within the recesses.
The integrated circuit may be encapsulated in a protective material that substantially conforms to the dimensions of the recess and secures the integrated circuit in addition to protecting it from potentially damaging downhole conditions. The integrated circuit may be a passive circuit or an active circuit. For active circuits, a power source may also be disposed within the recess and deliver electrical power to the integrated circuit. In embodiments where the integrated circuit comprises RFID circuitry, the circuitry may be configured to store and transmit an identification signal.
The downhole tool may also have an inductive coupler disposed within the recess. The inductive coupler may be in electromagnetic communication with both a downhole network and the integrated circuit, allowing the integrated circuit to communicate with devices in the downhole network. An RFID integrated circuit in electromagnetic communication with the inductive coupler may therefore be in communication with surface equipment through the downhole network. The RFID circuit may comprise a direct electrical connection to the inductive coupler, especially when the inductive coupler acts as an external antenna for the RFID circuit. The inductive coupler may comprise an electrically conducting coil lying in a magnetically conductive, electrically insulating trough.
A tool identification system comprises surface equipment with RFID interrogating circuitry and a downhole tool with an integrated RFID circuit. The RFID interrogating circuitry and the integrated RFID circuit in the downhole tool string component are in electromagnetic communication with each other through a downhole network.
A method for identifying a downhole tool in a downhole tool string comprises the steps of transmitting an interrogating signal from surface equipment to the downhole tool and receiving the interrogating signal in RFID or other identification circuitry disposed within a mating surface of the downhole tool. The interrogating signal may be transmitted to the downhole tool through a downhole network integrated into the tool string.
The method further comprises the steps of transmitting an identification signal modulated with identification data from the identification circuitry to the surface equipment through the downhole network and demodulating the identification data from the identification signal to identify the downhole tool. The identification data may be a serial number comparable to information in a database, and the interrogation signal may be transmitted at about 13.56 MHz.
It should be understood that for the purposes of this specification the term “integrated circuit” refers to a plurality of electronic components and their connections produced in or on a small piece of material. Examples of integrated circuits include (but are not limited to) circuits produced on semiconductor substrates, printed circuit boards, circuits produced on paper or paper-like substrates, and the like.
It should also be understood that for the purposes of this specification the term “protected” refers to a state of being substantially secure from and able to function in spite of potential adverse operating conditions.
Referring to
The box end 103 of the downhole tool 100 comprises a primary mating surface 101, which in the shown embodiment is a primary shoulder. The primary mating surface 101 is intermediate the exterior wall 109 and the bore 110. The primary mating surface 101 is adapted to couple to a primary mating surface 208 in a second downhole tool 209 (see
The integrated circuit 106 may be a radio frequency identification (RFID) circuit. Preferably, the integrated circuit 106 is a passive device powered by a received electromagnetic signal. In other words, an interrogation signal received by the integrated circuit 106 may provide the energy necessary to power the circuit 106. This particular characteristic may be desirable as it may eliminate the need of providing and periodically replacing a power supply for each integrated circuit.
An integrated circuit 106 comprising RFID circuitry may be desirable for various applications—for instance, the circuitry may store identification information such as a serial number that it may provide to an RFID query device (e.g. a hand-held wand, a fixed RFID interrogator, etc.) upon receiving an interrogating signal.
The integrated circuit 106 may be encapsulated in a protective material 108. The protective material 108 may conform to the dimensions of the recess 105. The protective material 108 may be a permanent potting material such as a hard epoxy material. In other embodiments, the protective material 108 may be a less permanent potting material such as rubber, foam, and the like. The protective material 108 may guard the integrated circuit 106 from downhole fluids such as drilling mud and oil. When the threaded box end 103 of the downhole tool 100 in this embodiment is coupled to the threaded pin end 203 of another downhole tool 209 (see
View 107 is a cross-sectional view of the integrated circuit 106 and the recess 105 and is depicted in
Referring now to
Referring now to
Referring now to
In the embodiment shown, the protective material 108 conforms to the dimensions of the recess 105 in order to provide additional structural security in the downhole tool 100 and protection from shocks and jolts to the integrated circuit 106. The protective material 108 may comprise any of a variety of materials including (but not limited to) epoxies; synthetic plastics; glues; clays; rubbers, foams, potting compounds; Teflon®, PEEK® and similar compounds; ceramics; and the like. For embodiments in which the integrated circuit 106 comprises RFID circuitry and other applications, the protective material 108 may be magnetically conductive in order to facilitate the transmission of electromagnetic communication to and from the integrated circuit 106. In some embodiments, it may also be desirable for the protective material 108 to be electrically insulating and/or high-temperature resistant.
The protective material 108 may permanently encapsulate the integrated circuit 106. Alternatively, the integrated circuit 106 may be pre-coated with a material such as silicon, an RTV (room temperature vulcanizing) rubber agent, a non-permanent conformal coating material, or other material before encapsulation by the protective material 108 to facilitate its extraction from the protective material 108 at a later time.
Referring now to
In some embodiments of the invention, measures may be taken to relieve pressure in the recess 105 if drilling mud, lubricants, and other downhole fluids become trapped within the recess 105 as the tool joint 600 is being made up. This high pressure may damage the integrated circuit 106 or displace it from the recess 105. One means of relieving downhole pressure in the recess 105 is disclosed in U.S. patent application Ser. No. 10/710,586, filed Jul. 22, 2004 in the name of Hall, et. al. (hereafter referred to as the '586 application) which is herein incorporated by reference for all that it discloses. The means described in the '586 application comprises a pressure equalization passageway that permits fluids under pressure in the mating threads 202, 102 of the tool joint 600 to flow between interior and exterior regions of tubular bodies 104 of the downhole tools 100, 209.
Referring now to
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One preferred system of inductive couplers for downhole data transmission is disclosed in U.S. Pat. No. 6,670,880 (hereafter referred to as the '880 patent) to Hall, et. al, which is herein incorporated by reference for all that it discloses. Other means of downhole data communication may be incorporated in the downhole network such as the systems disclosed in U.S. Pat. Nos. 6,688,396 and 6,641,434 to Floerke and Boyle, respectively; which are also herein incorporated by reference for all that they disclose.
A data swivel 803 located at the top of the tool string 804 may provide a communicatory interface between the rotating tool string 804 and stationary surface equipment 802. In this manner data may be transmitted from the surface equipment 802 through the data swivel 803 and throughout the tool string 804. Alternatively a wireless communication interface may be used between the tool string 804 and the surface equipment 802. In the embodiment shown, an RFID transmitter/receiver apparatus 805 is located at the surface and may query RFID circuitry in downhole tools 100, 209 as they are added to or removed from the tool string 804. In this way, an accurate record of which specific tools make up the tool string 804 at any time may be maintained. Also, if a communications problem were traced to a specific downhole tool 100, 209 in the tool string 804, identification information received by the RFID transmitter/receiver apparatus 805 may be used in a database to access specific information about the faulty tool downhole 100, 209 and help resolve the problem. The RFID transmitter/receiver apparatus 805 may be in communication with the surface equipment 802 or may be an independent entity.
In other embodiments, the surface equipment 802 may not need the RFID transmitter/receiver 805 to communicate with the circuitry disposed within the downhole tools 100, 209. The surface equipment 802 may be equipped to send a query directly through wired downhole tools 100, 209 in the network 800 to RFID circuitry as will be discussed in more detail in the description of
Referring now to
When a first inductive coupler 900 is mated to a second similar inductive coupler 900, magnetic flux passes from the first magnetically conductive electrically insulating trough to the second magnetically conductive electrically insulating trough according to the data signal in the first electrically conducting coil 901 and induces a similar data signal in the second electrically conducting coil 901.
The inductive coupler 900 comprises an integrated circuit 106 which is preferably an RFID circuit. The integrated circuit 106 may comprise an active RFID tag, a passive RFID tag, low-frequency RFID circuitry, high-frequency RFID circuitry, ultra-high frequency RFID circuitry, and combinations thereof. The integrated circuit 106 may be located in a gap between the first point 902 and the second point 905 of the electrically conducting coil 901. The integrated circuit 106, electrically conducting coil 901, and U-shaped fragments 903 may be encapsulated within a protective material 108 as disclosed in the description of
The integrated circuit 106 may be in electromagnetic communication with the electrically conducting coil 901 due to their close proximity to each other. The electrically conducting coil 901 may act as a very short-range radio antenna and transmit a signal that may be detected by RFID circuitry in the integrated circuit 106. Likewise, an identification signal transmitted by the RFID circuitry in the integrated circuit 106 may be detected by the electrically conducting coil 901 and transmitted throughout a downhole network 800. In this manner, surface equipment 802 and other network devices may communicate with the integrated circuit 106. Signals received from the integrated circuit 106 in the electrically conducting coil 901 of the inductive coupler 900 may require amplification by repeaters (not shown) situated along the downhole network 800.
Referring now to
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Mechanical seals created by the junction of primary mating surfaces 101, 201 and secondary mating surfaces 601, 208 may protect both the inductive couplers 900 and the integrated circuits 106 from downhole conditions.
Referring now to
Through the downhole network 800, the RFID transmitter/receiver 805 of the surface equipment 802 may be in electromagnetic communication with the integrated circuit 106.
Referring now to
Tool 209 may comprise an integrated RFID circuit 1406.
Still referring to
Through the downhole network 800, the RFID transmitter/receiver 805 of the surface equipment 802 may be in electromagnetic communication with the RFID integrated circuit 1406.
In other embodiments of the invention, a direct electrical contact coupler or a hybrid inductive/electrical coupler such as is disclosed in U.S. Pat. No. 6,641,434 to Boyle, et al may be substituted for the inductive coupler 900. Also U.S. Patent Publication No. 20050074988 discloses a direct connect system compatible with the present invention and is herein incorporated by reference for all that it discloses.
Referring now to
The RFID interrogation signals may be transmitted at first frequency while network data is transmitted at second frequency. In selected embodiments, a first series of RFIDs may respond to interrogation signals on a first frequency, while a second series of RFIDs may respond to interrogation signals on a second frequency. For example, it may be desirable to identify all of the downhole tools comprising network nodes. An interrogation signal may be sent on a frequency specific for those tools comprising network nodes and other RFIDs in communication with the downhole network will not respond.
The method 1600 further comprises the steps of transmitting 1630 an identification signal modulated with identification data from the identification circuitry to the surface equipment 802 and demodulating 1640 the identification data from the identification signal to identify the downhole tool 100. The identification data may be a serial number.
Referring now to
The method 1700 further comprises the downhole tool 100 receiving 1715 the interrogating signal from the downhole network 800 and transmitting 1720 the interrogating signal from an inductive coupler 900 to passive circuitry in a shoulder of the downhole tool 100. The passive circuitry is preferably an integrated circuit 106 that comprises RFID capabilities. The downhole tool 100 may receive 1715 the interrogating signal in the inductive coupler 900. The inductive coupler 900 may communicate wirelessly with the passive circuitry through an internal antenna in the passive circuitry. In other embodiments, the inductive coupler 900 may act as an external antenna for the passive circuitry and communicate with it through direct electrical communication. The passive circuitry may then transmit 1725 an identification signal to the inductive coupler 900 in the downhole tool 100. The identification signal may comprise identification information such as a serial number modulated on a sinusoidal electromagnetic signal.
The method further comprises the downhole tool 100 transmitting 1730 the identification signal to the surface equipment 802 through the downhole network 800. The surface equipment 802 may receive 1735 the identification signal from the downhole network 800 and demodulate 1740 the identification signal to retrieve the identification information and identify the downhole tool 100. The identification information on the identification signal may then permit the surface equipment 802 to access a database or other form of records to obtain information about the downhole tool 100.
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.
