The present invention relates to downhole drilling, specifically downhole drilling technology for oil, gas, geothermal and horizontal drilling. More specifically, the present invention relates to downhole drill string components and connections between components. Also, the present invention relates to communication between uphole and downhole components.
Downhole instruments may be used to analyze downhole formation characteristics such as porosity or density or to locate resource deposits in a formation. The assembly of a drill string comprising a plurality of instruments often involves individually electrically connecting the instruments. In many cases, each instrument must be wired separately. Downhole drill strings with multiple instruments can comprise a multiplicity of wires, often increasing the complexity of wiring downhole instruments to the desired location within the drill string. The overall efficiency of this method of wiring may be inferior to an apparatus that comprises a reduction of the number of wires involved. Additionally, the ability to simultaneously electrically connect the plurality of instruments to a power source, processor or downhole network may reduce the assembly time.
A common practice in the art involves exciting one instrument often circumferentially wrapped around the drill string and used to gather borehole data downhole. Exciting this single instrument generally does not allow for only a portion of a borehole to be analyzed to determine downhole characteristics.
U.S. patent application Ser. No. 11/776,447 to Snyder, which is herein incorporated by reference for all that it contains, discloses in one aspect an induction resistivity tool incorporated into a downhole tool string comprising an outer wall of a downhole component comprising an outer diameter and at least one induction transmitter assembly disposed along the outer diameter. The at least one transmitter assembly comprises at least one induction transmitter coil wound about at least one core. The at least one transmitter coil is adapted to project an induction signal outward from the outer wall when the at least one transmitter coil is carrying an electrical current. The transmitter assembly is adapted to create electromagnetic fields that originate the induction signal from outside the outer wall and substantially prevent the signal from entering the outer wall.
U.S. Pat. No. 5,045,795 to Gianzero, et al, which is herein incorporated by reference for all it contains, discloses a coil array which is installed on a MWD drill collar for use in a resistivity logging system. The drill collar is provided with upper and lower coil support rings. These are toroids which support individual coil segments, and are connected by suitable magnetic shorting bars. The coil segments and shorting bars inscribe a specified solid angle or azimuthal extent. By connecting the outputs of the several coils through a combining circuit, the coils on a single coil form can be connected in series additive, or subtractive relationship. Through the use of two such coil forms with aligned coils on each, an azimuthally oriented window is thereby defined. By proper switching multiple azimuthally oriented windows can be made operative so that there is an azimuthal orientation to the current flow pattern relative to the MWD resistivity logging tool.
In one aspect of the invention a downhole drill string component comprises a substantially cylindrical cage. The cage has a hollow bore, with an inner diameter and an outer diameter. The inner diameter of the cage is slideably connectable to a mandrel. A stab connection originates from one end of the cage. A plurality of downhole drill string instruments is circumferentially disposed around the outer diameter of the cage.
In several different embodiments of the present invention the plurality of downhole drill string instruments may be induction receivers, induction transmitters, Halbach arrays, batteries, nuclear tools, acoustic tools, similar downhole instruments known in the art, or any combination of such instruments. The cage may comprise a stab connection dock adapted to receive a stab connection on the opposite end from the stab connection, thus allowing for several embodiments of the present invention to be interconnected, directly or with other elements in between.
The cage may comprise a shell disposed circumferentially and at least partially along an inner cylinder that sits intermediate the downhole drill string instruments and the inner cylinder. The shell may have a plurality of recesses adapted to receive downhole drill string instruments. The shell may be segmented and the segments may be joined through a joining mechanism. The joining mechanism may comprise bolts, nuts, latches, screws, clips, hinges, adhesives, metallic bonding agents, welds, pins, other joining elements known in the art or combinations thereof. The cage may have a seal on either end that may act to restrict access of the drilling fluid into certain areas.
The cage may comprise an alignment key proximate the stab connection to protect the stab connection while it is being connected to a stab connection dock. The cage may also comprise a plurality of grooves disposed circumferentially around the cage that match with a plurality of rods on a stab connection dock or other downhole component. These grooves and rods may provide torsional strength and further protect the stab connection.
The stab connection may electrically communicate with a multiplexor, may be uniquely addressable, and may comprise a processing unit.
a is a perspective diagram of an embodiment of a cage.
b is a cross-sectional diagram of an embodiment of an outer cover.
a is a perspective diagram of another embodiment of a cage.
b is a perspective diagram of another embodiment of a cage.
c is a perspective diagram of another embodiment of a cage.
d is a perspective diagram of another embodiment of a cage.
a is a cross-sectional diagram of a downhole tool string component.
b is a cross-sectional diagram of a downhole tool string component.
c is a cross-sectional diagram of a downhole tool string component.
d is a cross-sectional diagram of a downhole tool string component.
a is a cross-sectional diagram of a downhole tool string component.
b is a cross-sectional diagram of a downhole tool string component.
In one aspect of the invention, the tool string component 201 may comprise an induction transmitter 210 and a plurality of induction receivers 211. The receivers 211 may be placed in a variety of orientations with respect to each other and to the transmitter 210. The induction transmitter 210 is adapted to send an induction signal into the formation, which generates a formation induction field surrounding the well bore. The induction receivers 211 are adapted to sense various attributes of the induction field in the formation. These attributes may include among others, some or all of the following: frequency, amplitude, or phase. The transmitter and the receivers may be powered by batteries, a turbine generator or from the downhole network. The receivers may also be passive. In some embodiments, there may be several induction transmitters located along the length of the tool string component 201. The transmitter 210 and receivers 211 may communicate with the network through a multiplexor 626 (See
a is a perspective diagram of an embodiment of a cage 200. The cage 200 may comprise a stab connection 300 adapted to electrically connect the cage with another downhole drill string component 201. It is believed that a cage 200 comprising a stab connection 300 on a downhole drill string component 201 may expedite the assembly process of the drill string 100. A stab connection 300 may also allow the drill string 100 to be assembled by placing multiple cages 200 onto a mandrel 202 in any order. In the event of damage to a downhole drill string instrument 322, the cage 200 may be removed from the drill string 100 for inspection and/or replacement by sliding it along the mandrel 202.
The stab connection 300 may connect with another component through a dock 510 (See
The stab connection 300 may electrically connect to a multiplexor 626. The multiplexor 626 may comprise more inputs than outputs. The downhole drill string instrument 322 may comprise an induction receiver, induction transmitter, Halbach array, battery, acoustic tool, and/or nuclear tool. Each instrument 322 may be independently excitable. Independently excitable instruments 322 may focus an induction field (as in a resistivity tool) or signal (as in a nuclear or sonic tool for example) into only a portion of the formation 105 adjacent to the excitable instruments while the remaining portion of the formation 105 is minimally affected or not affected at all. Furthermore it is believed that the ability to concentrate the field in portions of the formation 105 adjacent the bore hole 102 will allow for directional measurements of the formation 105.
The cage 200 may also comprise a shell 320 circumferentially disposed exterior an inner cylinder 1010 and along at least a portion of the length of the cage 200. The shell 320 may comprise a plurality of recesses 321 adapted to house the plurality of instruments 322. Each recess within the plurality of recesses 321 may comprise at least one wire from the plurality of wires 301 connectable to the instrument 322.
The shell 320 may be segmented. The shell 320 may be mounted onto the inner cylinder 1010 through a joining mechanism which may comprise bolts, nuts, latches, screws, clips, hinges, adhesives, metallic bonding agents, welds, pins, other joining elements known in the art or combinations thereof. The shell 320 may also be spring loaded to snap onto the inner cylinder 1010. Segmenting the shell 320 may lead to easy removal from and assembly onto the inner cylinder 1010.
b is a cross-sectional diagram of an embodiment of an outer cover 380. The cage 200 may comprise a plurality of grooves 340 disposed circumferentially around the cage 200 and sized to accept a plurality of rods 341 in each groove within the plurality of grooves 340. The plurality of grooves 340 and plurality of rods 341 may limit the rotation of the cage with respect to the downhole drill string 100 by restricting the rotation of the cage 200 with respect to the outer cover 380. The plurality of grooves 340 and plurality of rods 341 may also bear a majority of the load exerted on the drill string while downhole.
In various embodiments, two or more cages 200 of varying purpose (i.e. nuclear, resistivity, power, etc.) and comprising processor units 420 may be stacked within a drill string 100. A signal sent downhole by a downhole network or similar means may call for the operation of a particular cage 200 and may be picked up by the processor unit 420 of that particular cage 200. Stacking the cages 200 may not affect the addressability of each cage 200, no matter the quantity or arrangement of cages 200. Downhole programming may be unnecessary if each cage 200 has its own uniquely identifiable processor unit 420 and thus may be placed on the drill string 100 in any order and called on by surface equipment 150 to perform various functions.
a-d show several embodiments of cage 200 comprising various downhole instruments 322.
The cage 200 may also comprise a seal 701 which may restrict the access of drilling fluid into certain areas. The seal 701 may comprise a ring, band of rubber, washer, foam or combinations thereof. Seals 701 may be mounted on the cage 200 near the first end 302 and/or second end 303.
a-d are cross-sectional views of an embodiment of a cage 200 comprising individually excitable instruments 322. In some embodiments, these instruments 322 may be excited at once, in pairs, in groups, or individually.
In some applications it may be desirable to analyze only a portion of the formation 105 by exciting individual instruments 322. Where accuracy is critical the drill string 100 may be stopped while instruments 322 may be individually activated. Additionally, individual instruments 322 may be activated while the drill string 100 rotates. The instruments 322 may be activated in a number of different orders. The activation orders may include but are not limited to the orders depicted in
a and 9b depict different embodiments of induction receivers 211. The induction receivers 211 may be independently excitable. The induction receivers 211 may also be tunable such that a virtual receiver 900 may be created. A virtual receiver 900 may be created when two adjacent induction receivers 211 adjust their power such that a virtual receiver 900 can be modeled as being positioned between the two induction receivers 211.
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.
This application is a continuation-in-part of U.S. patent application Ser. No. 12/341,771 filed on Dec. 22, 2008 and entitled ‘Downhole Induction Resistivity Tool’ which is a continuation-in-part of U.S. patent application Ser. No. 11/776,447 filed on Jul. 11, 2007 and entitled ‘Externally Guided and Directed Field Induction Resistivity Tool’ which claims priority to Provisional U.S. Patent Application No. 60/914,619 filed on Apr. 27, 2007 and entitled ‘Resistivity Tool.’ This application is also a continuation-in-part of U.S. patent application Ser. Nos. 11/676,494; 11/687,891; 61/073,190. All of the above mentioned references are herein incorporated by reference for all that they contain.
Number | Date | Country | |
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60914619 | Apr 2007 | US | |
61073190 | Jun 2008 | US |
Number | Date | Country | |
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Parent | 12341771 | Dec 2008 | US |
Child | 12405880 | US | |
Parent | 11776447 | Jul 2007 | US |
Child | 12341771 | US | |
Parent | 11676494 | Feb 2007 | US |
Child | 11776447 | US | |
Parent | 11687891 | Mar 2007 | US |
Child | 11676494 | US |