1. Field of the Invention
The invention relates generally to the field of wellbore instruments and well logging methods. More specifically, the invention relates to systems and methods for operating electrically powered instruments in a well using a wired pipe string as a signal communication channel.
2. Background Art
Well logging instruments are devices configured to move through a wellbore drilled through subsurface rock formations. The devices include one or more sensors and other devices that measure various properties of the subsurface rock formations and/or perform certain mechanical acts on the formations, such as drilling or percussively obtaining samples of the rock formations, and withdrawing samples of connate fluid from the rock formations. Measurements of the properties of the rock formations made by the sensors may be recorded with respect to the instrument axial position (depth) within the wellbore as the instrument is moved along the wellbore. Such recording is referred to as a “well log.”
Well logging instruments can be conveyed along the wellbore by extending and withdrawing an armored electrical cable (“wireline”), wherein the instruments are coupled to the end of the wireline. Such conveyance relies on gravity to move the instruments into the wellbore. Extending and withdrawing the wireline may be performed using a winch or similar spooling device known in the art. However, gravity can only be used on substantially vertical wellbores. Those deviating from vertical require additional force to move through the wellbore.
There are several types of wireline instrument conveyance known in the art for the foregoing conditions. One conveyance technique includes coupling the wireline instruments to the end of a coiled tubing having a wireline disposed therein. The wireline instruments are extended into and withdrawn from the wellbore by extending and retracting the coiled tubing, respectively. A subset of such coiled tubing techniques includes preliminary conveyance of the wireline configurable well logging instruments to a selected depth in the wellbore using a threadedly coupled pipe “string.” See, for example, U.S. Pat. No. 5,433,276 issued to Martain et al. However, the use of coiled tubing with wireline instruments is costly and is inherently limited by the amount of pushing force capable with the coiled tubing. As a result, the use of coiled tubing is typically problematic in extended reach wells.
Another well logging instrument conveyance technique includes coupling wireline configurable well logging instruments to the end of a drill pipe or similar threadedly coupled pipe string. A wireline is coupled to the instruments using a “side entry sub” which provides a sealable passage from the exterior of the pipe string to the interior thereof. As the pipe string is extended into the wellbore, the wireline is extended by operating a conventional winch. An example of the foregoing is described in U.S. Pat. No. 6,092,416 issued to Halford et al. and assigned to the assignee of the present invention. However, this conveyance technique is frequently unreliable as the wireline is positioned in the annulus and subject to crushing, splicing or other damage. For example, the wireline may become pinched between the drill pipe and the casing or wellbore.
Additionally, the well logging instruments may be positioned at the end of a drill pipe without use of a wireline cable. In such circumstances, each well logging instrument is provided with a battery and memory to store the acquired data. As a result, the well logging instruments cannot communicate with the surface while downhole. In addition, the data acquired cannot be analyzed at the surface until the wireline instruments return to the surface. Without any communication with the surface, surface operators cannot be certain the instruments are operating correctly, cannot control the instruments while downhole, and the data cannot be analyzed until after the wireline instruments are removed from the wellbore.
Recently, a type of drill pipe has been developed that includes a signal communication channel. See, for example, U.S. Pat. No. 6,641,434 issued to Boyle et al. and assigned to the assignee of the present invention. Such drill pipe, known as wired drill pipe, has in particular provided substantially increased signal telemetry speed for use with LWD instruments over conventional LWD signal telemetry, which typically is performed by mud pressure modulation or by very low frequency electromagnetic signal transmission.
The foregoing wired drill pipe having a signal communication channel has not proven effective at transmitting electrical power from the surface to an instrument string disposed at a lower end of the pipe. In wireline conveyance of wellbore instrument, electrical power is transmitted from the surface to the instruments in the wellbore using one ore more insulated electrical conductors in the wireline cable. In MWD and LWD, electrical power may be provided by batteries, or by an electric generator operated by flow of fluid through the pipe. When wired pipe is used for signal telemetry, the amount of electrical power required by the instruments may be substantially reduced because the signal telemetry device used in MWD/LWD, typically a mud flow modulator, uses a substantial portion of the total electrical power used by the instruments in the bottom hole assembly.
What is needed is a system and method for pipe conveyance of wellbore instruments that includes substantial signal telemetry capability, and does not require the use of armored electrical cable for continuous transmission of electrical power to the instruments in the wellbore or signal communication from the instruments to the surface.
The invention generally relates to devices for conveying a wellbore instrument or a “string” of such instruments through a wellbore using a wired pipe string, or wired drill pipe string, for conveyance and data communication uphole and/or downhole. The instrument string may include an electrical generator, battery, generator, power storage module or “sub” for supplying electrical power to operate the instrument string and for providing signal or data telemetry to a signal communication channel associated with the wired pipe string. The wired pipe string may be assembled and disassembled in segments to effect conveyance through a wellbore in a manner known in the art for conveyance of any type of segmented or jointed pipe through a wellbore.
In some examples as explained below, an instrument or a string of such instruments that can otherwise be conveyed through a wellbore using armored electrical cable (“wireline instrument string”) can be coupled to one longitudinal end of a wired pipe string and extend into the wellbore below the end of the wired pipe string. Other examples can have the wireline instrument string partially or entirely disposed within an internal conduit or passage in the wired pipe string. The invention is equally applicable to any of the foregoing configurations.
In
The wired drill pipe string 20 may include one, or a plurality of coupled together wellbore instruments referred to as an instrument string 13 coupled to a lower end thereof. In the present example, the wellbore instrument string 13 may include various wireline configurable well logging instruments. As used in the present description, the term “wireline configurable well logging instrument” means a well logging or servicing instrument that can be conveyed through a wellbore using armored electrical cable (“wireline”) or plain wire rope or line (“slickline”). Wireline configurable well logging instruments are thus distinguishable from “logging while drilling” (“LWD”) instruments, which are configurable to be used during wellbore operations and form part of the pipe string itself. The purpose for coupling the wireline configurable logging instrument string 13 to the end of the wired pipe string 20 will be further explained below. LWD and related drill string instrumentation may also be used in addition to the wireline instrument string 13.
Several of the components disposed proximate the drilling unit 24 may be used to operate part of the system of the invention. These components will be explained with respect to their uses in drilling the wellbore to better enable understanding the invention, but it is to be understood that such components are used in wellbore operations other than drilling. Non-limiting examples of such other operations include “tripping”, “reaming”, “washing” and “circulating.” In drilling, the pipe string 20 may be used to turn and axially urge a drill bit (not shown) into the bottom of the wellbore 18 to increase its length (depth). During drilling of the wellbore 18, a pump 32 lifts drilling fluid (“mud”) 30 from a tank 28 or pit and discharges the drilling fluid 30 under pressure through a standpipe 34 and flexible conduit 35 or hose, through the top drive 26 and into an interior passage (not shown separately in
When the wellbore 18 has been drilled to a selected depth, the pipe string 20 may be withdrawn from the wellbore 18, and an adapter sub 12 and the well logging instrument string 13 may be coupled to the lower end of the pipe string 20. The pipe string 20 may then be reinserted into the wellbore 18 so that the instruments 13 may be moved through, for example, a highly inclined portion 18A of the wellbore 18 which would be difficult to access using armored electrical cable (“wireline”) to move the instruments 24. It is also known in the art to include a well logging instrument string within the pipe string, and cause the well logging instrument string to extend partially or completely out from the pipe string without the need to remove the pipe string from the wellbore. See, for example, U.S. Pat. No. 7,134,493 issued to Runia. Therefore, using the wireline instrument string according to the invention is not limited to prior withdrawal of the pipe string from the wellbore.
Advantageously with the use of pipes during well logging operations, in some examples the pump 32 may be operated to provide fluid flow to operate one or more turbines (explained below) in the well logging instrument string 13. The turbine(s) can provide power to operate certain devices in the well logging instrument string 13. As another example, the turbine(s) may be used to recharge batteries, fuel cell or other rechargeable power sources located either in a special power sub or in each individual instrument or tool.
In other examples, the wired pipe string 20 may be rotated to provide power to the well logging instrument string 13. For example, U.S. Pat. No. 7,537,051, which is hereby incorporated by reference in its entirety, discloses using rotation of the drill pipe to move a power generation element and induce an electrical current. The current generated in the '051 patent may be used to power the well logging instrument string 13 in an embodiment of the present invention. The current may also be used to recharge a battery or other rechargeable power source.
In yet another example, vibrational energy may be used to power the well logging instrument string 13, a rechargeable battery, and any other rechargeable power source. U.S. Pat. Nos. 4,518,888; 6,768,214; 7,199,480; 7,208,845; and 7,242,103 all discloses a system and/or method of converting vibrational energy into electrical power. Still in other examples, batteries may be used to operate the instrument string 13. Any types of batteries may be used as will be appreciated by those of ordinary skill in the art, including
In a non-preferred embodiment, power may be transmitted downhole through the wired drill string 20, and, in such an embodiment, may be amplified or used to power or recharge a battery in the special power sub to provide power to the instruments. The foregoing examples of power provision may be used individually or in any combination.
As the well logging instrument string 13 is moved along the wellbore 18 by moving the pipe string 20 as explained above, signals detected by various sensors, non-limiting examples of which may include an induction resistivity instrument 16, a gamma ray sensor 14 and a formation fluid sample taking device 10 (which may include a fluid pressure sensor (not shown separately) are selected to be conveyed to a telemetry transceiver (
The functions performed by the adapter sub 12 may include providing a mechanical coupling (explained below) between the lowermost threaded connection on the pipe string 20 and an uppermost connection on the well logging instruments 13. For example, the mechanical coupling may include a change in threads or pipe size from one end of the adapter sub 12 to the other end of the adapter sub 12. The adapter sub 12 may also include one or more devices (explained below) for producing electrical power to operate various parts of the well logging instruments 13. Finally, the adapter sub 12 may include signal processing and recording devices (explained below with reference to
It will be appreciated by those skilled in the art that in other examples the top drive 26 may be substituted by a swivel, kelly, kelly bushing and rotary table (none shown in
The digital data handling rate (bandwidth) of wired pipe strings such as the one described in the Boyle et al. '434 patent may be about 1 million bits per second. As is known in the art, typical wireline configurable well logging instrument strings can generate signals at large multiples of the bandwidth of typical wired pipe strings. Accordingly, it is desirable to use the available wired pipe string bandwidth to communicate to the surface those signals from the well logging instrument string (13 in
An example signal processing and recording unit disposed in or associated with the adapter sub 12 that can perform the foregoing telemetry conversion and formatting is shown in block diagram form in
The command decoder 82 may transmit instructions to change the data sent over the wired pipe string 20 to an intermediate telemetry transceiver 86. The intermediate telemetry transceiver 86 receives well logging instrument measurements from the instrument string by signal connection to a well logging instrument telemetry transceiver 88 in the instrument string 13. The well logging instrument telemetry transceiver 88 may be the same type as used in any wireline configurable well logging instrument string, and is preferably configured to transmit signals over an armored electrical cable (“wireline”) when the instrument string is deployed on a wireline. In the present example, all or substantially all well logging instrument signals that would be transmitted over the wireline if so connected may be communicated to the intermediate telemetry transceiver 86. Depending on the instruction from the surface some of the signals are communicated to the WDP telemetry transceiver 80 for communication over the wired pipe string 20. Remaining or all well logging instrument signals may be communicated to a data storage device 84 such as a solid state memory or hard drive. The data storage device 84 may also receive and store the same signals that are transmitted to the surface over the wired pipe string. The foregoing components, including the WDP telemetry 80, the data storage 84, the command decoder 82 and the intermediate telemetry 86 may be enclosed in the adapter sub 12 in some examples. In other examples, the foregoing components may be enclosed in a separate housing (not shown) that is itself coupled to the adapter sub 12 and to the instrument string 13.
One example of the adapter sub is shown in more detail in
Another example of an adapter sub 12 is shown in cross sectional view in
In other examples, the wireline well logging instrument string may be disposed partially or entirely inside the passage in the pipe string. Two such examples are shown in
The adapter sub 12 may be coupled to a power converter module 200 that converts the output of a battery 202 into a form suitable for operating the instrument string 13. In the example of
The example shown in
Another example adapter sub is shown in
The relative rotation between the pipe string 20 and the adapter sub 12 requires a signal communication link between the instrument string 13 and the communication channel in the pipe string 20 that may be operative through such relative rotation. In the present example, an induction coil 334 may be disposed in the adapter sub 12 longitudinally proximate a corresponding induction coil 332 in the pipe string 20. Such proximate induction coils 332, 334 may provide signal communication between the instrument string 13 and the pipe string 20. An inductive coupling such as the one described in U.S. Pat. Nos. 5,521,592 and 4,806,928 issued to Veneruso and assigned to the assignee of the present invention may be used in the pipe string and the adapter sub to effect signal communication.
Another example of the adapter sub 12 is shown in cross section in
The collar 150 may define an interior chamber 156 in which may be contained some or all of the active components of the generator portion of the sub 12. The chamber 156 may be enclosed, sealed and maintained substantially at surface atmospheric pressure by inserting a resilient metal tube 161 into an interior passage 148 in the collar 150. The tube 161 may be sealed against the interior of the collar 150 by o-rings 163 or other sealing elements. The tube 161 should have sufficient strength to resist bursting by reason of the pressure of mud (30 in
In the present example, the chamber 156 may include therein one or more piezoelectric transducers, shown at 158 and 146. The one or more piezoelectric transducers 158, 146 are arranged to undergo stress (and consequently develop a voltage thereacross) as a result of certain types of vibrations, such as lateral, axial or torsional, induced in the drill string (20 in
A second one of the piezoelectric transducers, shown at 146, may be made from a plurality of substantially planar piezoelectric crystals polarized in the direction of their thickness. The second transducer 146 may be coupled on one face to a metal protective shield 144, and the shield 144 placed in contact with an exterior surface of the tube 161 that is adjacent to the interior passage 148 for flow of drilling fluid (30 in
A third piezoelectric transducer 140 may be enclosed in elastomer 142 such as rubber to exclude fluid therefrom while enabling the transducer 140 to remain sensitive to pressure variations in the ambient environment. The third transducer 140 may be disposed in a recess 141 formed on the exterior of the collar 150. The third transducer 140 may be electrically coupled to circuits in the chamber 156 using a pressure-sealed electrical feedthrough 165 of types well known in the art to exclude fluid from entering the chamber 156. Arranged as shown in
In some examples, the piezoelectric materials used to make the transducers may be crystals or ceramics with high dielectric constants, high sensitivity, and high electro-mechanical constants. Examples of the foregoing include lead zirconate titanate (PZT) type ceramics with extremely high dielectric constant and high coupling coefficients, and piezoelectric single crystals lead magnesium niobate-lead titanate (PMN-PT) and lead zirconate niobate-lead titanate (PZN-PT), which both have extremely high charge constants, high electro-mechanical coupling coefficients and high dielectric constants.
The electrical output of each of the transducers 158, 146, 140 may be coupled to power conditioning circuits 160 disposed within the chamber 156. The power conditioning circuits 160 may include suitable switching, rectification and energy storage elements (e.g., capacitors, not shown separately) so that electric power generated by the transducers is stored and made available for other components of the drill string. A power transmitter 162 may be used to convert electric power stored in the storage elements (e.g., a capacitor bank—not shown) in the power conditioning circuits 160 to suitable alternating current for transmission using the electromagnetic coupling 164. The power transmitter 162 may be omitted if the electric power is communicated directly through a galvanic electrode (not shown). The example transducers shown in
The invention as explained above may be used in conjunction with a number of other drilling and measurement devices known in the art. Non-limiting examples of such other devices may include the following. The wireline configurable well logging instruments may be inserted into a sleeve or a drill collar to protect them from being damaged during rotation and/or lateral movement, and can enable fluid pumped from the surface to flow around them for cooling purposes.
A sleeve or drill collar may cover less than the entire string of well logging instruments, thus allowing sections of the instrument string to come into direct contact with the formations (11 in
A drill bit may be added at the bottom of the instrument string to allow drilling to continue while logging or between logging/sampling operations in conjunction with a drilling motor. The motor and/or a rotary steerable directional drilling system may be included between the drill bit and the well logging instruments to improve drilling efficiency and allow controlling the trajectory of the wellbore (18 in
Logging while drilling (“LWD”) and/or measurement while drilling (“MWD”) instruments known in the art may be included at any location in the wired pipe string (20 in
Stabilizers, reamers or wear bands may be placed on the foregoing sleeve or on a drill collar for directional control, wellbore conditioning, hole opening or other reasons.
Existing measurement while drilling telemetry technology (mud pressure modulation telemetry) may be used as two way communication with the surface instead of wired drill pipe or as a contingency to the failure of the wired drill pipe.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.