The present disclosure relates generally to wellbore operations and, more particularly, to a sleeve assembly for a downhole logging tool.
During drilling operations for the extraction of hydrocarbons, a variety of recording and transmission techniques are used to provide or record data downhole, for example, from the vicinity of a drill bit. Measurements of the surrounding subterranean formations may be made throughout drilling operations using downhole measurement and logging tools, such as measurement-while-drilling (MWD) and/or logging-while-drilling (LWD) tools, which help characterize the formations and aid in making operational decisions. Wellbore logging tools make measurements that may be used to determine the electrical resistivity (or its inverse, conductivity) of the formations being penetrated, where the electrical resistivity indicates various features of the formations. Those measurements may be taken using one or more antennas coupled to, within or otherwise associated with the wellbore logging tools.
Logging tool antennas are often formed by positioning coil windings about an axial section of the logging tool, such as a drill collar. A ferrite material or “ferrites” are sometimes positioned beneath the coil windings to increase the efficiency and/or sensitivity of the antenna.
The ferrites facilitate a higher magnetic permeability path (for example, a flux conduit) for the magnetic field generated by the coil windings, and help shield the coil windings from the drill collar and associated losses (for example, eddy currents generated on the drill collar). The antenna must be protected from the harsh downhole environment. Generally, the antennas are protected by positioning a sleeve around the antennas to protect the antennas from abrasion and erosion while the downhole logging tool traverses the wellbore. As the sleeve interferes with the operation of the antennas, slots are formed in the sleeve to provide a dipole angle for the electromagnetic field of the antennas to penetrate the formation or object of interest. However, debris, fluids or other harmful materials could penetrate the slots and damage the antennas. Typically, a non-conductive inner sleeve is inserted into the outer sleeve to cover the slots and protect the antennas or the slots could be filled with an epoxy. Both solutions still allowed for some erosion and exposure of the antennas to the downhole environment. Both solutions increase costs, wear and tear and decrease reliability.
The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications alterations combinations, and equivalents in form and function, without departing from the scope of this disclosure.
The present disclosure relates generally to wellbore operations and, more particularly, to a protective sleeve assembly for antennas of a wellbore logging tools used in hydrocarbon drilling operations.
Downhole environments may have harsh operating conditions such as abrasive and erosive fluids including liquids, solid particles, and other debris. During downhole logging operations, for example, measurement while drilling (MWD) and logging while drilling (LWD) operations, a downhole tool that includes an antenna may include sections that include an antenna for receiving data related to a formation of interest or any other object. These antennas are susceptible to damage and catastrophic failure due to the harsh downhole operating conditions. Thus, these antennas must be protected while at the same time provided with the ability to obtain the desired measurements or data.
The antenna may be protected by an outer sleeve. To provide adequate protection from the downhole operating conditions, the outer sleeve is generally constructed using a metallic material that interferes with the operation of the antenna. To provide for proper operation of the antenna, the outer sleeve comprises one or more slots that allow the antenna to transmit and receive signals to and from the downhole tool. However, the slots allow for erosion and abrasion, for example, from a downhole fluid. Typically, a non-conductive inner sleeve is inserted or press-fit into the outer sleeve to provide protection for the antenna and the slots are filled with a non-conductive material. Filling the slots with a non-conductive material protects the antenna from the downhole operating conditions but may not be adequate as the non-conductive material is also susceptible to erosion and abrasion and typically does not bind sufficiently to the inner sleeve. For example, the non-conductive material may comprise an epoxy that breaks, cracks or otherwise weakens during a downhole operation which reduces the life of the outer sleeve, the inner sleeve, the antenna or any combination thereof and requires expensive and time-consuming repair or replacement. Further, the inner sleeve necessarily reduces the available space within the outer sleeve for the antenna and necessary corresponding components. Insertion of the inner sleeve also creates a gap between the inner sleeve and the outer sleeve. Repairing the outer sleeve and the inner sleeve with the epoxy filled slots may be time-consuming, expensive and laborious and may result in delays for completing the downhole operation.
According to one or more embodiments, a composite insert may be disposed or positioned within the slot that provides sufficient boding to the outer sleeve to protect the internal components of the outer sleeve, such as the antenna. A composite insert does not have gaps between the outer sleeve and the insert and is not as susceptible to the downhole operating conditions as the previously used non-conductive material that was injected into the slots. The composite insert provides a reliable and cost-efficient protection for the components of the outer sleeve.
The drilling system 100 may include a derrick 108 supported by the drilling platform 102 and having a traveling block 110 for raising and lowering a drill string 112. A kelly 114 may support the drill string 112 as it is lowered through a rotary table 116. A drill bit 118 may be coupled to the drill string 112 and driven by a downhole motor and/or by rotation of the drill string 112 by the rotary table 116. As the drill bit 118 rotates, it creates the wellbore 104, which penetrates the subterranean formations 106. A pump 120 may circulate drilling fluid through a feed pipe 122 and the kelly 114, downhole through the interior of drill string 112, through orifices in the drill bit 118, back to the surface via the annulus defined around drill string 112, and into a retention pit 124. The drilling fluid cools the drill bit 118 during operation and transports cuttings from the wellbore 104 into the retention pit 124.
The drilling system 100 may further include a bottom hole assembly (BHA) coupled to the drill string 112 near the drill bit 118. The BHA may comprise various downhole measurement tools such as, but not limited to, measurement-while-drilling (MWD) and logging-while-drilling (LWD) tools, which may be configured to take downhole measurements of drilling conditions. The MWD and LWD tools may include at least one wellbore logging tool 126, which may comprise one or more antennas capable of receiving and/or transmitting one or more electromagnetic (EM) signals that are axially spaced along the length of the wellbore logging tool 126. The one or more antennas are protected by a protective sleeve assembly as discussed below with respect to
As the drill bit 118 extends the wellbore 104 through the formations 106, the wellbore logging tool 126 may continuously or intermittently collect azimuthally-sensitive measurements relating to the resistivity of the formations 106, for example, how strongly the formations 106 opposes a flow of electric current. The wellbore logging tool 126 and other sensors of the MWD and LWD tools may be communicably coupled to a telemetry module 128 used to transfer measurements and signals from the BHA to a surface receiver (not shown) and/or to receive commands from the surface receiver. The telemetry module 128 may encompass any known means of downhole communication including, but not limited to, a mud pulse telemetry system, an acoustic telemetry system, a wired communications system, a wireless communications system, or any combination thereof. In certain embodiments, some or all of the measurements taken at the wellbore logging tool 126 may also be stored within the wellbore logging tool 126 or the telemetry module 128 for later retrieval at the surface upon retracting the drill string 112.
At various times during the drilling process, the drill string 112 may be removed from the wellbore 104, as shown in
The bobbin 306 may structurally comprise a high temperature plastic, a thermoplastic, a polymer (for example, polyimide), a ceramic, or an epoxy material, but could alternatively be made of a variety of other non-magnetic, electrically insulating/non-conductive materials. The bobbin 306 can be fabricated, for example, by additive manufacturing (for example, 3D printing), molding, injection molding, machining, or other known manufacturing processes.
The coil 308 can include any number of consecutive “turns” (for example, windings of the coil 308) about the bobbin 306, but typically will include at least a plurality (for example, two or more) consecutive full turns, with each full turn extending 360 degrees about the bobbin 306. In some embodiments, a pathway for receiving the coil 308 may be formed along the outer surface of the bobbin 306. For example, one or more grooves may be defined in the outer surface of the bobbin 306 to receive and seat the coil 308. In other embodiments, however, the outer surface of the bobbin 306 may be smooth or even. The coil 308 can be concentric or eccentric relative to a central axis 310 of the tool mandrel 304.
As illustrated, the turns or windings of the coil 308 extend about the bobbin 306 at an angle 312 offset from the central axis 310. As a result, the antenna assembly 302 may be characterized and otherwise referred to as an “antenna,” “tilted coil” or “directional” antenna. In the illustrated embodiment, the angle 312 is 45°, by way of example, and could alternatively be any angle offset from the central axis 310, without departing from the scope of the disclosure.
The sleeve assembly 350 comprises one or more slots 358 distributed, formed, positioned or disposed about any one or more portions of the sleeve assembly 350. In one or more embodiments, the sleeve assembly 350 may comprise one or more slots 358 distributed circumferentially at one or more angles as illustrated in the isometric view 500 of the sleeve assembly 350 of
A non-conductive insert 356 may be disposed or positioned in any one or more of the one or more slots 358. The non-conductive insert 356 may comprise a composite material. The non-conductive insert 358 comprises a material that does not substantially interfere with the functioning or operation of an antenna, for example, as illustrated in
Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.
This application claims priority from U.S. application Ser. No. 16/400,573 entitled “Molded Composite Inner Liner for Metallic Sleeves,” filed on May 1, 2019, which claims priority from U.S. Provisional Application Ser. No. 62/683,803 entitled “Molded Composite Inner Liner for Metallic Sleeves,” filed on Jun. 12, 2018, the entire disclosures of which are incorporated herein by reference.
Number | Date | Country | |
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62683803 | Jun 2018 | US |
Number | Date | Country | |
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Parent | 16400573 | May 2019 | US |
Child | 17713288 | US |