Abstract: A collar-mountable antenna for transmitting and receiving signals in a downhole environment, in at least some embodiments, comprises a bobbin having an inner surface and an outer surface, each of the inner and outer surfaces defining multiple slots, conductive wire disposed within the multiple slots on the outer surface of the bobbin, and ferrite disposed within the multiple slots on the inner surface of the bobbin.

Abstract: An antenna assembly for wellbore logging tools is provided. The antenna assembly includes a coil wrapped about an outer surface of a bobbin positioned within a saddle of a tool mandrel. The antenna assembly also includes an inner sleeve positioned on an outer surface of the tool mandrel within the saddle, the inner sleeve being interposed between the coil and the tool mandrel. The antenna assembly also includes a plurality of ferrite channels formed within a groove defined in an inner surface of the inner sleeve, in which the plurality of ferrite channels being laterally separated by a plurality of dividers formed in the groove. The antenna assembly also includes a plurality of ferrites disposed within respective ones of the plurality of ferrite channels.

Abstract: An antenna assembly includes a bobbin positionable about an outer surface of a tool mandrel, and a coil wrapped about an outer bobbin surface of the bobbin and extending longitudinally along at least a portion of the outer bobbin surface. A plurality of ferrites are positioned within a groove defined in the outer surface of the tool mandrel, and the plurality of ferrites extend circumferentially about the outer surface and interpose the tool mandrel and the coil.

Abstract: An antenna assembly includes a bobbin positionable about an outer surface of a tool mandrel and providing an outer bobbin surface. A coil is wrapped about and extends longitudinally along at least a portion of the outer bobbin surface. An inner sleeve interposes the bobbin and the tool mandrel and receives a plurality of ferrites that interpose the tool mandrel and the coil.

Abstract: An antenna assembly includes a bobbin positionable about an outer surface of a tool mandrel, and a coil wrapped about an outer bobbin surface of the bobbin and extending longitudinally along at least a portion of the outer bobbin surface. A plurality of ferrites are positioned within a groove defined in the outer surface of the tool mandrel, and the plurality of ferrites extend circumferentially about the outer surface and interpose the tool mandrel and the coil.

Abstract: Mechanisms for induction-based resistivity measurements can be provided for use in geo-steering in a drilling operations environment. An antenna assembly can provide effective protection for antenna sections without hindering propagation of electromagnetic signals. The antenna assembly can include a bobbin disposed about a collar of a tool string; an antenna disposed on an outer surface of the bobbin; an outer adhesive layer covering the antenna and at least a portion of the bobbin; and a protective layer disposed against the outer adhesive layer; wherein the outer adhesive layer fills a space radially between the bobbin and the protective layer.

Abstract: A collar-mountable antenna for transmitting and receiving signals in a downhole environment, in at least some embodiments, comprises a bobbin having an inner surface and an outer surface, each of the inner and outer surfaces defining multiple slots, conductive wire disposed within the multiple slots on the outer surface of the bobbin, and ferrite disposed within the multiple slots on the inner surface of the bobbin.

Abstract: An antenna assembly includes a bobbin positionable about an outer surface of a tool mandrel, and a coil wrapped about an outer bobbin surface of the bobbin and extending longitudinally along at least a portion of the outer bobbin surface. A plurality of ferrites are positioned within a groove defined in the outer surface of the tool mandrel, and the plurality of ferrites extend circumferentially about the outer surface and interpose the tool mandrel and the coil.

Abstract: An antenna assembly includes a bobbin positionable about an outer surface of a tool mandrel and providing an outer bobbin surface. A coil is wrapped about and extends longitudinally along at least a portion of the outer bobbin surface. An inner sleeve interposes the bobbin and the tool mandrel and receives a plurality of ferrites that interpose the tool mandrel and the coil.

Abstract: A system to protect a downhole antenna from fluid penetration, in some embodiments, comprises a collar; a bobbin antenna, mounted on the collar, including multiple coil slots on an outer surface of the bobbin antenna and including one or more intra-bobbin wireways between at least one of the coil slots and an outlet of the bobbin antenna; and a collar wireway that is dedicated to the bobbin antenna.