Abstract: A dual transformer design, each transformer having at least a primary winding and a secondary winding disposed on a core means, wherein the core means is circumferentially disposed about an inner housing means, and the whole structure located within an outer housing. The primary winding of one transformer of said pair of transformers is electrically coupled to the primary winding of the other in a manner such as to cause induced eddy currents from one transformer to be of a magnitude and direction so as to substantially cancel the induced eddy currents from the other transformer.

Abstract: The invention relates to an apparatus for receiving downhole acoustic signals, processing the signals into electric signals, then transmitting the signals wirelessly to a remote above-surface monitoring station. The apparatus is mountable to an above-surface rotatable component used in borehole application. The apparatus includes an instrument housing, and a clamping assembly attached to the housing and having sufficient length and flexibility to enable the apparatus to surround the perimeter of the rotatable component.

Abstract: In a subassembly electrical isolation connector for interconnecting sections of a tubular drill rod, the subassembly having an electrically insulated connector for and between spaced-apart connector sections to transmit drilling forces therethrough, the use of a sealing membrane for sealing an insulated spacing in the electrically insulated connector to prevent ingress of pressurized drilling mud into the connector and shorting out said spaced-apart sections of the connector, the sealing membrane overlapping said connector sections as a continuous sleeve and having at least its sleeve ends sealed to respective portions of the connector sections to thereby activate the sealing membrane.

Abstract: In a subassembly electrical isolation connector for interconnecting sections of a tubular drill rod, said subassembly having an electrically insulated connector for and between spaced-apart connector sections to transmit drilling forces therethrough,

Abstract: A drill string section for use in making up a drill string for oil and gas drilling carries instrumentation for measurement and logging while drilling. The instrumentation includes a dynamic pressure device for measuring drill string bore pressure of incoming pressurized fluid and drill string annular pressure of returned pressurized fluid. The drill string section comprises a length of drill string pipe having a bore defined by an inner surface of a wall which has an outer surface. The instrumentation is provided in an elongate cylindrical tool shell. The outer surface of the tool shell has spaced apart seals which engage the inside surface of a cylindrical landing sleeve in the pipe bore. The seals are located in the sleeve on either side of communicating port(s) in the drill pipe wall, forming a leak tight annular region that eventually communicates through appropriate ports to a pressure transducer.

Abstract: A subassembly electrical isolation connector for interconnecting adjacent tubular drill rods of a drilling system used in drilling bore holes in earth formations electrically isolates the inner connection of the drill rods. The connector comprises a housing, a mandrel, a connector for connecting the housing to a first tubular drill rod, a connector for connecting a mandrel to a second tubular drill rod and a device for interconnecting the housing and the mandrel in a manner to electrically isolate the housing from the mandrel with the housing overlapping at least a portion of the mandrel. The housing has an isolated end which is electrically isolated from the mandrel and the connector for connecting the mandrel to a second tubular drill rod. Such arrangement provides enhanced strength to resist bending moments along the connector and resisting drilling forces.

Abstract: An antenna for use with portable duplex radio transceivers, such as those found in hand-held cellular telephones, which includes a pair of co-planar radiating patch elements elevated above a conductive surface by a conductive bar. The surface and bar define a reference ground plane which inherently isolates the patches. The patches are shaped so that they operate in a desired frequency band as well as band-pass filters--one of the patches is tuned to the transmit band and serves a transmit structure, and the other patch is tuned to the receive band and serves as a receive structure. Switching devices such as positive-intrinsic negative (PIN) diodes can be disposed along the space between the patches and the ground plane to allow each structure to be tuned. The antenna is efficient, because of inherent isolation between the receive and transmit patches, and eases the front end filtering functions traditionally performed by a duplexer. It can be completely enclosed within the chassis of a hand-held telephone.

Abstract: A subassembly electrical isolation connector for interconnecting adjacent tubular drill rods of a drilling system used in drilling bore holes in earth formations electrically isolates the inner connection of the drill rods. The connector comprises a housing, a mandrel, a connector for connecting the housing to a first tubular drill rod, a connector for connecting a mandrel to a second tubular drill rod and a device for interconnecting the housing and the mandrel in a manner to electrically isolate the housing from the mandrel with the housing overlapping at least a portion of the mandrel. The housing has an isolated end which is electrically isolated from the mandrel and the connector for connecting the mandrel to a second tubular drill rod. The mandrel has a conical tapered body portion which is located within the housing and the housing has a corresponding conical tapered inner surface. The conical taper for the housing and the mandrel converge inwardly away from the housing isolated end.