Abstract: A signal repeater, a system utilizing one or more signal repeaters, and a method for detecting a transient disturbance in the surface charge on drill pipe, which system, apparatus and method are collectively used to transfer data from deep-well and high-conductivity formation subterranean environments to a point nearer to the surface. The signal repeater comprises a housing that is securably mountable to the interior of a pipe-string disposed in a wellbore, which repeater receives and stores electrical signals for resending at an appropriate time.

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: 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: 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.