Abstract: An electromagnetic communication system for a wellbore drilling instrument includes a first antenna disposed in a pressure tight compartment in a wall of a drill collar or a pressure tight sonde and a second antenna disposed in a pressure tight sonde disposed in an interior passage in the drill collar or in a pressure tight compartment in a wall of the drill collar. A wall thickness of the drill collar and/or a wall thickness of the sonde, an electrically conductive material used for the drill collar and the sonde and a frequency of electromagnetic signals applied to at least one of the antennas are chosen to enable electromagnetic communication between the first antenna and the second antenna disposed.

Abstract: Methods and apparatus for communicating between a MWD or LWD logging tool and a surface processor, such as a PC, using a high speed transmission control protocol-internet protocol (TCP-IP) based connection link. Logging tool sensor response is stored in memory within the tool while logging. The link is removably attached to a data port in the tool when the tool is subsequently removed from the borehole. Stored sensor response information is transferred very rapidly from tool memory as TCP-IP data packets. Transmission is two-way thereby allowing commands to be transmitted from the PC to the tool for control of the tool and the data acquisition function of the tool. The two-way data transmission function can be performed at one or more PC's remote from a drilling rig using a commercially available TCP-IP hub and the internet.