HIGH-POWER WELL LOGGING METHOD AND APPARATUS

摘要

A system and method for safely and economically providing up to 1800 watts t o downhole equipment is shown in the figure. In one embodiment, the system use s a standard multiconductor logging cable (20) which supports orthogonal signa l transmission modes on circumferentially spaced insulated conductors (1, 2, 3 , 6, 7). A high-powered power source on the surface (M1, M2. M3, M4) is couple d to the insulated conductors in the cable to drive a power signal on the lowe st impedance signal transmission mode. Safety may be enhanced by the addition o f a reliable current imbalance detector configured to shut down all power sour ce when currents in the insulated conductors do not add to zero. The system may further include multiple power sources operating on different independent signal transmission modes, and may also include multiple telemetry channels which share the power transmission modes via multiplexing.