Abstract: A downlink system that includes at least one mud pump for pumping drilling fluid from a drilling fluid storage tank to a drilling system, a standpipe in fluid communication with the mud pump and in fluid communication with the drilling system, and a return line in fluid communication with the drilling system for returning the drilling fluid to the drilling fluid storage tank is provided. A drilling fluid modulator may be in fluid communication with at least one of the group consisting of the standpipe and the return line.

Abstract: Body (22) for measuring the resistivity of a formation (9) surrounding a well (10) equipped with a lining (11), comprising: a body (23) of a probe (22), a set of three primary voltage measurement electrodes (ea, eb, ec), an upper electrode (ea) and a lower electrode (ec) and a central electrode (eb), two electrodes (In1, In2), an upper current injection electrode (In1) and a lower current injection electrode (In2) arranged on each side of the set of primary electrodes, characterized in that it also comprises, two secondary voltage measurement electrodes (24, 26) arranged on each side of the set of primary electrodes (ea, eb, ec), and between the two current injection electrodes (In1, In2), the spacing between a secondary electrode (24, 26) and the closest primary end electrode (ea, ec) being more than 1.5 times the spacing between the primary electrodes (ea, eb, ec).

Abstract: A downlink system that includes at least one mud pump for pumping drilling fluid from a drilling fluid storage tank to a drilling system, a standpipe in fluid communication with the mud pump and in fluid communication with the drilling system, and a return line in fluid communication with the drilling system for returning the drilling fluid to the drilling fluid storage tank is provided. A drilling fluid modulator may be in fluid communication with at least one of the group consisting of the standpipe and the return line.