ApplicationNo. 06/866896 filed on 05/27/1986
US Classes:340/854.9, Cable or wire (e.g., conductor as support, etc.)166/66, Indicating340/855.3, Multiplexed signals340/855.9, Specified alternating current (A.C.) circuit feature367/81WELLBORE TELEMETERING
ExaminersPrimary: Steinberger, Brian S.
Attorney, Agent or Firm
International ClassE21B 47/12 (20060101)
AbstractAn apparatus for measuring one or more parameters of the subsurface environment, and telemetering one or more parameters of the subsurface environment to the surface. Apparatus at the surface includes a source of intermediate frequency and voltage, electrical energy for transmission down one or more conductors of a power cable or separate instrument wire to a downhole instrument package. This intermediate frequency voltage is converted to a power supply voltage for generating a high frequency FM signal, in accordance with the magnitude of one or more parameters of the environment. This frequency modulated signal is sent to the surface over the conductors of the power cable and ground. At the surface the signal is demodulated to produce a signal indicative of the transmitted parameter.