Downhole seismic array system

This patent describes an apparatus of receiving seismic signals from an earth formation at least at one or more points in a wellbore penetrating the formation. It comprises a sonde including extensible and retractable support means thereon for supporting seismic signal receiver means, hydraulic actuator means for extending and reacting the support means, body means for supporting the actuator means and the support means and signal transmitting means for transmitting electrical signals related to seismic signals received by the receiver means; tubing means connected to the sonde for deploying the sonde in the wellbore, the tubing means including electrical conductor means disposed therein for conducting electrical signals between means on the surface of the formation and the sonde and the tubing means comprising means for conducting hydraulic fluid to the sonde for operation of the actuator means; and means for supplying hydraulic fluid from the surface of the formation through the tubing means to the sonde for operating the actuator means