Oil well logging device having plural well fluid parameter measuring devices and a single conductor for accommodating both measurement and power signals

Claim 1

An instrumentation array for use in oil well logging, by measuring the parameters of the fluid in the well, comprising: a cylindrical housing; a plurality of circuit segments adapted for axial receipt within said housing, each circuit segment including feedthrough connections to transfer electrical signals between adjacent ones thereof; a plurality of sensing means interposed between selected ones of said segments, each sensing means being adapted to respond to a selected physical parameter of said fluid by producing a continuous analog signal indicative in amplitude of the amplitude of said parameter; an associated voltage controlled oscillator connected and disposed proximate each said sensing means for producing electrical pulses at a pulse rate corresponding to the amplitude of said analog signal from said sensing means; an associated voltage regulator connected to each said voltage controlled oscillator for applying a reference signal thereto; recording means disposed above said well bore producing a record indicative of said pulse rate; power supply means disposed above said well bore for producing a D.C. electrical signal; and cable means including a single conductive element connected to said recording and power supply means and across said feedthrough connections to each said sensing means for conveying said electrical pulses to said recording means and said D.C. electrical signal to each said voltage regulators in superposed relationship thereacross.