Compensated ensemble crystal oscillator for use in a well borehole system

A method for measuring time from within a borehole, the method comprising;

• (a) providing an ensemble of quad compensated clocks, each said quad compensated clock comprising four oscillator crystals;
• (b) configuring said oscillator crystals in each said quad compensated clock to a sensitivity vector of each said oscillator crystal to form a quad compensated resonator;
• (c) combining outputs of said oscillator crystals in said quad compensated resonator to form a quad compensated clock output;
• (d) using a compensation algorithm resident in a processor cooperating with said quad compensated resonator, combining each said quad compensated clock output thereby correcting said quad compensated clock output for changes in response properties of said crystals;
• and
• (e) selecting said configuration and said combination of outputs of said oscillator crystals to reduce effects of acceleration upon said quad compensated clock output.

A method for measuring time from within a borehole, the method comprising:

• (a) providing an ensemble of quad compensated clocks, each said quad compensated clock comprising four oscillator crystals;
• (b) configuring said oscillator crystals in each said quad compensated clock to a sensitivity vector of each said oscillator crystal to form a quad compensated resonator;
• (c) combining outputs of said oscillator crystals in said quad compensated resonator to form a quad compensated clock output;
• and
• (d) selecting said configuration and said combination of outputs of said oscillator crystals to reduce effects of acceleration upon said quad compensated clock output:
• wherein,
• (e) said ensemble comprises four said quad compensated clocks;
• and
• (f) each said quad compensated clock output from each said quad compensated clock are combined to yield an a quad compensated ensemble crystal oscillator clock output exhibiting less frequency drift as a function of time than any one said quad compensated clock in said ensemble.

A method for measuring time from within a borehole using a quad compensated clock, said method comprising:

• (a) forming a quad compensated resonator by
• (i) providing four oscillator crystals,
• (ii) electrically connecting said four oscillator crystals in series with their acceleration sensitivity vectors aligned, nominally one per quadrant, in a common plane, and
• (iii) configuring said crystal oscillators in pairs so that maximum acceleration sensitivity vectors of oscillators comprising said pairs are in opposite directions;
• (b) providing oscillator circuitry cooperating with said quad compensated resonator;
• (c) providing said measure of time by combining outputs of said oscillator crystals in said quad compensated resonator and inputting to said oscillator circuitry to form a quad compensated clock output with reduced sensitivity to acceleration;
• and
• (d) during a predetermined time interval, combining said quad compensated clock output with output from a quad compensated temperature sensor using a compensation algorithm resident in a processor cooperating with said clock to correct said quad compensated clock output for variations in crystal properties.