US Patent 7668041 Apparatus and methods for acquiring seismic data while tripping

A system for acquiring logging data comprises a controller for causing the generation of a signal in a formation surrounding a wellbore. The controller has a first clock for time-stamping a record of the generated signal. A receiver is deployed in the wellbore and is adapted for detecting the signal. A second clock comprises a double-oven surrounding a crystal oscillator. A controller is operatively coupled to the double-oven to maintain the crystal oscillator temperature substantially at the crystal oscillator turnover temperature. The second clock is synchronized with the first clock before deployment in the wellbore, and the receiver references the second clock in order to record a time-stamp associated with the detected signal.