Patent attributes
A method for taking seismic measurements that includes a downhole sensor positionable within a tool string located within the bore of a well, the tool string having a network which effects communication with a downhole sensor. The downhole sensor includes a downhole clock that may be placed in communication over the network with the top-hole clock for synchronization. A seismic source is positioned within a transmitting distance of the downhole sensor and activated at a time when the network is disconnected. The downhole sensor records signals from the seismic source at along with a downhole timestamp from the downhole clock. When the network is reconnected, the downhole clock and the top-hole clock are re-synchronized and any downhole clock drift is calculated. The recorded downhole timestamp may then be adjusted to reflect what it would have been if the downhole clock had been synchronized with the top-hole clock.
