Differential phase semblance apparatus, systems, and methods

A system, comprising:

• a down hole tool;
• a set of receivers attached to the downhole tool, the set of receivers arranged as azimuthally separated receiver arrays, each receiver array having front and back receivers to form sum and difference channels;
• logic attached to the downhole tool to record raw signal data corresponding to energy waves propagated through a geological formation before being received by the set of receivers;
• and
• a signal processor to transform the raw signal data into signal data, to shift the signal data associated with the set of receivers in time or phase with respect to the signal data associated with a receiver reference point, to multiply the shifted data by a complex conjugate of the signal data associated with the receiver reference point to provide differential phase values associated with the set of receivers, and to sum and average the differential phase values over the set of receivers at each time of selected times for a given slowness or over the set of receivers at each frequency of selected frequencies for a given slowness to provide differential phase semblance values;
• and
• a device operable with the signal processor to publish a slowness time semblance image or a slowness frequency semblance image based on the differential phase semblance values, the device being one of a storage medium, a hardcopy printout device, or a display.

A processor-implemented method to execute on one or more processors that perform the method, comprising:

• receiving, by a set of receivers arranged as azimuthally separated receiver arrays, each receiver array having front and back receivers to form sum and difference channels, received energy waves, the received energy waves resulting from generated energy waves propagating through a geological formation;
• shifting signal data associated with the set of receivers, in time or phase with respect to signal data associated with a receiver reference point;
• multiplying the shifted data by a complex conjugate of the signal data associated with the receiver reference point to provide differential phase values associated with the set of receivers;
• summing and averaging the differential phase values over the set of receivers at each time of selected times for a given slowness or over the set of receivers at each frequency of selected frequencies for a given slowness to provide differential phase semblance values;
• and
• publishing a slowness time semblance image or a slowness frequency semblance image, the differential phase semblance values, to one of a storage medium, a hardcopy printout, or a display.

An article including a non-transitory, machine-accessible medium having instructions stored therein, wherein the instructions, when executed, result in a machine performing:

• receiving, by a set of receivers arranged as azimuthally separated receiver arrays, each receiver array having front and back receivers to form sum and difference channels, received energy waves, the received energy waves resulting from generated energy waves propagating through a geological formation;
• shifting signal data associated with the set of receivers, in time or phase with respect to signal data associated with a receiver reference point;
• multiplying the shifted data by a complex conjugate of the signal data associated with the receiver reference point to provide differential phase values associated with the set of receivers;
• summing and averaging the differential phase values over the set of receivers at each time of selected times for a given slowness or over the set of receivers at each frequency of selected frequencies for a given slowness to provide differential phase semblance values;
• and
• publishing a slowness time semblance image or a slowness frequency semblance image based on the differential phase semblance values to one of a storage medium, a hardcopy printout;
• or a display.