Patent ID: 9389326
Filing Date: 2016-07-12
CPC Classification: G01V

Claim Text:
1. A method of imaging a volume of the earth's subsurface near a well bore, comprising: selecting a first sub-set of a microseismic data set acquired over a data acquisition time period with a plurality of sensors located at a plurality of sensor positions disposed in proximity to the well bore, said microseismic data set representing microseismic emissions originating from faults or fractures generated in the subsurface of the earth near said well bore during a hydraulic fracturing stage at a hydraulic fracturing stage location during a hydraulic fracturing stage time period, the first sub-set of said microseismic data set representing seismic energy emissions from a first set of nodes or voxels in the earth's subsurface near said well bore at the fracturing stage location; dividing said first sub-set of a microseismic data set into a plurality of time intervals and stacking the microseismic data within each time interval; voxel-value filtering the stacked microseismic data within each of said plurality of time intervals; selecting only voxels within each time interval having voxel value magnitudes greater than a selected magnitude, thereby generating a second voxel-value filtered sub-set of said microseismic data set; within each time interval selecting from said second voxel-value filtered sub-set of said microseismic data set only groups of one or more voxels having voxel-value magnitudes greater than said selected magnitude, the selected voxels in each group being contiguous with each other, with at least one selected voxel in each group encompassing or contiguous with said well bore, thereby generating a third voxel-value-filtered sub-set of said microseismic data set determined to be near the hydraulic fracturing stage location of said well bore; stacking data across time intervals in the third voxel-value-filtered sub-set of said microseismic data set to form stacked filtered voxel values in the third set of nodes or voxels to generate a fourth sub-set of said microseismic data set, and