Nanoseis LLC

Global Microseismic Services, Inc.

David E Diller

Barry Fish

Charles John Sicking

Ran Xuan

Disclosed herein are various embodiments of methods and systems for optimizing the analysis of the source locations of microseismic sources, comprising recording microseismic data using patches of sensors. Each patch contains multiple sensors, arranged as a grid or a line segment. This approach uses fewer sensors and can cover a larger area than previous techniques for acquiring microseismic data. The data recorded in this way can be filtered using directional filters, such that each patch may be targeted at a specific point in the subsurface. The microseismic source-scanning algorithm benefits from having data filtered to include directional signals only from pairs of patch locations and subsurface locations. This produces an improved estimate of the locations of microseismic events. The patches may be disposed about a horizontal well bore, and aligned such that directional filtering enhances data from hydraulic fracturing operations in the wellbore.

System and method for microseismic data acquisition using sensor patches

Disclosed herein are various embodiments of methods and systems for optimizing signals generated by microseismic sources, comprising recording microseismic data using patches of geophones, filtering the data to impart a directionality to the data, and performing a source scan to determine the times and locations of microseismic events. The subsurface is divided into a voxel grid that is further subdivided into subgrids. Using a filter designed for each patch-subgrid pair, only data arriving within a predetermined angle of incidence are input to the source scan, thus reducing noise, and enhancing the quality and accuracy of the identified microseismic events. The method is also applicable to data previously recorded with sensor grids or other arrays such as star arrays.

System and method for narrow beam scanning microseismic monitoring

Disclosed herein are various embodiments of methods and systems for determining the orientation and direction of first motion of a fault or fracture by optimizing an azimuthally-dependent attribute of signals generated by microseismic sources, comprising: recording microseismic data traces using a of sensors located at a plurality of sensor positions; subdividing the subsurface volume into spatial volumes corresponding to selected time intervals and comprising a plurality of voxels; for each voxel, applying a time shift to the microseismic data traces that is substantially equal to a travel time from each voxel to the corresponding sensor position, and determining for the voxel the orientation and direction of first motion of the fault or fracture corresponding to a maximum value for the voxel of at least one azimuthally-dependent attribute of the microseismic data traces.

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Greenwood Village, CO, United States of America

David E Diller