FRACTURE AND AMENDMENT MAPPING USING TILTMETER GEOPHYSICS

Knowing the configuration and geometry of individual fractures initiated and propagated in subsoils is extremely useful for assessing the subsequent performance of remediation technologies at fracture-enhanced sites. This is especially true in cases where the soil fracturing process includes delivering chemical or biological amendments for expediting in situ remediation.

Fractures placed in the subsurface can be mapped remotely using surface mounted tiltmeters. Tiltmeters are highly sensitive instruments (to microradian resolution) used in the hydraulic fracturing industry to measure the minute ground surface deformations created during the fracturing process. The direction and magnitude of micro ground surface deformation or “tilt” measured by tiltmeters is used to determine the shape, thickness, extent and orientation of fractures and amendment distribution in the subsurface. This information is useful in confirming the extent and areal coverage of fractures placed in the subsurface, as few fractures ever propagate in a perfectly radial or horizontal manner. Tiltmeter geophysics is superior to other methods for fracture mapping because it does not suffer from signal attenuation or other masking effects of “top-down” looking geophysical methods.

Individual fractures and the entire fracture network are depicted as animations that can be viewed from any perspective using advanced computer graphics software.