A Cost-effective System for Hydraulic Conductivity Measurement and Fracture Detection in Boreholes

Period of Performance: 09/28/1995 - 09/27/1997

$579K

Phase 2 SBIR

Recipient Firm

NEW England Research, Inc.
331 Olcott Drive, Suite L1
White River Junction, VT 05001
Principal Investigator

Abstract

A rapid and inexpensive technique for permeability measurement and fracture detection in boreholes would contribute to a significant advance in our ability to deal with economic, societal, and technical issues associated with subsurface fluid movements; these issues include resource detection and recovery, pollution monitoring and remediation, aquifer evaluation and exploitation, and geotechnical concerns. We will implement, test, and operate a simple two-receiver two-frequency-range sonic logging tool that will support permeability estimation. The estimate will be based on Stoneley wave amplitude decay and uses existing, well-studied processing technology. We will replace the shear velocity log with one derived from Stoneley wave dispersion; we will replace the density and porosity logs normally used in our processing with estimates based on correlations with elastic velocities. The final tool will carry sonic, caliper, and gamma ray sensors. As part of the evaluation process we will operate a mini-packer tool modified to perform pressure measurements at very short times. These data will provide fracture and permeability characterization information and different scales than the sonic tool, and will provide valuable information on tying the sonic permeability estimates to flow-derived estimates at longenr periods. This technology will be attractive to both wireline service providers (to whom we propose to transfer the processing and interpretation technology) and to end users concerned with subsurface fluid transport. When widely available, it will greatly reduce the uncertainty in predicting flow patterns.