HIGH RESOLUTION FLOWMETER LOGGING PART 1: FLOWMETER TECHNIQUES AND EQUIPMENT DEVELOPMENT

High-resolution flow logging has the potential to significantly improve geophysical interpretations in ground-water studies associated with site characterization. Borehole flowmetering is a technique included in the standard suite of geophysical well logs that can provide a direct measurement of the hydraulic properties of sediments and fractured rocks adjacent to boreholes. For many years the resolution of available borehole flowmeters severely limited their application in aquifer studies. New generation, potentially more accurate, borehole flowmeters described in this presentation enhance site characterization where sub-surface fluid flow in important. Principles behind these techniques are based on laser and acoustic Doppler, electromagnetic, heat-pulse, fluid conductivity profiling, photometric & colorimetric dye, and acoustic scattering measurements.

This presentation reviews various borehole flow measurement techniques along with recent innovations as described in literature. Estimates of resolution limits, probe details and special requirements associated with each technique are compared. Advantages and pitfalls are described.