At a glance: Hydraulic Profiling Tool (HPT)
- The Hydraulic Profiling Tool is a logging tool that measures the pressure required to inject a flow of water into the soil and the electrical conductivity of the formation.
- The injection pressure log is an excellent indicator of formation permeability revealing the depth of confining layers.
- The HPT can be used to measure hydro-static pressure under the zero flow conditions for accurate water table depths.
- A graph of hydraulic conductivity estimated from an HPT log is readily transferable to groundwater flow models.
- The HPT is also useful for the detection of brines or other high electrical conductivity fluids in soil. These brines may originate from oilfield production or storage activities. Other high ionic fluids amenable to this technique include road salts and remediation fluids.
- HPT probes are robust, driveable under all Geoprobe
HPT logs are also used to develop lithologic cross sections of the subsurface. This is a powerful application of HPT, allowing the site investigator to trace aquifer materials or confining zones across a site. It also allows the comparison of lithology between locations based on apparent permeability.