Integrated Subsurface Evaluation

Principles of Hydrophysical Logging

Top of Well or Interval

Schematic of well with multiple producing zones. During pumping/non-pumping conditions, each zone is characterized by two parameters: volumetric rate of inflow/outflow, qi, and interval specific concentration, Ci, of the constituent of interest. These constituents range from total dissolved solids (TDS), pH, and hardness (calcium, magnesium, iron) to aqueous phase VOCs, pesticides and radionuclides.

Flow

Flow schematic with the pump set above the upper most producing intervals(e.g. fractures): a step change increase in flow will occur at each producing interval. As fluid moves from the bottommost interval toward the pump, the flow rate will increase in a step-like function until the point above X3 where total flow is observed.

Interval Specific Fluid Electrical Conductivity

In addition to quantification of flow, HpL evaluates interval specific fluid electrical conductivity (~ TDS).

Fluid Electrical Conductivity

The integrated relationship between flow and FEC results in a unique time series of electrical conductivity profiles during pumping after the borehole is flushed with deionized water.

Interval Specific Aqueous Contamination Concentration

As HpL can identity water bearing zones during pumping, a down hole discrete point fluid sampler can be used during flowing conditions to obtain samples above each interval. The observed concentrations generated by this hydrochemical analysis and the interval specific flow rates are used to calculate “actual” (pore water) concentrations of any aqueous phase contaminant.