Fracture Flow Characterization with Low-Noise Spontaneous Potential Logging

Area of Science:

• Geophysics
• Hydrogeology
• Environmental Science

Background:

• Geophysical well logging is vital for characterizing fractures in crystalline terrains.
• Existing methods using physical properties and borehole imaging aid in monitoring pumping tests.
• Identifying fractures contributing to groundwater flow is key for assessing aquifer properties.

Purpose of the Study:

• To present a novel procedure for identifying fractures that contribute to groundwater flow.
• To utilize spontaneous potential (SP) measurements for fracture characterization.
• To determine hydraulic conductivity and transmissivity by analyzing electrokinetic processes.

Main Methods:

• Application of geophysical well logging techniques.
• Monitoring spontaneous potential measurements during borehole water head changes (lowering and recovery).
• Interpretation of electrokinetic data using a tabular gap flow model to determine driving water head differences.

Main Results:

• Preliminary results demonstrate the effectiveness of the spontaneous potential method in identifying flowing fractures.
• The electrokinetic model successfully interpreted measured data to estimate water head differences.
• The procedure shows promise for characterizing hydraulic properties in crystalline rock formations.

Conclusions:

• Spontaneous potential measurements offer a viable method for detecting fractures involved in groundwater flow.
• This technique enhances the understanding of hydrogeological properties in crystalline terrains.
• Further application at the test site will refine the procedure for practical hydrogeological assessments.