Multi-point resistivity measurement system for full-diameter long cores during fluid displacement

Area of Science:

• Petroleum Engineering
• Geophysics
• Reservoir Characterization

Background:

• Water injection is crucial for enhanced oil recovery, but it alters reservoir resistivity.
• Accurate resistivity measurements are vital for evaluating remaining oil and gas saturation.

Purpose of the Study:

• To design and validate a multi-point resistivity measurement system for core samples during fluid displacement.
• To investigate resistivity distribution and variation in reservoirs undergoing water flooding.

Main Methods:

• Developed a system with columnar and nail-shaped electrodes for multi-point resistivity measurement on full-diameter core samples.
• Employed electrical bridge metering with seven electrodes to measure resistivity across six sections of the core.
• Applied confining pressure to ensure electrode contact and simulate downhole conditions.

Main Results:

• Successfully simulated water flooding on a Tarim Oilfield sandstone sample.
• Recorded resistivity distribution and variation throughout the experiment.
• Experimental results align with rock physics principles, validating the system's reliability.

Conclusions:

• The developed experimental system reliably measures resistivity variations in water-flooded reservoirs.
• This system offers a valuable tool for assessing remaining oil and gas saturation.
• Provides a guideline for understanding reservoir behavior during enhanced oil recovery operations.