1. What is Volume Percent of Porosity?

Volume Percent of Porosity gives the volume percentage of a porous material that consists of void spaces. It represents the total pore space available for fluid storage within a rock or soil formation.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( \eta_v \) — Volume Percent of Porosity (%)
• \( \%S_y \) — Specific Yield Percentage (%)
• \( \%S_r \) — Specific Retention Percentage (%)

Explanation: Specific Yield Percentage tells how much water is available for consumptive use, while Specific Retention Percentage tells how much water remains in the rock after it is drained by gravity. Their sum gives the total porosity.

3. Importance of Porosity Calculation

Details: Accurate porosity calculation is crucial for groundwater studies, petroleum engineering, soil mechanics, and environmental assessments. It helps determine the storage capacity of aquifers and reservoir rocks.

4. Using the Calculator

Tips: Enter Specific Yield Percentage and Specific Retention Percentage as positive values. Both values must be valid percentages (≥0).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between Specific Yield and Specific Retention?
A: Specific Yield is the water that drains by gravity, while Specific Retention is the water retained against gravity by molecular attraction and surface tension.

Q2: What are typical porosity values for common materials?
A: Sand: 25-50%, Clay: 40-70%, Sandstone: 5-30%, Limestone: 5-20%, Granite: 0.5-1.5%

Q3: Can porosity exceed 100%?
A: No, porosity is always between 0% and 100% as it represents the fraction of void space in a material.

Q4: How is porosity measured in laboratory settings?
A: Common methods include mercury intrusion porosimetry, gas expansion methods, and fluid saturation techniques.

Q5: Why is porosity important in groundwater studies?
A: Porosity determines the water storage capacity of aquifers and affects the movement and availability of groundwater resources.