Learn about pulse chemisorption, a technique for characterizing catalysts and measuring metal surface area. Discover how AMI’s instruments can help you.[…]
Learn how the Densi 100 True Density Analyzer is used to measure the true density of ceramic fracturing proppants. Ensure the quality of your proppants with AMI.
Fracturing proppants, also known as ceramic particles or ceramic sand, are sintered from high-quality bauxite and other raw materials. These proppants are widely used in deep-well and high-pressure oil/gas reservoir fracturing operations. During deep oil and gas well extraction, hydraulic fracturing is applied to low-permeability reservoirs under high closure pressure. This process fractures the hydrocarbon-bearing rock layers, creating channels for oil and gas flow. Proppants are injected with high-pressure fluid into fractures to prevent closure under stress, maintaining high conductivity and enhancing production. Field data demonstrates that ceramic proppants can increase well productivity and extend operational lifespan.⁽¹⁾ True density is defined as powder mass divided by the true volume of the powder, which is the powder volume excluding any internal pores, cracks, or voids. If the material is porous, like ceramic particles, the true density can differ significantly from the bulk density (pore volumes not subtracted). The true density of ceramic particles is directly related to proppant effectiveness. The particles sintered from bauxite tend to have high true densities, which allow them to resist crushing and breakage. However, some applications require lightweight proppants which resist particle settling and are typically less costly.⁽¹⁾ Therefore, accurate true density measurements are necessary to improve these technologies.
The Densi 100 True Density Analyzer from AMI measures true density by employing the gas displacement method. As demonstrated in the scientific literature, helium is recommended as the displacement gas for true density measurements due to its small molecular radius, high diffusivity, and chemical inertness.⁽²⁾ These properties allow helium to penetrate fine pores and cracks of powder materials. By measuring pressure changes in a calibrated chamber, the true volume and true density of the sample are determined. The procedure is as follows: Step 1: Empty Sample Cup Calibration ✓ Record initial pressure (P₀,empty) of sample and reference chamber, charging pressure (Pref,empty) of reference chamber, and equilibrium pressure (Peq,empty). Calculate the calibration parameter M P,empty using Equation (1): Step 2: Sample Measurement ✓ Load the sample and record P₀,sample, Peq,sample, and Pref,sample. Calculate M P,sample using Equation (2): Step 3: True Volume Calculation ✓ Determine the true volume (Vd) using Equation (3): , where VT is the chamber volume: Step 4: True Density Calculation ✓ Compute true density (DT) via Equation (4).
Figure 1: Instrument schematic of Densi100 True Density Analyzer from AMISample | True Density (g/cm³) | Relative Error (%) | Bulk Density (g/cm³) | Difference between True Density and Bulk Density |
|---|---|---|---|---|
1 | 2.8605 | 0.08 | 2.77 | 0.0905 |
2 | 2.8493 | 0.05 | 2.79 | 0.0593 |
3 | 3.0875 | 0.04 | 3.03 | 0.0575 |
4 | 3.0657 | 0.1 | 3.05 | 0.0157 |
Table 1: True density test results of fracturing proppants
The Densi100 produced reliable, precise true density measurements of ceramic proppants with low relative error values, shown in Table 1. These results were significantly higher compared to the bulk density measurement, which illustrates the difference between the two parameters.Model | Densi 100 |
Principle | Gas displacement method |
Pretreatment method | Gas purge, Flow |
Pressure | 0-150 kPa (Gauge) |
Gases | He (N₂) |
Accuracy | 0.03% |
Testing Range | 0.0001 g/cm³ to the infinity; |
Repeatability | 0.02% |
Cell Volume | Nominal：100 ml or 10 ml |
Available Inserts | 35 ml，10 ml or 3.5 ml，1 ml |
Calibration | Automatic calibration with calibration blocks |
Volume and Weight | L 15.0 in (380 mm) × W 11.0 in (280 mm) × H 11.0 in (280 mm), 22 lbs (10 kg) |
Power Requirements | 100 or 240 VAC, 50/60 Hz, maximum power 100 W |
Table 2: Instrument specifications and capabilities of the Densi100Figure 2: Densi100 True Density Analyzer from AMIThe Densi 100 True Density Analyzer delivers high precision (±0.03%) and reproducibility (±0.02%), fulfilling the rigorous requirements for absolute density testing of ceramic proppants. This method ensures reliable quality control in hydraulic fracturing applications. For more information on our true density analyzers, please contact us. You can also explore our full range of products or browse our technical library for more application notes.
(1) Liang, F.; Sayed, M.; Al-Muntasheri, G. A.; Chang, F. F.; Li, L. A comprehensive review on proppant technologies. Petroleum, 2016, 2, 26-39.(2) Nguyen, H. G. T.; Horn, J. C.; Bleakney, M.; Siderius, D. W.; Espinal, L. Understanding material characteristics through signature traits from helium pycnometry. Langmiur, 2019, 35, 2115-2122.True density is defined as the mass of a powder divided by its true volume, excluding internal pores or voids. For ceramic proppants, true density is critical because it determines the material’s resistance to crushing, breakage, and settling in hydraulic fracturing operations. Accurate true density ensures optimal proppant performance and well productivity.
Bulk density accounts for the total volume of a material, including internal pores and voids, while true density measures only the solid material itself. Ceramic proppants often have a higher true density than bulk density, which is essential for evaluating their structural integrity under high-pressure fracturing conditions.
The gas displacement method involves using an inert gas, typically helium, to penetrate the fine pores of a powder sample. By measuring pressure changes in a calibrated chamber before and after introducing the sample, the instrument calculates the true volume and density. This technique provides precise and reproducible true density measurements.
Helium is chemically inert, has a small molecular size, and high diffusivity, allowing it to access fine pores and cracks in powder materials. These properties make helium ideal for accurately measuring the true density of porous materials like ceramic proppants.
The Densi 100 uses automatic calibration, precise pressure measurement, and controlled gas flow to deliver high-precision (±0.03%) and reproducible (±0.02%) results. Its capability to measure a wide range of volumes and densities ensures reliable quality control for ceramic proppants used in hydraulic fracturing.
Learn about pulse chemisorption, a technique for characterizing catalysts and measuring metal surface area. Discover how AMI’s instruments can help you.[…]
Discover how specific surface area and pore structure affect the performance of potassium-ion batteries. Learn how AMI’s instruments can advance your battery research.[…]
Learn how differential scanning calorimetry (DSC) is used to analyze the thermal properties of lipstick. See how the AMI DSC 600 can help you develop high-quality cosmetics.[…]
Understanding TPD kinetics, surface characterization, and desorption dynamics for heterogeneous catalyst analysis.[…]