The influence of the fractal particle size distribution on the mobility of dry granular materials

Based on the fractal particle size distribution, a fragmentation theory for quasi-brittle materials is herein developed. The results are three simple and powerful universal laws for the multiscale energy dissipation under impact and explosion fragmentation for one, two, and three-dimensional bodies, respectively. The three-dimensional law unifies the most important and well-known fragmentation theories. As an example, it has been applied to the prediction of the devastated area due to asteroid impacts on earth as a function of the energy released in the collision.

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The Research into Determination of the Particle-Size Distribution of Granular Materials by Digital Image Analysis

Springer Proceedings in Energy - Renewable Energy Sources: Engineering, Technology, Innovation ◽

10.1007/978-3-319-72371-6_61 ◽

2018 ◽

pp. 623-630 ◽

Cited By ~ 1

Author(s):

Artur Wójcik ◽

Wioletta Przybyła ◽

Sławomir Francik ◽

Adrian Knapczyk

Keyword(s):

Particle Size ◽

Image Analysis ◽

Particle Size Distribution ◽

Size Distribution ◽

Granular Materials ◽

Digital Image ◽

Digital Image Analysis

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Screening of Lost Circulation Materials for Geothermal Applications: Experimental Study at High Temperature

Journal of Energy Resources Technology ◽

10.1115/1.4053071 ◽

2021 ◽

pp. 1-16

Author(s):

Cesar Vivas ◽

Saeed Salehi

Keyword(s):

Particle Size ◽

High Temperature ◽

Thermal Degradation ◽

Particle Size Distribution ◽

Size Distribution ◽

Granular Materials ◽

Lost Circulation ◽

Key Factor ◽

Sealing Pressure ◽

Lost Circulation Materials

Abstract This study presents a laboratory experimental research to determine the characteristics of lost circulation materials (LCM) capable of addressing thermal degradation, providing bridging, and sealing in geothermal conditions. Eleven different materials were tested; Walnut Fine, Walnut Medium, Sawdust, Altavert, Graphite Blend, Bentonite Chips, Micronized Cellulose (MICRO-C), Magma Fiber Fine, diatomaceous earth/amorphous silica powder (DEASP), Cotton Seed Hulls, and a Calcium Carbonate Blend. The filtration and sealing pressure of the LCMs were measured with HPHT equipment up to 149°C (300°F). Besides, the particle size distribution (PSD) of fine granular materials was measured. The results show that the performance of some LCM materials commonly used in geothermal operations is affected by high temperature. Characteristics such as shape and size made some materials more prone to thermal degradation. Also, it was found that the PSD of LCMs is a key factor in the effectiveness of bridging and sealing fractures. The results suggest that granular materials with a wide particle size distribution PSD are suitable for geothermal applications.

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