Gas-Driven Fracturing of Saturated Granular Media
James M. Campbell, Deren Ozturk, and Bjørnar Sandnes
Phys. Rev. Applied 8, 064029 – Published 29 December 2017
Gas-driven fracturing underlies both natural and industrial processes, such as volcanic degassing, methane venting, stimulated hydrocarbon extraction, and treatment of contaminated soil. The authors show how in such a complex system the capillary, frictional, and viscous interactions together produce a range of fracture patterns, with cracks separated by a characteristic length that varies based on the conditions. Discovering how material properties and injection rate affect these patterns helps to establish a physics framework for optimizing permeability and assessing risk in gas-driven fracturing of hydrocarbon reservoirs and remediation of polluted soil.
Guillaume Dumazer (UiO) presented at Powders & Grains 2017.
Download paper: “Self-Structuring of Granular material under Capillary Bulldozing“. Guillaume Dumazer, Bjørnar Sandnes, Monem Ayaz, Knut Jørgen Måløy and Eirik Flekkøy. EPJ Web Conf. Vol. 140, 2017.
A repeating pattern of granular plugs emerges when a tube filled with water and grains is slowly drained. The moving air-water meniscus bulldozes the grains ahead, and friction eventually causes the grains to jam, forcing the air to penetrate through the accumulated material. Once through to the other side, the air starts to pile up another plug, and the process repeats until the whole tube is clogged full of granular plugs separated by empty gaps.
Dumazer et al., Frictional Fluid Dynamics and Plug Formation in Multiphase Millifluidic Flow. Phys. Rev. Lett. 117, 028002 – Published 7 July 2016. Dumazer_PRL028002