Gas-driven fracturing

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.

Campbell_2017_PRAppl_preprint

Granular plugs

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