Figure 14.
The process starts with a dilatant pathway forming from the injection filter. Next, pathways branch and multiple pathways grow. Then pathway propagation proceeds at different rates among the branches. After that, one branch becomes unstable and stops growing, promoting growth in other branches. The dominant pathway then grows until it becomes unstable. Next, partial closure of the dominant pathway creates gas-filled isolated pathways. Continued gas injection then produces a new pathway. The closed pathway to the isolated network section subsequently reopens with continued gas injection. Finally, all pathways continue growing until a way out of the system forms and a major gas pathway develops.Conceptual model of gas flow. See text for full description