Intrafracture flow processes

Thus, OUT analysis of water-dripping intervals reveals that different time-scales of water dripping are not related to changes in boundary conditions, because the tests were conducted at a constant water level in the water-siq>ply gallery, but to variations in intrafracture flow processes and capillary barrier effects. 

Laboratory Experiments to Study Intrafracture Flow Processes... 

Aldiough direct measurements of variables characterizing (he individual flow and chemical transport processes under field condidons are not technically feasible, their cumulative effect can be characterized by the phase-space analysis of time-series data for the infiltration and outflow rates, capillary pressure, and dripping-water frequency. The tune-series of low-frequency fluctuadons (assumed to represent intrafracture flow) are described by three-dimensional attractors similar to those fi m die sohidon of the Kuramoto-Sivashinsky equadon. These attractoia demonstrate die stretching and folding of fluid elements, followed by diffusion. 

Nonlinear (fynamic processes such as episodic and preferential flow, hinneling and divergence of flow pa, transient flow behavior, nonlinearity, film flow along fracture suites, intrafracture water dripping, entrapped air, fracture-matrix interaction, and pore-throat effects. 

Laboratory and field experiments show die presence and interplay of such processes as intrafracture film flow along fracture surfaces, coalescence and divergence of multiple flow paths along fracture surteces, and intrafracture water dripping. The nonlinear dynamics of flow and transport processes in unsaturated fractured porous media arise from die dynamic feedback and conpetition between various nonlinear physical processes along widi the complex geometry of flow paths. The apparent randomness of (he flow field does not prohibit the system s determinism and is, in fact, described by deterministic chaotic models using deterministic differential or difference-differential equations. 

---