A continuum damage model for predicting the damage initiation and development in three-dimensional (3D) woven composites is proposed, in which the fiber fracture, inter-fiber fracture and matrix fracture are considered in the level of the fiber yarn and the matrix.
Moreover, much fiber and matrix fracture was observed during dynamic loading progress.
In oil-wet FR, steam enters fractures and then heats the matrix block, however, oil cannot move out from matrix until fractures are filled with steam, therefore oil drains from the matrix to fracture due to density difference between oil in matrix and steam in the fracture.
The permeability values in the matrix and fractures are changed to 0.005 and 50 md, respectively, to guarantee apparent dual-porosity behavior.
Both rock matrix and fractures are modeled by three-dimensional equivalent pipe networks to simulate the H-T-C coupling process in fractured carbonate rock.
Then, basis functions for matrix and fractures are constructed by restricted smoothing, which gives a flexible and robust treatment of complex geometrical features and heterogeneous coefficients.
Model studies show that gravity drainage occurs in simulations using the dual permeability conceptual model, but is absent in the effective-continuum model, where matrix and fractures are required to be in thermodynamic equilibrium at all times.
Interfacial debonding, fiber fracture and matrix cracking are considered to simulate the hysteresis loops.
coalbed methane, shale gas/oil, ultra-low permeability oil reservoir) around the world, the subject of stress-dependent permeability is also of great interest because the ultra-tight matrix and natural/generated fractures are more susceptible to stress-state changes.
Figure 5a depicts a schematic of a matrix-fracture system in which spontaneous imbibition between matrix and fractures was simulated by an Amott cell (Fig. 5b).
