The
stimulated reservoir volume fracturing development in tight
oil reservoirs is characterized by multiscale flow of the reservoir
matrix, fracture network, and hydraulic fracture. Therefore, the flow
field structure is extremely complex. Multiscale flow characteristics
have been revealed through the systematical experiments including
the threshold pressure gradient and the stress sensitivity. Based
on the theory of elliptical flow, a comprehensive and practical mathematical
model of multiregion coupling flow is established to characterize
the multiscale flow, and the pressure distribution equation is derived.
The calculation method of moving boundary is established to simulate
the dynamic supply boundary and the dynamic pressure distribution
by using the steady-state sequential replacement method. The characteristics
of multiscale flow, multistage development state, and stress sensitivity
are considered, especially the different stress sensitivity characteristics
in different regions. Finally, the pressure propagation in tight reservoirs
is clarified and the influence of matrix permeability, stress sensitivity
characteristics, and drawdown pressure on the distance at the dynamic
supply boundary are revealed. The research results provide theoretical
basis for the development effect evaluation.