Tight
reservoirs, as an important alternative for conventional
energy resources, have been successfully exploited with the aid of
hydraulic fracturing technologies. Because of the inherent ultralow
permeability and porosity, tight oil reservoirs generally suffer from
the effects of stress sensitivity. Both hydraulic fractures with complex
geometries and a high-permeability area known as stimulated reservoir
volume (SRV) may be generated by the massive hydraulic fracturing
operations. All these bring huge challenges in transient pressure
analysis of tight reservoirs. Up till now, although many research
studies have been carried out on the transient pressure analysis of
volume-fractured horizontal wells in tight reservoirs, unfortunately,
there is still a lack of research studies that have taken stress sensitivity,
complex fracture networks, and the SRV into consideration, simultaneously.
To fill up this gap, this paper first idealizes the reservoir after
hydraulic fracturing as two radial composite regions, that is, the
unstimulated outer region and the inner SRV. The stress sensitivity
is characterized by the variable permeability depending on the pore
pressure. A linear source with consideration of the stress sensitivity
in the composite reservoir is obtained by the perturbation technique,
Laplace transformation, and the flow coupling of two regions. Second,
the complex fracture networks are discretized into segments to capture
their geometries. A semi-analytical model is finally established and
validated by the comparison with previous models. On the basis of
our model, six flow stages of volume-fractured horizontal well are
identified and special features of each regime are analyzed. The stress
sensitivity has a great impact on the later stage of production. The
mobility ratio and the SRV radius mainly affect SRV pseudo-steady-state
flow period and interporosity flow period in the outer region. Fracture
number mainly affects the linear flow in the SRV. Fracture geometries
mainly affect linear flow and interporosity flow in the SRV. This
study has some significance for well test interpretation and production
performance analysis of tight reservoirs.