Pressure Transient Behavior of Horizontal Well with Time-Dependent Fracture Conductivity in Tight Oil Reservoirs

Abstract

This work presents a discussion on the pressure transient response of multistage fractured horizontal well in tight oil reservoirs. Based on Green's function, a semianalytical model is put forward to obtain the behavior. Our proposed model accounts for fluid flow in four contiguous regions of the tight formation by using pressure continuity and mass conservation. The time-dependent conductivity of hydraulic fractures, which is ignored in previous models but highlighted by recent experiments, is also taken into account in our proposed model. We also include the effect of pressure drop along a horizontal wellbore. We substantiate the validity of our model and analyze the different flow regimes, as well as the effects of initial conductivity, fracture distribution, and geometry on the pressure transient behavior. Our results suggest that the decrease of fracture conductivity has a tremendous effect on the well performance. Finally, we compare our model results with the field data from a multistage fractured horizontal well in Jimsar sag, Xinjiang oilfield, and a good agreement is obtained.

Transient Pressure Performance Analysis of Hydraulically Fractured Horizontal Well in Tight Oil Reservoir

“…In this paper, we take a fractured horizontal well in tight oil reservoirs as an example [18,27,28,[37][38][39]: the reservoir has a length of 3000 m, a width of 2000 m, a thickness of 10 m, an initial formation pressure of 30 MPa, an initial formation permeability of 2 mD, a permeability modulus of 0.02 MPa −1 , three fractures with a fracture half-length of 30 m, fracture spacing of 200 m, fracture conductivities (FCD) of 30 cm•µm 2 , a formation volume factor of 1.2, a fluid viscosity of 2 mPa•s, a total compressibility of 4 × 10 −4 MPa −1 , a TPG of 0.02 MPa/m, a productivity of 50 m 3 /d, a wellbore storage coefficient of 0.1 m 3 /MPa, and its outer boundary is closed.…”

“…To assess the precision of the aforementioned transient flow model, we simplify the fractured horizontal well into a fractured vertical configuration [37,40]. A reservoir radius of 500 m, a fracture half-length of 100 m, and a daily production rate of 20 cubic meters have been given, and the effects of TPG and stress sensitivity are disregarded.…”

Optimization of reasonable production pressure drop of multi-stage fractured horizontal wells in tight oil reservoirs

“…Furthermore, during the oil production, the primary fractures may be gradually closed, while the permeability of the primary fracture decreases and the fracture width is reduced. Therefore, the fracture conductivity is declining, thereby affecting the productivity of horizontal wells (Feng et al 2017).…”

Green’s function-based type curves for multi-fractured horizontal gas wells in unconventional reservoirs

“…GFM is recognized by its systematic protocol, and the availability of a vast number of tabulated GF solutions for a variety of differential operators and domain geometries favors its implementation for a variety of physical processes [38]. While GFM has been explored in different reservoir engineering problems in the past, its application has been limited to slightlycompressible fluid-based formulation [39,40,41,42,43,44,45,46].…”