4D-stress evolution of tight sandstone reservoir during horizontal wells injection and production: A case study of Yuan 284 block, Ordos Basin, NW China

ZHU Haiyan,SONG Yujia,LEI Zhengdong,TANG Xuanhe

Table 1 Model parameters of the reservoir in the study area

Parameter Value Parameter Value Initial reservoir pressure coefficient 0.75 Compressibility coefficient of oil 1.383 × 10-3 MPa-1 Initial reservoir temperature 69.7 °C Compressibility coefficient of water 1.000 × 10-3 MPa-1 Initial porosity 8%-15% Oil viscosity 9.70 mPa·s Initial oil saturation 50% Water viscosity 1.03 mPa·s Young’s modulus 16.9-34.7 GPa Oil density at standard condition 720 kg/m3 Poisson’s ratio 0.247-0.367 Water density at standard condition 1 000 kg/m3 Oil saturation pressure 9.86 MPa Oil volume factor 1.34 Biot coefficient 0.78 Water volume factor 1.00 Initial permeability (0.05-1.50) × 10-3 μm2 Initial maximum horizontal principal stress gradient 1.96-2.04 MPa/100 m Initial vertical stress gradient 2.48-2.57 MPa/100 m Initial minimum horizontal principal stress gradient 1.65-1.72 MPa/100 m