Study on fracture propagation behavior in ultra-heavy oil reservoirs based on true triaxial experiments

LIN Botao,SHI Can,ZHUANG Li,YOU Hongjuan,HUANG Yong

Table 4 Fracture propagation regularities during fracturing.

Factors Sample No. With/without propagation through the layer Fracture propagation shape Variable value Injection rate 320 mm3·s-1 2 Yes Multiple vertical fractures 960 mm3·s-1 3 Yes Macrofractures penetrate the interlayer into the reservoir and form microfractures Viscosity 1 mPa·s 2 Yes Multiple vertical fractures 150 mPa·s 4 Yes Single fracture penetrates the interlayer and linear fracture extends along the interface Perforation number 2 2 Yes Multiple vertical fractures 4 5 Yes Fractures increased in length and width; linear macrofractures were generated in the reservoir Fracture initia- tion position Interlayer 2 Yes Multiple vertical fractures Reservoir 1 - Microfractures and a dilated zone formed in the reservoir Reservoir 6 No Microfractures and a dilated zone came up in the reservoir only; but interlayers were not fractured open