Research and Application of Nano-flooding Synergistic Fracturing Technology in Tight Conglomerate Reservoir Horizontal Wells in Mahu

Deployment of infill horizontal wells is an effective way to further tap the remaining reserves between potential wells and enhance oil recovery. However, compared with the initial volume fracturing of horizontal wells, the fracturing impact during infill well fracturing seriously affects the production of old wells and the effect of infill well reconstruction. However, the fracturing impact can be effectively avoided and the balanced expansion of infill well fractures can be achieved through the injection of liquid energy into old wells (parent wells). Taking the deployment area of infill well in well block Ma 131 of Mahu tight conglomerate reservoir in Xinjiang as an example, through reservoir geostress field simulation, explore the effect of water injection energy enhancement on reservoir geostress field and pore pressure field, and then take particle size distribution, reducing oil-water interfacial tension and static permeability displacement as performance evaluation indicators, select nano-surfactants for energy enhancement of old wells, and finally based on numerical simulation and indoor evaluation results, Optimize and design the nano-flooding synergistic fracturing scheme for 3 old wells and 2 infill wells. The simulation shows that the in-situ stress field and pore pressure field can be effectively reconstructed by injecting water of 0.75 –1 times deficit volume in the old well; The laboratory experiment shows that the average particle size of G-2 nano-surfactant is 73.6 nm. When the mass concentration is higher than 0.2%, the oil-water interfacial tension can be reduced to 10−2mN/m, and the static imbibition flooding efficiency of 0.2% concentration can reach 28.35%; The field application results show that the average daily oil production of three old wells is 93% higher than that before the energy increase, and the average daily oil production of two infill wells after fracturing is more than 20t, with significant effect. The relevant research can provide technical reference for improving the development effect and greatly improving the recovery factor of Mahu tight conglomerate and similar reservoirs.