Abstract:
In order to clarify the influence of different factors on fracturing energization effect, the whole process of fracturing fluid including injection, well soaking and production in tight oil reservoirs was simulated. The natural cores from the tight oil reservoirs in the periphery of Daqing Oilfield were selected for experimental research. By monitoring the recovery degree, pore pressure and water content, the influence of factors, such as core permeability, wettability, fracture numbers, injection volume, soaking period, and shale content, on dynamic response characteristics of fracturing energization in tight oil reservoirs were analyzed. The results show that the fracturing energization technology can effectively improve the recovery rate in tight oil reservoirs, and that the better the physical properties of the reservoir and the stronger the water wettability, the better the fracturing energization effect. The recovery degree of the core with a permeability of 1.68×10
−3 μm
2 is 10.8% higher than that of the core with a permeability of 0.39×10
−3 μm
2, and the recovery degree of the core with a strong hydrophilia is 2.86% higher than that of the core with a weak hydrophilia. Furthermore, many other measures such as increasing the injection amount of fracturing fluid, increasing the number of fractures, optimizing the soaking period, and adding anti-swelling agent can all can significantly improve the recovery rate in tight oil reservoirs, which may provide technical references for oilfields.