硼交联氮气泡沫压裂液两相流流变特性实验研究

Experimental Research on the Rheological Characteristics of Two Phase Borate-Crosslinked N_2 Foam Fracturing Fluid

利用高参数泡沫压裂液实验回路研究了模拟实际压裂条件下N2硼交联泡沫压裂液的流变特性,得到了模拟实际压裂条件下N2泡沫压裂液流变参数的计算关联式,从而为低渗低压油气藏N2泡沫压裂技术的有效实施提供了实验依据。研究表明:在实际施工条件下,N2泡沫压裂液具有剪切稀化性质,可用幂律模型来描述;其有效粘度随温度的增高而减小;随压力、泡沫质量的增大而增大;相对而言,温度和泡沫质量对流变参数的影响比压力的影响要明显,在实验范围内,温度和泡沫质量对流变参数的影响均呈指数规律变化。

A detailed study has been done on experimental investigation of the friction factor and rheological characteristics with N_2-non-Newtonian liquid (N_2 foam fracturing fluid) system on the newly constructed large scale flow loop. The experiments were performed in the conditions of 15~30 MPa, 31℃~112℃. The effects of gas and liquid compressibility on two phase viscosity and pressure drop have been illustrated.N_2 foam fracturing fluid is shear thinning and can be described by power law model, the effective viscosity decreases with the increase of shear rate and temperature, while increases with the increase of pressure and foam quality, the influences of temperature and foam quality are stronger than pressure, and the rheological parameters change with temperature and foam quality by the power rule. An attempt has been made to obtain the connection between pressure, temperature, foam quality and rheological properties, which provide the basis for reasonable selections of fracturing parameters accurate evaluation.