氮气泡沫压裂液体系在水平管段中的流动规律

Flow Pattern of Nitrogen Foam Fracturing Fluid in Horizontal Pipe

根据泡沫压裂液体系含有气体和液体两相这一特性,设计了一套室内泡沫流体管式流变仪,进行了泡沫压裂液体系在水平管段的流动规律研究,得到了泡沫压裂液体系在实验管段的微观结构;并对泡沫质量对泡沫压裂液体系的流变性影响进行了研究.实验结果表明,泡沫压裂液体系随着泡沫质量的增加,管路中的压降先增加后减小;并且泡沫质量较小时很难得到稳定的泡沫;泡沫质量在40％～75％之间能得到稳定的泡沫;用幂律模型研究泡沫压裂液的流变特性,得到泡沫压裂液体系的流变方程.结果表明,随着泡沫质量的不断增加,泡沫压裂液体系的稠度系数不断增加,流变指数不断减小;并且随着剪切速率的增加,表观黏度不断降低,对于研究泡沫压裂液在井筒中的流动具有一定的价值.

Foam fracturing fluid has both gas and liquid. According to this characteristic, the pipe rheometer is designed to study the flow pattern of nitrogen foam fracturing fluid in horizontal pipe. The microscopic structure of foam fracturing fluid in the horizontal pipe is got, and studied its rheological properties. Results show that, with the foam quality increasing, the pressure loss in the pipe will go up first, and then go down. The foam is unstable as the foam quality is in a low level. The foam will keep stable when the foam quality is between 40% and 75%. The foam in the horizontal pipe behaves like a power-law fluid. With the foam quality increasing, the consistency coeffi- cient increases, while the rheological index decreases. Moreover, as the shear rate increases, its apparent viscosity decreases. These experiments have certain value in the study of foam fracturing fluid flow in the well.