CO2泡沫压裂液的流变性及井筒摩阻计算方法研究

进行了CO2泡沫压裂液的室内配制、流变性测定以及摩阻计算方法研究。室内实验中观测了CO2泡沫压裂液的形成、动态变化、泡沫结构,测定了CO2泡沫压裂液的流变性,发现其属于假塑性非牛顿流体。推导了CO2泡沫压裂液在油管内流动的摩阻计算公式,计算了不同管径、不同排量、不同泡沫质量时的摩阻曲线,进行了井筒内CO2泡沫压裂液摩阻压降实测,与计算方法相比误差在工程应用允许范围内。该研究所得到的CO2泡沫压裂液流动特性、摩阻压降计算方法、经验图版等,可供工程应用中参考。

Study on Friction Calculation for CO2-Foam Fracturing Fluid in Conditions of High Temperature and High Pressure

The fact that lacking of characteristic knowledge on CO2-foam fracturing fluid and friction computation methods has been the major problem constringes the application for CO2-foam fracturing fluid in the oil field.So laboratory measurement and study are made on preparation of CO2-foam fracturing fluid,rheological measurement and friction computation methods in this paper.The performance changes and foam texture of CO2-foam fracturing fluid are observed by laboratory experiments.By measuring data of rheological,it is proved that the rheological property of CO2-foam fracturing fluid is according with pseudoplasticity Bingham plastic fluid.Friction calculation formula is derived for the CO2-foam fracturing fluid.Friction curves are obtained in different caliber,different circulation flow rate and different foam quality.Field measurement on foam friction in wellbore is also made.Comparing with calculated value,the error is in reasonable limits after correction by the coefficient of 1.25.The result of study on flow behavior and rheological pattern of CO2-foam fracturing fluid,as well as friction computation method for wellbore can be used and referred in project application.