一种水基抗温钻井液的高温流变性研究

Research on high temperature rheological properties of water-based temperature resistance drilling fluids

关键词:  钻井液  高温  流变性  流变仪 

Key words:  drilling fluid  high temperature  rheological property  rheometer

摘要:

钻井液的高温流变性对于深井、超深井快速、安全地钻进具有重要影响,而高温老化冷却后测定的钻井液流变性能并不能代表高温条件下的流变性能。因此采用Fann50SL型高温高压流变仪对抗高温水基钻井液体系的高温流变性进行了研究,求得其流变参数,最高实验温度达到了220 ℃。综合考察了温度、密度、聚合醇、聚合物和盐等因素对钻井液体系流变性的影响。结果 表明,塑性黏度与温度间遵从二次函数关系,温度升高,塑性黏度呈指数规律下降,且体系的密度越大,受温度的影响越大；在低温段(～150 ℃)加入聚合醇和聚合物会对体系流变性产生明显影响,高温段(150～220 ℃)影响较小；盐对高密度钻井液体系流变性的影响明显大于低密度钻井液体系。该研究可为现场施工中钻井液体系流变性的调控提供指导。 

Abstract:

High temperature rheological properties of drilling fluid have important influences on fast and safe drilling in deep or ultra-deep wells. Rheological properties of drilling fluid after high temperature aging and cooling do not represent the rheological properties at high temperature conditions. High temperature rheological properties of water-based temperature resistance drilling fluid system were studied with the Model 50SL high-temperature high-pressure rheometer, so the rheological parameters were obtained, and the maximum experimental temperature reached 220℃. The effects of temperature, density, polyalcohol, polymer and salt on rheological properties of drilling fluid were studied. The results show that plastic viscosity and temperature complies with the relation of quadratic function. Plastic viscosity decreases exponentially with increasing temperature, and the higher the density, the greater influence by temperature. In lowtemperature range(less than 150 ℃), polyol and polymer have obvious influence on rheological properties of drilling fluid system, and less influence in high temperature range (150-220 ℃). Salt has more obvious influence on rheological properties of high density drilling fluid system. The study provides guidance for regulating rheological properties of drilling fluid system in field operation.