基于非等温三相流模型的欠平衡钻井井底压力预测

考虑欠平衡钻井中钻屑的影响以及由于地层和钻井液之间热量传递导致的温度变化,应用气-液-固三相流模型来模拟井筒流体,计算井筒温度和压力分布,分析不同参数对环空内流体压力和温度分布的影响.研究表明,与两相流模型及其他考虑地温梯度的三相流模型相比,考虑传热的非等温三相流模型能够更加准确地预测欠平衡钻井井底压力.井筒内黏性耗散...

Modeling and simulation of non-isothermal three-phase flow for accurate prediction in underbalanced drilling

The present study aims at investigating the effect of temperature variation due to heat transfer between the formation and drilling fluids considering influx from the reservoir in the underbalanced drilling condition.Gas-liquid-solid three-phase flow model considering transient thermal interaction with the formation was applied to simulate wellbore fluid to calculate the wellbore temperature and pressure and analyze the influence of different parameters on fluid pressure and temperature distribution in annulus.The results show that the non-isothermal three-phase flow model with thermal consideration gives more accurate prediction of bottom-hole pressure(BHP)compared to other models considering geothermal temperature.Viscous dissipation,the heat produced by friction between the rotating drilling-string and well wall and drill bit drilling,and influx of oil and gas from reservoir have significant impact on the distribution of fluid temperature in the wellbore,which in turn affects the BHP.Bottom-hole fluid temperature decreases with increasing liquid flow rate,circulation time,and specific heat of liquid and gas but it increases with increasing in gas flow rate.It was found that BHP is strongly depended on the gas and liquid flow rates but it has weak dependence on the circulation time and specific heat of liquid and gas.BHP increase with increasing liquid flow rate and decreases with increasing gas flow rate.