中文摘要：

为准确掌握高温高压条件下环空多相流的流动特性，基于井筒多相流、传热学理论，充分考虑循环流体物性参数随温度压力的变化，建立了适用于深井、超深井的井筒多相流全瞬态温度压力场耦合模型，并提出了迭代求解算法，以塔里木油田某深井为例分析了井筒瞬态温度、压力耦合变化规律。结果表明：循环8h后井底钻井液的密度由1360 kg／m3升至1460 kg／m3，塑性黏度由8.6 m Pa ·s升至13.8 m Pa· s ；开始循环时井底压力迅速降低，循环0.2h时降至最低，然后逐渐升高，最后趋于稳定；井底钻井液的密度和塑性黏度随循环时间增长而增大；气侵量对井底压力的影响最大，钻井液地面密度、排量、井口回压次之，钻井液地面塑性黏度的影响最小。分析结果可为深井、超深井水力参数设计提供理论指导。

英文摘要：

To accurately identify the features of annular multiphase flow in high temperature high pres‐sure （HTHP） conditions ,a fully transient temperature and pressure coupling model for multiphase flow in deep or ultra‐deep wells was established according to the theory of wellbore multiphase flow and heat transfer .Considering the changes of physical parameters of circulating fluid with temperature and pressure , and the iterative algorithm was proposed .In this paper ,a deep well in Tarim Oilfield was analyzed for the wellbore transient temperature and pressure coupling .The results indicated that the drilling fluid density at bottomhole increased from 1 360 kg/m3 to 1 460 kg/m3 ,and the plastic viscosity increased from 8.6 mPa· s to 13.8 mPa· s after circulating for 8 hours .Both the drilling fluid density and the bottomhole plastic viscosi‐ty increased over the circulating time ,and further ,the bottomhole pressure dropped linearly at initial circu‐lation and then to the minimum at 0.2 h .Later ,it increased logarithmically and tended to be finally stable . In view of the impact on bottomhole pressure ,the factors are were prioritized in a descending order as fol‐lows ：gas influx ,surface drilling fluid density ,displacement ,wellhead back pressure ,and surface drilling fluid plastic viscosity .An analysis of the results could provide certain theoretical guidance for the hydraulic parameter design of deep and ultra‐deep wells .