考虑油气和水合物相变、岩屑以及地层产出等参数的影响,针对井筒与隔水管,建立深水钻井井涌期间的多相流动控制方程组,采用数值方法对方程组进行求解并编制相应软件,对深水井涌的流动过程进行动态模拟,分析井筒气相体积分数及溢流参数随溢流时间的变化规律,讨论地层渗透率、地层与井底初始压差以及水合物生成与分解对溢流参数的影响。结果表明:溢流时间越长、地层渗透率越大、地层与井底初始压差越大,则泥浆池增量越大,井底压力降低越明显,井控难度越大;水合物生成与分解对井筒及节流管线的流动有影响,尤其对已存在的较多水合物采取措施促使其分解时,对节流管线内的气相体积分数影响很大,进而影响压力分布及节流压力的调节。
Considering the effects of gas-oil and gas-hydrate phase change,cuttings and formation fluids,multi-phase flow models in the wellbore and riser were established under the condition of kicks process in deepwater drilling,and the solving method was acquired.Well control software was developed and the dynamic simulation of kicks in deepwater drilling was done.The well kicks parameters in deepwater were calculated using the software and the variations of gas volume fraction and the overflow parameters with the continuance time of kicks were analyzed.The influences of many factors on the well control parameters were also studied,such as permeability,initial pressure difference between the wellbore bottom and stratum,and formation and decomposition of the hydrate.The simulation results show that mud pond incremental and bottom pressure drops velocity were increased with kicks time,permeability and initial pressure difference increasing,and well control difficulties were added consequently.The flow patterns in wellbore and riser were influenced by the formation and the decomposition of the hydrate.The gas volume faction was influenced effectively by the decomposition of the hydrate when there were large amounts of hydrate in blowout preventer(BOP) or lines.And the pressure distribution in wellbore and the adjustment of the choke valve were also affected subsequently.