深井气侵关井引发的井筒多相水击压力特性研究  

Research on water hammer pressure in multiphase flow along wellhole in shutting operation

作　　者：罗朝东 

机构地区：[1]中石化西南工程有限公司钻井工程研究院,德阳618000

出　　处：《应用力学学报》2018年第1期218-221,共4页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(51274170);国家重大专项(2011ZX05022-005-005HZ)

摘　　要：结合小扰动理论,建立了深井气侵关井引发的井筒多相水击压力模型。利用有限体积及特征线等数学方法,提出了基于离散网格求解井筒多相水击压力方法。结果表明:气侵量、井深及关井时间等参数均对井筒多相水击压力影响显著;井底气体的侵入,大幅降低了环空压力,增大了井筒空隙率,减小了井筒水击波速,延缓了井底水击压力峰值点出现时间;随井底气侵量增大,井筒多相水击压力呈减小趋势,气侵量从1.46m3/h增至4.14m3/h,水击压力高峰值大幅度降低;随井深增大,水击压力呈减小趋势,井深1550m同井口处相比,水击压力高峰值减小86.63%;随关井时间延长,水击压力呈减小趋势,关井时间延长10s,水击压力高峰值减小44.46%。Combined with small disturbance theory,the multiphase flow model of water hammer pressure is established in a deep well during shut-in operation. With the finite volume and characteristic line methods, a method for solving the water hammer pressure is proposed based on discrete grids in multiphase flow along annulus. The results are consistent with the existing data. The results show that the gas invasion rate, well depth and shut-in time have great effects on water hammer pressure in multiphase flow along annulus. With the invasion of the gas at well bottomhole in deep well, the annulus pressure is reduced greatly, the void fraction increases, water hammer pressure wave speed is reduced along the annulus, and the pressure response time of water hammer pressure is prolonged at the bottomhole. With the increase of gas influx rate, the water hammer pressure decreases, the gas-cutting increases from 1.46 m3/h to 4.14 m3/h, then water hammer pressure peak value decreases remarkably. With the increase of well depth, the water hammer pressure decreases, and with the depth of 1550 m compared to wellhead, water hammer pressure peak value is decreases to 86.63%. With the extension of shut-in time, water hammer pressure shows a decreasing trend, and when shut-in time is extended to 10 s, water hammer pressure peak value decreases to 44.46%.

关 键 词：深井 多相流体 关井 水击压力 压力响应时间 

分 类 号：TK037[动力工程及工程热物理]