摘要
针对深水井控的特点,建立了多相流控制方程,给出了温度场方程和水合物生成热力学方程,并给出了不同工况下求解上述方程的定解条件和离散方法以及求解步骤。数值计算表明:随着关井时间的增加,环空内的温度越接近环境温度,水合物的生成区域越大;随着压井排量的增加,天然气水合物的生成区域变小,可适当提高流量使水合物的生成区尽量远离海底,减小防喷器管线被水合物阻塞的危险;由于节流管线摩阻的原因,与钻进时相比,压井时水合物的生成区域会变大,且随着节流管线内径的减小,水合物的生成区域会变大;随着抑制剂浓度的提高或钻井液入口温度的升高,天然气水合物的生成区域也随之变小。
The governing equations of multiphase flow were established by analyzing the characteristics of deep water well control.The temperature field equations were obtained based on conservation of energy and a hydrate formation equation was proposed.The boundary and initial conditions of well control,discrete strategy and iterative steps were imposed for solving the equations.The numerical simulation shows the following results.Annular temperature gets close to ambient temperature and the hydrate formation region becomes large with increasing shut time.The hydrate formation region becomes small with circulation rate of well killing.Therefore,it is possible to bring the hydrate formation region away from this place by increasing circulation rate.And it is a feasible method to prevent BOP lines to be blocked by hydrate plugging.Due to friction of choke line,the hydrate formation region is larger during well killing than that during normal drilling,and the region becomes large with decreasing choke line size.The hydrate formation region is going to get small with increasing inhibitor concentration or entrance temperature of drilling fluid.
出处
《应用力学学报》
CAS
CSCD
北大核心
2009年第2期224-229,共6页
Chinese Journal of Applied Mechanics
基金
国家“863”计划重大项目课题(2006AA09A106)
国家自然基金(50874116)
教育部博士点基金(20060425502)
关键词
深水井控
天然气水合物
多相流控制方程
温度场
热力学方程
deep water well control,natural gas hydrate,multiphase flow governing equation,temperature field,thermodynamics equation.
