深水钻井防喷器温度场数值模拟研究

深水防喷器所处环境为低温高压,如有气侵出现,容易在防喷器位置生成天然气水合物,阻塞防喷器,产生井口安全隐患。为此,结合深水钻井工况,建立了深水钻井条件下闸板防喷器与环形防喷器的三维空间模型,并利用Fluent软件进行了温度场数值模拟,得到了防喷器不同位置的温度场分布。在此基础上,结合天然气水合物生成条件分析了防喷器的温度场分布,以及加热管对防喷器温度场的影响规律,并优选了加热管的布置位置。结果表明,在模拟环境条件下,闸板防喷器横向位置依靠防喷器通径内壁加热即可满足天然气水合物预防要求,在纵向侧面1/4处布置加热管效果较好;管线数量对环形防喷器温度场的影响很大,为满足温度高于天然气水合物形成温度的要求,可以将优化加热管数量与保温措施结合起来进行。 

Numerical Simulation of Temperature Distribution of Blowout Preventers in Deepwater Drilling

In case of gas cutting,hydrate is likely to form in deep water blowout preventers due to low temperature and high pressure and block the blowout preventers,which might compose safety threat at wellhead.Combining deepwater drilling conditions,3Dmodels of ram preventers and annular blowout preventers in deepwater drilling condition were built-up,and numerical simulation of temperature field was performed to obtain the temperature distribution across the preventer.Then optimal heating locations of pipes were chosen according to the effect of heating pipe on blowout preventer temperature field.Result showed in the simulated temperature that heating by annulus itself in the transverse direction of the ram BOP,and heating pipe around 1/4part of the longitudinal section could meet the requirements of preventing gas hydrate formation.Quantity of heating pipes has large influence on the temperature field of annular BOP.Optimization of pipe quantity and insulation combination should be considered to keep the temperature at annular BOP over hydrate formation temperature.