无隔水管钻井泥浆举升系统参数计算

Parametric computation of mudlift system in riserless drilling

为解决深水钻井过程中遇到的难题,无隔水管钻井技术(RMR)使用单梯度泥浆,但通过将海底泵的入口压力减小到接近海水静液压力来模仿双梯度,系统在钻井过程中不再采用隔水管,岩屑和钻井液经一条小直径回流管线返回钻井平台。根据无隔水管钻井泥浆举升系统的参数要求和两相流理论,确定了举升系统的参数计算方法,对500 m水深举升系统参数进行计算和研究,分析了岩屑参数对举升系统参数的影响,得出颗粒的尺寸、体积分数是举升系统水力设计需要考虑的关键参数。研究结果为无隔水管钻井泥浆举升设备的设计提供了理论依据。

In order to solve the problems associated with complex deepwater environment,the riserless drilling system has been developed.As ocean riser is eliminated in this technique,cutings and mud are returned to the drilling platform through a small diameter hose from the seabed by the subsea pumps.According to parametric requirement of mudlift system and two-phased flow theory,parametric computation of mudlift system was conducted,and provided theoretical basis for the design of mudlift equipment of the riserless mud recoverydrilling.In the light of the above stated computational method,computation and research of parameter of mudlift systerm in 500 m water depth were carried out ,and parameter of cuttings＇s influnce to parameters of mudlift systerm was analysed.