深水井控中节流管线摩阻分析及压井方法

在海洋深水钻井中，防喷器组一般安装在海底，当发生井涌进行压井作业时．由于节流管线较长、内径较小，钻井液在节流管线内存在高摩阻损失，作用在井底的压力往往大于地层的破裂压力．从而引起压井过程的复杂化，甚至造成压井作业的失败。介绍了一种新的压井方法附加流量法，在返出的节流管线流体中混入低密度流体，降低节流管线内流体的粘度和密度，从而实现安全压井；详细介绍了压井方法和步骤。数据分析表明，通过对压井参数进行优化选择能够降低节流管线中的压耗。

A Method of Killing Well and Analysis on Choke-Line Friction Losses for Deepwater-Well Control

In deepwater drilling, a BOP stack is usually located at seabed level. When it is necessary to kill a well, the friction loss in choke line is very high because of its large length and small inner size. Thus, the bottom-hole pressure may be larger than formation fracture pressure, which will cause complex killing operation and even lead to a failed one. This paper presents a novel killing method named additional flux, mixing low density fluids into returned fluids from the choke line and thus reducing the viscosity and density of fluids in the choke line, then a safety killing operation can be achieved. This killing procedure is introduced in detail. Data analysis indicate that optimizing killing parameters can reduce the friction losses in choke line.