南海深水钻井井涌余量主控因素分析

深水钻井中,由于深水段的影响,上覆岩层压力低,钻井液密度窗口窄,对井涌余量的预测精度提出了更高的要求。井涌余量受井涌强度、套管鞋承压能力、侵入流体性质等多种因素影响,其应满足在最危险工况下能进行安全压井的要求。针对南海深水井进行计算分析,得到不同因素对井涌余量的影响规律,提出深水钻井井涌余量分析应注意的问题,为深水钻井设计和现场作业提供了参考依据。研究结果表明,深水钻井中,需充分考虑不同因素对井涌余量的影响,尤其是窄密度窗口下,其计算精度将影响井身结构和套管下深。

Main control factors of kick tolerance for deepwater drilling in South China Sea

In the deepwater drilling, affected by the deepwater section, the overburden pressure is low and the drilling fluid density window is narrow, so higher requirements are raised for the prediction precision of kick tolerance. The kick tolerance is affected by multiple factors, such as kick strength, casing shoe bearing capacity, and intrusive fluid property, and should meet the requirement of safe well killing under the most dangerous working conditions. After the calculation and analysis of deepwater wells in the South China Sea, the effects law of different factors on kick tolerance is figured out, and the notices in kick tolerance analysis of deepwater drilling are raised, so as to provide a reference basis for the deepwater drilling design and site operation. According to the research results, in the deepwater drilling, the different factors effects on the kick tolerance should be fully considered. In particular, in the narrow density window, the calculation precision will affect the wellbore structure and casing lowering depth.