Precise managed pressure drilling system can effectively solve the complex drilling problem of narrow density window with overflow and leakage in the same drilling section and improve the drilling efficiency. But the precise managed pressure drilling system did not form in our country. Therefore, on the basis of comparative analysis of the foreign Weatherford, Schlumberger and Halliburton MPD technical characteristics and according to the MPD theory,the PCDS-I based on constant bottom hole pressure was developed with independent intellectual property rights. This paper introduced PCDS-I system components, their characteristics and functions. The precise control method was explained, and the field test in Well Penglai-9 was introduced. The results showed that PCDS-I precise managed pressure drilling system worked stably without any fault in different types of working conditions in the field,and PCDS-I achieved the target for constant bottom hole pressure control and micro-flow control. The accuracy of back pressure control in all types of working conditions was less than 0. 5 Mpa. The technical performance meets the requirements of designs.%精细控压钻井技术能有效解决窄密度窗口钻井涌漏同存的问题,提高钻井时效,但国内还没有成熟的精细控压钻井系统.为此,在对比分析国外Weatherford、Schlumberger和Halliburton三大公司精细控压钻井系统技术特点的基础上,根据控压钻井原理研发了具有自主知识产权的、基于井底恒压的PCDS-Ⅰ精细控压钻井系统.介绍了PCDS-Ⅰ精细控压钻井系统的组成及各组成部分的特点和功能,阐述了该系统实现精细控压钻井的工艺方法,并在四川蓬莱9井进行了精细控压钻井试验.结果表明:PCDS-Ⅰ精细控压钻井系统整体运行稳定、无故障,经受住了现场工况的考验,实现了恒定井底压力控制和微流量控制,全工况回压控制精度达到0.5 MPa,技术性能指标达到了设计要求.
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