BLOCK 2C区块含有多套压力体系, 油气非常活跃, 钻井液密度窗口窄, 采用常规钻井技术钻井时, 在前几口井中均出现稍低就涌、 稍高就漏的情况. 不间断循环钻井系统 ( CCS系统) 可以在接单根或立根期间保持钻井液的不间断循环, 能够有效解决窄钻井液密度窗口的钻井问题. 为此, 在BLOCK 2C区块的Canteen-A09井中应用CCS系统. 应用结果表明, 钻进过程中井内岩屑循环较彻底, 较好地控制了循环当量密度, 使得井内压力得到较好的控制, 平稳通过了窄密度窗口地层; 没有开泵和停泵引起的压力波动, 也减少了漏失的可能性; 测井时仪器顺利到底, 没有出现反复通井的情况, 最终提前4d完钻, 节约一百余万美元.%With multiple pressure systems, Block 2C is characterized by active oil and gas production and narrow window of drilling fluid densities. Application of conventional drilling techniques in some wells experienced kicks at lower pressures and lost circulation at higher pressures. With capacity to maintain continuous circulation during installation of single joints or standpipes, the continuous circulation system ( CCS ) can effectively solve problems related to narrow windows for densities of drilling fluids. The CCS was applied in Well Canteen-A09 of Block 2C. The results show that cuttings are circulated thoroughly during drilling, and ECD functions properly to keep internal pressure properly controlled, so that the tool penetrates formations with narrow density window. In ad-dition, elimination of pressure fluctuations induced by pumping operations effectively reduces possibility of lost cir-culation. During logging operations, relevant instruments are deployed properly without requiring repeated drifting operations. With drilling operations terminated 4 days ahead of schedule, over one million US dollars have been saved in drilling cost.
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