Abstract:

There are several sets of formation pressure systems in Y structure of block X in Bohai Sea. Shahejie Formation and its upper strata are sedimentary undercompacted layers. dc index method is adopted to monitor formation pressure. The Mesozoic buried-hills are widely distributed in medium acid volcanic rocks, which are non-sedimentary underpressure layers. The formation pressure monitoring method of Sigma index is used to monitor the formation pressure. The real drilling shows that the formation pressure monitoring method of dc index has good applicability in the formation profile pressure monitoring dominated by sand and mudstone. The formation pressure monitoring method of Sigma index has a good application effect in the non-sand mudstone formation profile pressure monitoring, and the combined application of the two provides effective technical support for the smooth drilling. The application of Sigma index formation pressure monitoring method in deep and ultra?deep layers effectively improves the accuracy of the deep and ultra?deep layer pressure monitoring technology while drilling. The practical application shows that the results of formation pressure monitoring while drilling are in good conformity with the measured formation pressure results, and the formation pressure monitoring method of Sigma index has the value of popularization and application in deep and ultra-deep formation.

Key words: Deep formation, Undercompacted formation, Non-undercompacted formation, dc index method, Sigma index method

摘要：

渤海X区块Y构造存在多套压力系统，沙河街组及上部地层为沉积欠压实性地层，采用dc指数的地层压力监测方法监测了地层压力；中生界潜山广泛分布中酸性火山岩，为非沉积欠压实地层，采用Sigma指数的地层压力监测方法监测了地层压力。实钻结果表明，在砂泥岩为主的地层剖面压力监测中，dc指数的地层压力监测方法具有较好的适用性；在非砂泥岩为主的地层剖面压力监测中，Sigma指数的地层压力监测方法具有良好的应用效果，两者的配合应用为钻井的顺利进行提供了有效的技术支持。Sigma指数的地层压力监测方法在深层?超深层井中的应用，有效地提升了深层?超深层井随钻地层压力监测的准确性。实际应用结果表明，随钻地层压力监测结果与实测地层压力结果相吻合，Sigma指数的地层压力监测方法在深层?超深层井具有推广应用价值。

关键词: 深层, 欠压实地层, 非欠压实地层, dc指数法, Sigma指数法