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

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