Diagenetic Alteration Modes of the Deep Formation of Paleogene of Chezhen Depression,Bohai Bay Basin

The deep buried clastic formation of Paleogene is an important hydrocarbon reservoir in the Chezhen depression.There are two types of diagenetic alteration modes in it.The first mode is weak compaction, strong cementation,fracturing and weak dissolution in the sandstone and conglomerate on the steep slope of the depression.The reservoirs are cemented mainly by carbonate minerals strongly。