Abstract:

Yinggehai Basin is a fault-depressed basin developed on the basement of PreTertiary System.In vertical,the basin shows generally transgressive filling sequences.The basin underwent three deposition processes since Eocene.T_g～T₇₀(before 28 Ma)was rapid subsidence period,the total rate of descent was 600 m/Ma;the total descent rate of T₇₀～T₃₀(28 Ma～5.2 Ma)period was 500 m/Ma;that of T₃₀～ present day (5.2 Ma～ present) is 600 m/Ma.The amount of subsidence caused by tectonics is about 1/2～1/4 of the total amount;the rest is mainly related to isostatic subsidence.It is proposed that deltaic,beach and turbidite sandbodies are the main mediumdeep reservoirs in the basin;the distributary channel sandbodies deposited during Huangliu Formation may be favourable reservoirs.

Key words: filling sequence, subsiding period, descent rate, reservoir, Yinggehai Basin