Based on calculation of hydrocarbon generation and expulsion through TSM basin simulation

potential field analysis

and oil/gas migration channel modeling

dynamic and quantitative resources calculation methods are proposed for plays and structural zones in an attempt to determine the migrated and accumulated resources and pin down their locations

so as to realize dynamic assessment of resources.Zhentong depression in Subei basin is divided into four plays(fault terrace

inner slope

hinge belt

and outer slope) and 11 structural zones according to hydrocarbon expulsion potentials and structural features

and these methods are used to quantitatively calculate the total volume of oil and gas migrated and accumulated in the main targets across all the plays since the deposition of the Sanduo Formation(35.2Ma).The calculation indicates that the main period of hydrocarbon migration and accumulation is from the deposition of the Yancheng Formation(23.2Ma) till present.During this period

about 9.98Mt of hydrocarbons migrated from Sanduo Formation and accumulated in fault terrace play

accounting for 52.0% of the total hydrocarbons generated by this formation.While in the inner slope

the volume from the Dainan Formation is about 21.59 Mt(51.0% of the total)

from the 3

rd

member of Funin Formation is 145.19Mt(48.5% of its total).The absolute magnitudes of hydrocarbons migrated and accumulated in the fault terrace play are about 61.70 Mt from the 3

rd

member of Funin

25.39 Mt from Taizhou Formation

and 19.70 Mt from the 1

st

member of Funin Formation.Therefore

in respect of quantitive resource assessment

the exploration focus shall be put on the 3

rd

member of Funing Formation and Sanduo Formation in the fault terrace play

while in the inner slope play

it shall be put on the Taizhou Formation

1

st

and 3

rd

members of Funin Formation

and Dainan Formation.