Dongpu depression is a typical salt-lake basin in Bohai Bay region.Two sets of halites have been deposited in the two Paleogene depositional cycles.The halites in the 3rd member of Shahejie Fm (Es
3
) can be divided into three sub-units: the 4th sub-member (Es
3
4
)
3rd sub-member (Es
3
3
)
and 2nd sub-member (Es
3
2
)
which mostly distribute near the central uplift belt in northern Dongpu depression. Halites have been compacted and become very tight
which would become barriers and result in higher geotemperature and formation pressure in the underneath stra-ta
and would be favorable to the transformation of organic matters in the underlying source rocks into oil and gas. Meanwhile
halite is also a good cap rock
and would be in plastic state under high temperature and high pressure condition. Because of the barrier and deformation of the halites
multiple reservoir types related to halites have been formed
such as graben-like anticlinal oil and gas reservoirs in the upper part of the halite
oil and gas reservoirs laterally blocked by halite
anticlinal oil and gas reservoirs under the halites and lithological oil and gas reservoirs. As a result of the shifting of halite depocenters during the deposition of Es
3
there are always sandstones under the Es
3
4
Es
3
3
and Es
3
2
halites
which would become relatively good combination of reservoir and cap rock
and even result in very rich accumulations of oil and gas beneath the halites in central uplift belt. Although the Es 1 halite is thin
its distribution area is large and it would still play the key role in the hydrocarbon accumulation in the 2nd member of Shahejie Fm (Es
2
). Much attention should be further paid to those areas
such as deep horst belt under the Es
3
4
halites in eastern Wenliu
the Es
3
2
Wen 93 fan between the halites in eastern Wenliu
the Qianliyuan sag in eastern Dongpu depression and Haitongji sag in western Dongpu depression.