| The Oubei-Dawan, belonging to the eastern depression of Liaohe basin, is a new exploration field found recently in Liaohe basin. There are various reservior and oilfield types. The objectives of this study are mainly clearing about the petroleum pools' distribution whose features like the well Ou39 and lava petroleum pools', and directing the future explorition in the middle area of the eastern depression using the result of this study.. This paper, applying Sequence Stratigraphy, through studying on sedimental faices and running the sedimental model, obtained the reservior's distributing feature of the whole depression whose centre is the well Ou39. This work obtained the distribution scenario of Ou39's fan-delta's sandbody and the favrable-explorating area to afford the evidences for production.It is necessary to give the structural background of the studied area, especially, the concept of the structural style is also important to the study of the development to the deposition and sedimentary system.It is most important to define the sequence boundary and the maximum flood surface for sequence classification. Sequence boundary is the turn-point of the falling and rising of the baselevel. The maximum flood surface is the turn-point of the rising and falling of the baselevel. Once these two surfaces are defined, a intergrated sequence can be classificated. The principle of this area's sequence classfication is using seismic data to classificate the third-sequences. A middle good-quality reservior cycle is a fourth-sequence, and a short cycle is a fifth-sequence. Based on it, we subdivide the third member of Shehejie Formation into 3 third-sequences and 12 fourth-sequences.According to the cores and seismic data, the most important facies is fan-delta in this area, mainly developing in the top member and the bottom member developing turbidite-fan. Major faults' moving intensively led to deep strata sinking. The depositional centre was still in the centre techtonic zone. The lacus continuously extended. Most of this area was shallow-lake, semi-deep lake and deep lake sedimentary environment, except that the area around the well Ou44 was a set of steep-slope fan-delta and the Dawan area was a set of small-scale fan-delta.There were fan-delta, turbidite-fan, shallow-lake, shore-marsh, semideep-lake and volcano-debris facies. In the area of the well Ou39 and Ou44, fan-deltas developed both in the middle and the top strata of the third member of the Shahejie Formation. The former lies in the north area of the well Ou39, belonging to the steep-slope style which was controled by inertia factor. Its range is relatively small. The latter's range is broad, belonging to the gentle-slope style. The bottom stratum developed a set of turbidite-fan. The rule represents the tectonic evolution feature's controling to the depositional infilling styles and facies' distribution. In Dawan area, the top and the middle strata of the Shahejie Formation also developed a set offan-delta sediment similar to the bottom of the Shahejie Formation, but the scale is significantly smaller.Through predicting and estimating the third member of Shahejie Formation, this paper pointed that the fan delta front of the top third member Shahejie Formation in Oubei area is a good-quality reservior sand-body, which was proved by the practical production. The upper fan-delta and the lower turbidite-fan sand-body are also good-quality reserviors. The further study on the fan is very important for the future explorition. The fan delta front around the well Tie 16 is worse than the bottom Shahejie Formation's fan. The reservior's quality in the Dawan area is relatively bad.
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