| The application of sequence stratigraphy and technology provides a new methodfor oil and gas-bearing basins exploration. It is also an effective and advanced methodto identify and predict elusive reservoirs. Based on sequence stratigraphy and existing oil and gas exploration experiences,with seismic, drilling, well-logging, core data and other available achievements, thisdissertation is focused on the study of sequence stratigraphy and sedimentary of Sha3layer, western Huimin Dpression, sequence boundary was confirmed, system tractswere divided, sequence stratigraphy framework was established. This paper alsodiscusses the characteristic of inner sequence ingredients, analyzes the depositionalsystems and facies in the sequence framework, summarizes the time-spacedistributing disciplines. Moreover, combined with regional structural conditions andfilling characters, the forming conditions and types of potential subtle traps wereanalyzed, and favorable reservoirs were forecasted. Combined with well-drilling, logging, seismic data, core data, outcrops and othergeological information, Sha3 layer was divided into 4 sequences and 7 tracts, then thehigh-resolution sequence framework is established. Based on the dichotomy systemtracts, elaborate depositional system and facies were discussed, holding that lacustrinedeposit, fan-delta facies, delta facies, subsea apron facies and turbid fan faciesdeveloped in Sha3 layer. With the shifting base level cycles, the preceding systemsinheriting-developed, which determined the distribution of the sub-structural units andfilling evolution. The thesis also points out that lower and middle Sha3 layer is themost favorable sequence for depositional trap. Especially, base level fall half-cycle isthe favor sequence position where subsea apron facies and turbid fan facies developed.Integrated with structural evolution and seismic attribute characters of this region,eight favorable depositional traps were predicted.
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