Study Of The High-resolution Sequence Stratigraphy And Sedimentary Microfacies In Ming1Fault Block Of Wenming Village Oilfield

The Wenming village oilfield is located at the north central uplift belt, it is acomplicated fault oil field in the context of vault and the migration of oil and gas iscontrolled by fault block. As to the existentproblems in oil field development and thecharacteristics of complicated structure and abundant reservoir, the comprehensiveresearch method of combination macro-examination with micro-examination,combination qualitative with quantitative is applied to establish the sequence stratusframes in Ming1fault block of Wenming village oilfield, on the base of ReservoirSedimentology, Petroleum Geology, Sequence Stratigraphy. Then further research ofindividual well section of sedimentary facies and the distribution of sedimentaryfacies is needed to establish the whole area sediment model, which provides a newway of thinking and method to make further improvement on oil recovery factor.Applying the theories and methods of different hierarchical base-levelcycles, combined with tectonic background in Wenming village oilfield, byutilization of well drilling, well logging,rock core, seismic information, thepaper goes on the classification of base-level cycles, then Ming1fault block isdivided into two long-term base-level cycles, eight medium-term base-levelcycles, and thirty-two short-term base-level cycles. Based on the classificationof base-level cycles, using cycle isochronous correlation technology, thehigh-resolution sequence stratigraphic frameworks of lower strata Es2to upperstrata Es3are established in Ming1fault block.Combined with information of rock core, well drilling and well logging,individual well section of sedimentary facies is needed, then the further job is toresearch the temporal and spatial evolution, sand body spreading regularity. Thispaper shows that it is terminal fan sedimentary system at lower strata Es2, the sandbody can mainly be found in distributary channel and channel overflow deposits,inverted point-bar sand is rather poorly developed. This period has a semiarid climate,and the whole lake basin is over the surface of the earth, source supplied clasticmaterials from north, northwest, northeast in study area form distributary channel and channel overflow sand body. This period is mainly developed middle subfacies ofterminal fan facies which near-end is chiefly distributary channel deposits andsuspension deposits, distributary channel sandstone is interbedded with overflowsandstone. At far end of middle subfacies far way from the distributary channel,density of river course gets small and thickness of sand body becomes thin, sedimentsare made primarily of far overflow sand body and find-grained sediments in alluvialmaterial.The research also concludes that it is fade adjustment of Dongpu Depression atupper strata Es3, is the gradually process of lake basin atrophy. Then Lanliaofracture which controls the basin subsidence weakens in intensity, the worm anddank climate becomes dry while lake basin uplifts entirely and the lake shallows. It isshallow delta depositional system at upper strata Es3, moreover, source suppliedclastic materials is from north and west in research region. The major type of sub-faceis deltaic front, clastic materials are acted upon by forces of river and shallow lake,the main reservoir sandstone is deposited during under-water distributary channeldeposits and suspension deposits. In comparison with typical delta deposit, themagnificent features of shallow deltaic front sub-face are that distributary channelextends relatively far and it’s often over the water surface transformed by sheetsandstone.