Research On Sequence Stratigraphy Of The Groups In The Northwest Of Beier Depression

In this paper,guided by the theories of sequence-stratigraphy,sedimentology,petroleumgeology,combined with seismic,well logging core,etc, the bed of interest divided into5third-order sequence of beddings in the research. Identify4super sequence boundaries,2third-order sequence boundaries and4four-order sequence boundaries. Through the contrastand division of single well and continuous well sequence, I established isochronalsequence-stratigraphy framework in the research finally, and researched the strata distributingcharacteristics in the sequence framework.Guided by the theory of modern sedimentary learning and combined with depositionalsetting area of interest, we set up the identification mark of the northwest of Beier Depression.Study area identified three types of facies,nine types of sub facies and24types of microfacies.There are three sedimentation systems, such as fan delta, braid river delta and lake facies,developed in region of interest. With the analysis of single well sedimentation micro-faciesand simultaneous well sedimentation micro-facies, it can be learned of spatial distribution ruleof the sedimentation microfacies. With a unit for t third-order sequence and forth-ordersequence, we study the sedimentation system of sequence-stratigraphy framework, and makesure the sedimentary facies characteristic in the study areas during different period. Then wesum up the rule of sedimentary evolution. The sedimentary evolution history of rock magmacan be divided into three periods,such as the fan delta and deep lake in Tongbomiaoformation,fan delta and deeper lake south group in Nantun formation and braid river delta,deeper lake and fan delta in Damoguaihe formation.According to the reservoir characteristics,the northwest of Beier Depression was dividedinto three sets of reservoir cap assemblage. In the study the three sets are all development, inthe vertical direction formed the self-produced self-reservoir, low produce up reservoir andlate-produced ancient reservoir hydrocarbon reservoir characteristics.