Research On Sequence Stratigraphy And Depositional Systems Of Shahejie Fml And Dongying Fm3 At Balizhuang Buried Hill Belt In Raoyang Depression

This paper is based on the project,named Integrated study of geology and 3D seismic data pre-stack processing for ngl 1 buried hill in Balizhuang buried hill belt in Jizhong depression,of LandOcean Energy Services Co.,Ltd,.The paper analyses the Shahejie 1 Formation and Dongying 3 Formation of the structural accommodation zone of Balizhuang in Raoyang depression.Based on the theory of high resolution sequence stratigraphy,comprehensively using seismic,drilling/logging data and the cores,the paper studys the research area’s sequence architecture and the temporal and space evolution of the sedimentary systems,predicted the better reservoir zones considering with oil/gas migration and congregation.By well-seismic calibration,the article recognize there sequence boundaries(SB)which are SB1,SB2,SB3.and two maximum flooding surfaces(MFS)which are Fl,F2.The target stratum is into 2 third-order sequences,named as SQ1(correspond-ing to the Shahejie 1 Formation),SQ2(corresponding to the s Dongying 3 Formation).Through 6 correlational profiles,sequence framework in the studied area is established.The base-level rise hemicycle of SQ1 is composed of oil shale formed in shallow-deep lake.The down hemicycle is composed of delta,which is important reservoir.Based on the application of the theory of high-resolution sequence stratigraphy,the article divides the middle-term base-level cycle of the delta to reveal its evolutionary process.The formation is devided into there members which are SQ1Ⅲ,SQ1Ⅱ and SQ1I.SQ2 develops fluvial facies and it is a long-term base-level cycle.The rise hemicycle is named SQ2 Ⅱ and the fall hemicycle is named SQ2I.In the unit of SQ1Ⅲ,SQ1Ⅱ,SQlⅠ,SQ2 Ⅱ and SQ2I,we drawed the plane distribution of sedimentary facies and disclosed the sedimentary characteristic and evolutional process.SQ1Ⅲ formes after a lake flooding and develops front delta controlled by the delta in the northeast.During the period of SQ1Ⅱ,the delta in the northeast progress to the center of the area,and another delta appear in the southwest and deposites delta front.The lake is shrinking in SQ1Ⅱ,the scale of both the two deltas reach the biggest.The delta plain occurs in the northwest.The lake retreats from the study area in the deposition period of SQ2 and meandering stream widely develo-ped.SQ2I has more channel sand than SQ2II.Under the control of sequence framework and sedimentory study,we use inversion technology to predict the distribution of reservoir and find out that SQ2I and SQ1Ⅰ are the best.After analyzing reservoir forming conditions and estabolishing its trap mode,the paper evaluates the favorable prospects,and proposes that SQ1Ⅱ and SQ1Ⅰ is the mainly potential layer and structure-lithologic hydrocarbon reservoir has been thought of a focal point of exploration.