| The gravity flow in lower third sub-member of Shahejie Formation in Dongying Sag is the main lithologic reservoir in the east of Dongying sag.Predecessors have done a lot of work on the structure,source rocks and sequence of Sha3 lower member Formation in Dongying Depression and obtained a lot of research results.However,there is a lack of systematic research on the deep-water sedimentation system in the eastern part of the Dongying Depression.It is imperative to strengthen the study of the genesis and evolution of sedimentary sand bodies in the deep water below the Sha3 lower member in the eastern Dongying sag.The model of sedimentary sand body of gravity flow in the deep-water basin of the eastern Dongying sag,the classification of high precision sequence and the type of gravity flow are established,and the understanding of the theory of deep-water gravity flow is strengthened.Further guidance for the exploration and development of deep-water lithologic reservoirs in the Jiyang Depression and the discovery of new lithologic reservoirs.The study area stratum of the third member of the Shahejie formation is mainly in a deep-semi-deep water sedimentary environment.The division and identification of sequence stratigraphy divide the unified identification of the Sha3 lower member formation into a set of three-level sequence.Two system domains of lake invasion and lake retreat areidentified.And study area stratum be divided into seven parasequence groups through the methods of ?logR.And its deep-water sedimentary characteristics can be well identified and divided in the whole area.It was found that the deep-semi-deep water sedimentary sand bodies in the interior of the stduy area are mainly distributed on the northern steep slope and the lower part of the southern gentle slope,and on the eastern slope.The belt is also developed,and the sedimentary center in the study area is mainly located near the central depression in the depression.Through the sectioning process of the well section,it was found that the large-scale gravity flow area in the deep water area of the study area mainly appeared in the basin channel zone,showing a striped distribution.According to its channel instructions,it is known that its source is mainly from Chenjiazhuang and Guangrao uplift in the north and south of Dongying sag,and Qingtuozi uplift also has inputed.In terms of basin evolution,the paleoclimate of thefourth of shahejiememberis favorable for the weathering and denudation ofthe provenanceand provides favorable source conditions for Sha3 lower member.According to the sedimentary faciesidentification marks of the third member of the Shahejie Formation in the project area,the accumulated deep water-semi-deep water and turbidite fans identified in the study area were identified.It can be observed that the sediment in the mud and shale,which mainly shows dark colored shale,is mixed with gravel in the drilling data.At the same time,according to gravity flow sedimentary rock classification and identification,it is identified that there are four types of gravity flow sedimentary rocks in the study area: sliding rock,slumping sedimentary rock,detrital flow sedimentary rock,and turbidite sedimentary rock.In terms of gravity flow trigger mechanism in the study area,based on research data and research data analysis,this study mainly concludes that the triggering mechanism of gravity flow in the study area mainly consists of the fluctuation of Lake plane,the wave erosion of lake water,and the instability of the formation caused by the tectonic activity. |
PDF Full Text Request