Research On Sedimentary Characters Of Fluvial Facies Of The Lower Member Of Guantao Formation In Sanhecun Sub-sag

The shallow layer of the Sanhecun Oilfield is a new section of Shengli Oilfield exploration.In recent years,the lithologic reservoir has been drilled in the lower part of the study area.The sedimentary characteristics are not consistent with the extensive braided river sandbody.Therefore,it is necessary to study the sedimentary characteristics of the lower part of the study area,so as to provide the basis for the next exploration and deployment of the lower part of the area and even the whole coastal area.Based on the logging data and the theory of sedimentary and sequence stratigraphy,this paper is based on the lithologic marker layer,wavelet transform,sedimentary cycle characteristics and well-rock combined method,The lower section of the museum is divided into five sand group,24 small layers,to build the region fine stratigraphic framework.Based on the drilling data of more than 60 wells in Sanhecun,the types of sedimentary microfacies were identified by means of particle size analysis,logging,logging and seismic interpretation.The distribution characteristics of sand bodies were analyzed.Spatio-temporal Distribution of Sedimentary Microfacies.According to the regional tectonic characteristics,the paleo-water body,the seismic facies and the logging data determine the source direction of the lower section of the Sanhecun area.The lower strata of the Sanhecun sub-sag is a far-source braided river sedimentary system,and the sand body is northwest.The source is mainly from the southeast direction.The lower reaches of the Sanhecun sub-sag are mainly developed by river sediments,floodplains,abandoned rivers,and duct fan deposits.The lower section of the lower part of the lower reaches of the braided river is smaller,the flood plain microfacies and the abandoned river are gradually developed.Using the results of logging curve porosity data and stratigraphic division,the compaction correction of sandstone and mudstone is carried out to restore the thickness of the formation and the thickness of sand and shale.The results show that the thickness of the strata and the sand content are larger in the initial stage of the sediments,and the scale of the river is small in the early stage of development,but the flow of single sandbody is frequent,the majority of the connectivity in the transverse direction is poor,stacked.The thickness of the sand body in the lower reaches of the lower part of the reservoir is weakened,the channel migration is weakened,the connectivity of the sand body is deteriorated,and the mud layer is sandwiched between the sand bodies.According to the distribution characteristics of the sand body in the vertical and flat surface,combined with the regional tectonic background,the source system and the depositional datum facies,it is found that the sedimentary facies and sedimentary datum factors are obvious.The village is located in the northern part of Chenjiazhuang,raised by the strong role of blocking,the relative lack of supply of material,sediment mud content is higher.In the early stage of the deposition of the pavilion,the space can be small,the lateral migration of the river is strong,and the sandbody is more serious.The sandbody is widely distributed and the connectivity is better.The lower reaches of the lower reaches of the reservoir can accommodate the larger space,the river migration effect is obviously weakened,sand body between the mud layer,connectivity weakened.In addition,the main river of the study area flows from the southeast to the northwest,near the main stream to the nearby,the sand body deposition thickness is large,the muddy content is less;the river edge,the sand body is thin,the mudstone quantity increases.The presence of Chenjiazhuang raised this difference.