The Sedimentary System And The Favorable Sandbody Distribution Of The Lower Part Of 4th Member Of Shahejie Fomation To The 1st Member Of Kongdian Fomation In The Northern Slope Of Yihezhuang Uplift

Yihezhuang uplift is located in the northeast Jiyang Depression,and surrounded by Chezhen Sag,Zhanhua Sag.In recent years,four oilfields —Yidong,Yibei,Yihezhuang and Taiping have been verified in this surrounding area.However no reserves is reported in the red-bed of the research area.The exploration degree in this zone is extremely low that further study of oil and gas exploration is needed.And in the red-bed deposition period of Jiyang Depression,People have made good achievements in oil and gas exploration of red-bed in southern slope of Dongying Sag and the southern slope of Zhanhua Sag where there were similar sedimentary environment to the study area.Therefore,the red-bed in the reaserch area for oil and gas exploration has fine prospects.This paper constructs high-resolution stratigraphy framework of the 4th Member of Shahejie Formation by the investigation of sequence stratigraphy.And on this basis,this paper have done research on sedimentary system and favorable sandbody.Because the lack of rocket radioactivity and the characters of well-logging,as well as the drilling data and paleontologic data,we accomplished our research work almost through the seismic data.Using principles and methods of seismic sedimentology,this paper tried to improve the longitudinal resolution of seismic data and construct the sequence stratigraphic framework.Meanwhile by 90 ° phase transformation technique,spectral decomposition technique and seismic attributes analytic technique,etc.,the research on sedimentary system and favorable sand area has been accomplished.By integrated analyses of core,logging and 3D seismic data,this paper proved that there is no Kongdian Formation deposits in the research area.The 4th Member of Shahejie Formation overlaps on the buried hills of Mesozoic Eras.Because the research area is in the basin margin,the lake water is shallow.There are some red sediment of the Upper Submember of the Fourth Member of the Shahejie Formation in local area.The third-order sequences in the research area can be classified into 2 sequences based on the distinguishment of crucial interface,as well as 3 fourth order sequences,and 8 fifth order sequences.In the sequence stratigraphic framework,this paper calibrated strata slices of seismic attributes on the base of ancient landform and ancient climate research.Therefore,it reachesd the conclusion that region of interest mainly developed shallow delt and alluvial fan facies.With the oil testing results,dessert attribute seismic waveform classification results and evolution law of sedimentary facies,this paper deduced the range of the favorable sandbody.The favorable sandbody mainly distributed in the middle sublacustrine fan and the fan marginal subfacies,the delta plain and the delta front of shallow deltas.Most of the well logging curve shape is box-shaped or bell-shaped of Which the test oil conclusion is oil reservoir.Based on the analysis of landform,this paper identifies that the favorable sandbody distribution is related to distributor canals in the eastern of region of interest.