Research On Sedimentary Microfacies Of Wenkuang Sand Group In The 2nd Member Of The Shahejie Formation In Xin 15 And Peripheral Blocks Of Dong Xin Oilfield

Dongxin oilfield is the source region of Shengli Oilfield,Xin 15 fault block is an important oil production block in Dongxin oilfield,which belongs to high water cut complex fault-block Oilfield.However,the division and correlation of layers in this area still need to be carried out,the temporal and spatial distribution of the sedimentary microfacies and the distribution rules of the related reservoir sands are still to be revealed.Based on the theory of seismic stratigraphy?logging geology and sedimentology,this paper systematically studied the sedimentary microfacies of the Es2 formation of Wenkuang sands group in Xin15 and peripheral blocks of Dongxin oilfield that combines with regional structure and sedimentary background.It established a regional comparison lattice,and a systemic analysis was carried out on the microfacies distribution and evolution of the sedimentary microfacies in this study area,then rebuilt sedimentary model of the Es2 formation of Wenkuang sands group in Dongxin area.The main achievements are as follows:This paper carries out the thin layer division and contrast for the Es2 Formation of Wenkuang sands Group,which is divided into 22 small layers,It also establishes the contrast framework of the small layer of Xin 15 and surrounding areasAccording to lithology?structure?fossils?sedimentary facies and sequence structure characteristics of Xin 15 and surrounding areas,we think that delta front deposits developed in the littoral shallow lake background in the Es2 formation of Wenkuang sands group and further identified the main sedimentary microfacies including the underwater distributary channels,mouth bar,distal bar,underwater shunt bay.Summarized the comprehensive characteristics of each sedimentary microfacies type,and established the identification mark and the rock-electrical correspondence of the main sedimentary microfacies of the Es2 formation of Wenkuang sands group in Xin15 and peripheral blocks of Dongxin oilfieldUsing the point-line-plane idea,analyzed the temporal and spatial distribution of the sedimentary facies in the Es2 formation of Wenkuang sands group and the characteristics of vertical evolution and plane distribution of the sedimentary system are concluded.It summarized 5 kinds of boundary mark of delta front mouth bar sand body and the peripheral area,proposed two types of sand body splicing by identifying boundary of sand body and distribution of single sand body morphology.One kind is single distributary channel and estuary dam Mosaic style.Another kind is splicing patterns of a single estuary dam.Among them,the latter can further identify the connection between the dam body and the dam body of the estuary dam,dam body-dam edge-dam body style and estuary dam-underwater distributary bay-estuary dam splicing combination style,etc.This research improved the accuracy of the small layer division,enhanced the accuracy of the study of sedimentary microfacies space time,provided a good basis for oil and gas potential tapping,and the sand body splicing pattern will play a very good role in guiding the oil and gas exploration in the area...