The Sand Bodies Distribution Characteristics Of Upper Paleozoic In South Sulige

The area at the south of Sulige gas field rich in natural gas resources and has great protential for exploration.The exploration area is about 52000km².But the formation reservoir is heterogeneous and it is difficult to predict high permeability reservoirs.Therefore,we make a detailed comparison of the upper Paleozoic Sandstone in Sulige area,this is very important to define and divide the skeleton sand and find out the law of the distribution of the sand body.This study is based on the sedimentary sand body in South of Jiangsu area,Ordos Basin,based on the detailed observation and description of the core,well classification and the study of the characteristics of the time and space evolution of the sedimentary system,the distribution law of the reservoir and its main controlling factors are analyzed.Finally,the distribution of sand body is predicted.The main objectives are the following two points:1.According to the distribution and contrast of the framework sand body,on the basis of the existing stratigraphic division scheme,the fine division and correlation of the stratigraphic profile.2.Through the comparison of the upper and lower layers of the framework sand body in the upper Paleozoic,the distribution law of the sand bodies and the vertical superimposition relationship are studied.During the study period,the high resolution sequence stratigraphic division of the study area was completed by the analysis of the logging and seismic data.The sequence of the study area is established,S₁1?MSC3??S₁2?MSC2??S₁3?MSC1?and upper H₈1?MSC7??upper H₈2?MSC6??lower H₈1?MSC5??lower H₈2?MSC4?.In the vertical direction,the sand bodies of different genetic types show different structural forms.In the vertical direction,sand body performance of different genetic types for different structures,the single sand body in the section mainly on flat convex and flat convex type 2 types;in the plane,there are lenticular,banded,lobate,pedately 4 kinds of sand distribution form.Favorable reservoir sand bodies mainly developed in the northeastern part of the study area during S₁2 depositional period and lower H₈2 depositional period,the distribution of the form in the plane showing a solitary or striped.The main reservoir sand bodies are the underwater distributary channel sand bodies during the S₁2 depositional period,the main reservoir sand bodies are braided shunt river and sand beach sandbody in the H₈2 depositional period.