Controlling Effect Of Chang 2 Reservoir Difference On Oil Distribution In G Area Of Qingpingchuan Oilfield

The Chang 2 oil layer group in the G area of Qingpingchuan Oilfield has abundant oil resources,but the investigation and research on the reservoir geology are not detailed enough.This paper is mainly to carry out a series of petroleum geology research on the heterogeneity of the reservoir and the control of oil distribution in the process of development of Chang 2 oil layer in the study area.Through the interpretation of drilling,logging and logging data,core description and sample analysis in the study area,sub-layers are divided into more than 300wells in the study area according to the rhythm of sedimentary cycles and the identification of sub-layer marker layers.The structural background,stratigraphic development characteristics and oil and gas geological conditions of the study area are discussed in combination.On this basis,the reservoir characteristics and reservoir heterogeneity characteristics of tight sandstone are analyzed.At the same time,based on various analysis and test results and statistical data,the heterogeneity of the reservoir is combined with the distribution law of the Chang 2 oil layer in the study area to analyze the correlation between oil and gas enrichment and the reservoir.The results show that the sandstone of Chang 2 oil layer group in the study area is mainly composed of feldspar,with a small amount of quartz and debris.Most of the pores in the reservoir are primary intergranular pores,followed by dissolution pores.Oil and gas are mainly distributed in three small oil layers,Chang 2₁³,Chang 2₂¹ and Chang 2₂².The Chang 2oil layer is a low porosity and ultra-low permeability reservoir.The porosity,permeability and oil saturation are all distributed in strips from northeast to southwest.The diagenesis of the reservoir is relatively strong,and there are four kinds of effects that have the greatest influence on the physical properties and pore structure of the reservoir,namely compaction,cementation,metasomatism and dissolution.The heterogeneity of the reservoir is oil-controlling and has a certain control on oil enrichment.