Research On Pore Structure And Reservoir Quality Difference Of Chang 7 Oil-bearing Formation In Luohe Oil Field Of Ordos Basin

It is of great significance to go through further research of difference mechanism of tight reservoir quality due to its huge potential oil resources.Basd on different kinds of core data and logging data,this thesis,taking the main reservoir of Chang 7 oil-bearing formation in Luohe Oil Field of south Ordos basin as an example,aims at analyzing the difference mechanism of reservoir quality and summarizing the controlling factors of reservoir quality.Research shows that the pore structure of the study field sandstone can be divided into five types according to the size of pores and throats,and the reservoir quality can be classified into four types.Type I and ? reservoir,with large pores and throats,are the favourable reservoir in the study field.The grain size,composition and the combination of sandstone and mudstone control the type and intensity of diagenesis,which results in the difference of reservoir quality.Fine sandstone with rich plastic components came through strong compaction.Calcite cementation often develops at the top and bottom of sandbodies,which is related to the thickness of mudstone nearby.The best reservoir develops in the middle of channel where the content of rigid components is rich,the grain size is coarse.