Study on Physicochemical Characteristics of Shale Oil Reservoir Rocks in the 3rd Sub-member of the Triassic Chang 7 Member in Southern Ordos Basin

摘要

Shale oil is a kind of unconventional oil resource with great potential.China is rich in shale oil resources.There is a good shale oil reservoir in the 3 rd sub-member of The Triassic Chang 7 member in Southern Ordos Basin,but at present there is insufficient understanding of the physical and chemical characteristics of the rock.This results in frequent instability of the well wall during the drilling process,which affects the drilling cycle and the length of the horizontal segment.To this end,the research on Bl well,which is a key exploration well in the Southern Ordos Basin,is carried out in the experimental study of the core system observation description,structural analysis,and hydration degree test.The results show that the upper part of the reservoir is mainly black stratiform shale,with a large number of horizontal cracks,large sand sandwich density,low clay mineral content,and basically no hydration capacity The lower part is tuff,which has a certain degree of horizontal cracks and contains some structural seams.The content of clay minerals is high and it has certain hydration ability.The differences in the structural characteristics,hydration and salinity of the two types of reservoirs were clarified,which provided a basis for the design of subsequent anti-collapse drilling fluids,and provided a basis for safe and efficient drilling in the 3r sub-member of The Triassic Chang 7 member in Southern Ordos Basin.