Effection of Organic Acids on Sandstone Densification in Shanxi Formation Coal Source Rocks in Ordos Basin

摘要

By means of core observation, conventional thin slice, cathodoluminescence, scanning electron microscopy, and basin simulation, the environment cause of the sandstone micropore in the reservoir were analyzed, the organic fluid and the densification development of the reservoir were studied. The results show that the source rock of coal is dominated by III kerogen. In the process of thermal evolution, a large number of aryl structure and oxygen containing functional groups fall off, III kerogen generates more organic acids than I, II kerogen, it has a stronger transformation effect on quartz sandstone. In the acidic micropore environment, quartz have multiple secondary enlargement and authigenic clay minerals occupied pores, the inorganic minerals (such as feldspar, cuttings) are dissolved. With the evolution of diagenesis, the pores are density, the organic acids in the source rocks of coal are the important reasons for the densification of sandstone.