Recent advances on microscopic pore characteristics of low permeability sandstone reservoirs

Understanding oil and gas production from low-permeability sandstones requires an understanding of the porosity. This paper reviews the analysis of data from hundreds of cores’ microscopic pore characteristics of low-permeability sandstone reservoirs from Chang 6 reservoir of Ji-yuan oilfield in ordos basin. And this paper is to embody the methods used in the study of low permeable sandstone reservoir in recent years and the results reflected in it. For example, by analyzing the rock of Chang 6 reservoirs, it can be seen that the rock of Chang 6 reservoirs is mostly developed by Feldspar Sandstone, its internal pore types are diverse, the pore size is mainly small pore type, the second is fine pore, and has continuous spectral distribution, and the distribution is single peak shape. Different methods have been used to study low-permeability sandstones, including scanning electron microscope, casting thin plate, physical test means, high-pressure mercury, constant velocity mercury, NMR experiments. The results show that the pore-throat combination types of reservoir are mainly small pore-micro-larynx. The main type of reservoir throat is mainly flaky throat. The extremely strong heterogeneity in the layer is the key to the efficiency and effect of water flooding. Therefore, the exploration and development of low permeable sandstone reservoirs can be guided by the analysis of relevant parameters