| The physical properties of the reservoir largely depends on the characteristics of reservoir rocks, the structural geological background of the petroliferous basins, hydrodynamic conditions, and water-rock interactions characteristics and so on. The water-rock interaction involves in the entire reservoir diagenetic evolution and the whole process of oil and gas from the formation, migration and accumulation, and it also associates with the distribution oil and gas. In this paper, we use some comprehensive methods to analyze organic matter content of sandstone, the main element abundance and the mineral composition features of the sandstone reservoirs, as well as the water-rock interaction in it. The results are summarized below.The reservoir rocks in the Minhe Basin are mainly feldspar and quartz sandstone, including a few feldspar sandstones and lithic sandstones. The secondary porosity types of the sandstones are mainly dissolution pores between grains, intragranular dissolution pores, intergranular authigenic porosity and cracks. Organic carbon experimental data show that the sandstone of oil leaks are 1.00%-1.61%, the mudstone are 0.17%-0.13%, non-oil-bearing sandstone is 0.04%. XRD data show that the minerals of the sandstones are mainly quartz, feldspar, calcite and a small amount of clay minerals.The emplacement of oil in the reservoir made the pH value of the reservoir lower, leading to some dissolution and deposition. As a reducing substance, crude oil and some oxidative minerals can occur redox reaction and produce low-cost state salt, CO2, H2O, etc. And it also inhibits the metasomatism.
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