Preliminary Study On Transformation Of Fluids To Solids In Petroliferous Basins

In this dissertation, the author analyzes the products——quartz, ferrocalcite and solid bitumen, from transformation of fluids to solids, and their impact on pore structure, porosity and permeability of sandstone, by core material, thin section and core properties, based on regional geology, burial history and basin fluid history. The conclusions are as follows:(1) In Upper Paleozoic of Ordos Basin, quartz, ferrocalcite and solid bitumen are general solid products of transformation from fluids. Quartz, from the transformation of fluids to solids, often fills throats and the edges of intergranular pores of sandstone. Ferrocalcite, as well as solid bitumen could completely fill large intergranular pores and throats of sandstone.(2) From the distribution, in sandstone pores, of quartz, ferrocalcite and solid bitumen, we can infer that in Upper Paleozoic of Ordos Basin, there are conditions for the forming of fluid with high SiO2 concentration, the mixing of fluids containing Fe2+, Ca2+and CO32-, the supplement of Fe2+, Ca2+ and CO32- to fluid, and the producing and migrating of dissoluble bitumen, but no conditions for the supplement of SiO2 to fluid.(3) The content of quartz, from the transformation of fluids to solids, has no corresponding relationship with porosity and permeability of sandstone. When the content of quartz is high, the porosity and permeability of sandstone may still high. Ferrocalcite, as well as solid bitumen, has negative correlation with porosity and permeability of svandstone. The porosity and permeability of sandstone both fall down abruptly when one of the contents of ferrocalcite and solid bitumen is high.