Porosity evolution in sandstone reservoirs / Развитие пористости в песчаниковых коллекторах

Sandstone reservoirs are the host for almost 60 percent of the world’s oil and gas reserves, and an understanding of the factors that determine the location and distribution of reservoir-quality sandstones is essential for any successful exploration and exploitation program.
Until fairly recently, it was assumed that correct prediction of the penetration depth, along with the applicable sedimentologic model, would provide all the necessary information on the reservoir potential of a sandstone. The porosity of a sandstone is the capacity of the sandstone to store fluids. Permeability is the ability of the sandstone to transmit fluids. Porosity was thought to have been destroyed at a consistent rate with depth and no consideration was given to the possibility of porosity enhancement with depth. However, it is now apparent that the pore systems of sandstones undergo a complex reorganization during burial in response to a changing physical and chemical environment. This reorganization may result in the development of secondary porosity from both porosity redistribution and porosity enhancement, as well as in the destruction of both primary and secondary porosity. The general term applied to the post-depositional processes effecting these changes in the rocks and their pore systems is diagenesis. <...>