The main goal in inorganic geochemistry applied to oil exploration and production is to describe every fact participating in the poroperm evolution oi reservoir formation during burial. Therefore, authigenic and detrital minerals are studied, as well as reservoir waters. Following a relatively short period of mechanical compaction, porosity and permeability characteristics are influenced by cement crystallization and dissolution, and clay material growth. Porosity is dominantly affected by cement type behaviour, while permeability is controlled by the characteristic Variations oi clays. In a classical diagenetic study, the first step is to constrain the temperature time evolution. Diagenetic steps are then reported to the burial curve, and consequences of each phenomena on petrophysical properties are estimated. Clay material is used to determine the absolute age of crystallization, partly to identify the characteristics of crystallization associated waters, and therefore to provide a background for the interpretation of the effects of diagenesis in Exploration-Production. Theoretical considerations are in constant progress, and directly influence critical domaines of interpretation (dating, modellization). So, close relations between interpreter and research groups are most recommended.