Kheirov M.B.

During the formation of oil and gas deposits, besides geological-tectonic and other different factors, an important role is also played by the hermeticity of seals. Preservation of the hydrocarbons (HC) accumulated in reservoirs, depends on their quality. It is quite natural that the investigation of seals and the extent of their hermeticity is of theoretical and practical importance, as the change of their fluid-tight results in the destruction of the deposits and in their reformation. Different lithological types of rocks can play a role of seals and reservoirs. The paper, mainly, considers the results of investigations of clayey seals linked with the HC deposits in most of the deposits in Azerbaijan. A special attention is paid to the different factors making an impact on the fluid-tight of the rocks lithological-mineralogical, lithogenetic, sedimentological, paleogeographical, physical-chemical, thermobaric etc.

A special attention is also paid to the impact of the time factor and sedimentation rate in the basin.