Published January 2011

Forming of hydrocarbon reservoirs and reasons of preserve of collectable properties in formations on South Caspian depression

K.N.Gahramanov

E.U.Pogorelova

The South Caspian depression is a unique and does not have equivalent in the world by conditions of formations, sedimentary, thickness and speeds, geotectonic history, oil and gas forming deposits, supplies and geological structure of reservoirs. It has been opened and put into industrial exploitation within Absheron archipelago in Caspian Sea Azerbaijan sector high potential oil-gas fields as Azeri-Chirag-Guneshly, Shakh-Deniz, Kapaz, Umid, Zafar-Mashal, Nakhchivan and so on and are connected with Absheron facies. The main supplies of hydrocarbons (more than 70%) in the fields are in the interruption and X horizons of productive series. In the geological structure of these fields took part in Pliocene-Quarternary deposits by thickness 3700-400 meters. There are more than 30 local anticlines on the territory by 37 thousand m2 of South Caspian depression. The main factor is resisting to negative influence of rock pressure to filter capacious properties of layers on the large depths is a layer pressure. The difference between rock and layer pressure, or effective pressure makes worse filter capacious properties with depth. In such kind of conditions hydrocarbon collectors in high level of anticlines by high altitude is relatively high layer pressure because of growing excess pressure.