Hydrocarbon system of the South Caspian Depression

Abstract

Actuality. The hydrocarbon generation sources in the South Caspian Basin (SCB) are located at the depth of nine or more kilometers, where the organic-rich Maikop sediments occur. The main oil-and-gas fields here are found in reservoirs of the Productive Strata (Lower Pliocene), bedding at a depth of one or more kilometers. At the same time, the significant role at the process of hydrocarbons migration from the source of their generation to the reservoirs belongs to the tectonic faults (fractures). However, the results of the research according to the latest seismic data carried out in recent years are indicated the unavailability of the tectonic faults in the SCB, which connected the hydrocarbon generation sources with the reservoirs in the Productive Strata. Target. The determination of the geological elements at the studied area that contributed the role of the hydrocarbon migration channels and connected generation source with reservoirs in the Productive Strata. Objects. The hydrocarbon generation source, hydrocarbon migration channel, tectonic faults and fractures, Productive Strata reservoirs, eruptive channels of the mud volcanoes. Approach. The collaboration interpretation results of the deep drilling and the seismic data by using the common depth point method. Results. Based on the structural interpretation results of the seismic data with high-resolution parameters, are indicated the lack of the tectonic faults which connecting the hydrocarbon generation source with reservoirs of the Productive Strata in the SCB. In addition, the hydrocarbons that generated in the Maikop sediments are transported to the Productive Strata reservoirs by the eruptive channels of mud volcanoes. The opinion that the process of hydrocarbon generation in the Maikop clay deposits continues to the present time and the mud volcanoes eruptive channels provide feeding of the deposits with the continuous supply of oil-and-gas was expressed. Such kind of mechanism allows to classify the deposits, that more than a century under developed in the South Caspian Depression and which located at the zone of mud volcanomaturity, to the category of replenished.