Carboniferous sedimentary facies of Kolzhan area in Pre-Caspian Basin

Kolzhan area is located in Biykzhol relief, southeast of Astrakhan-Aktyubinsk uplift in PreCaspian Basin, and Kungurian salt of Lower Permian is developed widely here. The whole profile is divided into 2 hydrocarbon-bearing series by salt sediments, one is dominated by clastic rocks and another is dominated by carbonate rocks. Carboniferous formation is one of the main hydrocarbon-bearing formations beneath the salt sediments. According to the analysis of cuttings well K as well as the logging data, Carboniferous sedimentary characteristics are analyzed and sedimentary facies are classified and described. Three types of sedimentary facies are developed in Carboniferous formation of well K, including deep-water turbidite fan, slope and platform facies. Deep-water turbidite fan is further divided into inner, middle and outer fan, and platform facies is divided into interbank sag and platform shoal. Using drilling results of well K and regional data, early and late Carboniferous sedimentary facies distribution is predicted initially in Kolzhan area.