The Plays’ Characteristics Of Petroliferous Basins In Central Aisa

The Central Asia’s Oil/Gas Basins are located in the middle and southern segment of Eurasia Land, Middle East Giant fields to the south and Volga-Ural Giant fields to the north, which holding big Oil/Gas potential. To analysis the Plays’ Characteristics is a good reference for China’s oversea energy exploration and development.There are total 16 basins in Central Asia, however,9 basins of which are chosen to be the analysis object, as the 9 basins are the only basins containing oil/gas. Some of these 9 basins were Paleozoic rift margin and back arc remnant basin, during Mesozoic they are developed as back arc stretch and subsidence basins, and during Cenozoic developed into foreland basin. These 9 basins have widely developed various types of plays, but it is still in immature stage of the comprehensive analysis for the plays’ characteristics in Central Asia Oil/Gas Basins. By utilizing theory and methods of petroleum system and play, Gathering the latest Papers and Data, Based on the previous people’s points, major play strata and types are concluded by the plays’ reserve statistics. Timely the types of source, reservoir and seal as well as traps are divided, horizontally the distributions of source, reservoir and seal are marked. The plays’ units matching relations was discussed by combining the plays’ units into regional structures and sediments background.As based in different tectonic and sedimentary background,9 basins have various type of source, reservoir, seal and types of oil/gas as well as different reserves. Tectonically, it can be divided into 3 segments, the northern segment, the middle segment and the southern segment. The northern segment is located in Eurasia margin and southwest segment of Kazakhstan, which is mainly developing Paleozoic Plays’ basins; the middle segment is Turan block which is mainly developing Mesozoic Plays’ basins; the south segment located in and near Tethys folds zone which is mainly developing Cenozoic Plays’ Basins. There are 3 west-east sea transgressions in sedimentary history:late Devonian-early Carboniferous; middle Jurassic-late Jurassic; late Cretaceous-Paleogene. From the point of source time, concentrating on upper Devonian-lower Carboniferous Carbonates and shale; Mesozoic and Cenozoic coal, marl and shale as well as carbonates are the major sources.The migration paths are mainly along where evaporite is poorly sealing and unconformity, and then fault. The migration directions are fault related structurally highs and good quality reservoirs. The types of plays are mainly carbonate and clastic related Stratigraphic-Structural during late Paleozoic, Jurassic and Cretaceous time, moreover developed into Structural related plays during Cenozoic. The Plays Characteristics are divided into 3 types:1) structures related plays; 2) non-structures (Lithology, formation and pinch-out) related plays; 3) stratigraphic-structure related plays.