The Tarim Basin is a typical superimposed basin in which there have occurred mul-tiphase adjustment and destruction of the reservoirs. The widely distributed asphaltic sandstones of the Silurian are the very product a...The Tarim Basin is a typical superimposed basin in which there have occurred mul-tiphase adjustment and destruction of the reservoirs. The widely distributed asphaltic sandstones of the Silurian are the very product after destruction of the reservoirs. Studies show that the Silu-rian asphaltic sandstones distributed in both the middle and western parts on the basin are con-trolled chiefly by the Caledonian oil source area and by the Tazhong, Tabei and Bachu uplifts, whereas the distribution of the asphaltic sandstones on local structural belts is controlled by the reservoirs sedimentary system. Vertically, most of the asphaltic sandstones are under the re-gional caprock of red mudstones and the upper sandstone section of compact lithology. Due to the difference of hydrocarbon destruction in the early stage and the influence of hydrocarbon recharge in the late stage, the asphaltic sandstones and oil-bearing sandstones in the Tazhong area can be vertically divided into the upper and lower sections and they have an interactive distribution relationship as well. Asphaltic sandstones exist not only in intergranular pores but also inside the grains of sand and between the crevices, proving the destruction of early reser-voirs due to uplifting. The existence of asphaltic sandstones over a large area reveals that the large-scale migration and accumulation and the subsequent destruction of hydrocarbons in the Craton area. The destruction caused a loss of the reserve resources of the Palaeozoic amount-ing to nearly 13.3 billion tons. Asphaltic sandstones formed after the destruction of oil and gas may serve as an effective caprock which is beneficial to accumulation of hydrocarbons and for-mation of the pool sealed by asphaltic sandstones in the later stage. The destruction of the early Silurian hydrocarbons depends on the stratigraphic burial depth. The deep part under the north-ern slope of Tazhong is an area favorable to search of undestroyed Silurian oil reservoirs.展开更多
文摘The Tarim Basin is a typical superimposed basin in which there have occurred mul-tiphase adjustment and destruction of the reservoirs. The widely distributed asphaltic sandstones of the Silurian are the very product after destruction of the reservoirs. Studies show that the Silu-rian asphaltic sandstones distributed in both the middle and western parts on the basin are con-trolled chiefly by the Caledonian oil source area and by the Tazhong, Tabei and Bachu uplifts, whereas the distribution of the asphaltic sandstones on local structural belts is controlled by the reservoirs sedimentary system. Vertically, most of the asphaltic sandstones are under the re-gional caprock of red mudstones and the upper sandstone section of compact lithology. Due to the difference of hydrocarbon destruction in the early stage and the influence of hydrocarbon recharge in the late stage, the asphaltic sandstones and oil-bearing sandstones in the Tazhong area can be vertically divided into the upper and lower sections and they have an interactive distribution relationship as well. Asphaltic sandstones exist not only in intergranular pores but also inside the grains of sand and between the crevices, proving the destruction of early reser-voirs due to uplifting. The existence of asphaltic sandstones over a large area reveals that the large-scale migration and accumulation and the subsequent destruction of hydrocarbons in the Craton area. The destruction caused a loss of the reserve resources of the Palaeozoic amount-ing to nearly 13.3 billion tons. Asphaltic sandstones formed after the destruction of oil and gas may serve as an effective caprock which is beneficial to accumulation of hydrocarbons and for-mation of the pool sealed by asphaltic sandstones in the later stage. The destruction of the early Silurian hydrocarbons depends on the stratigraphic burial depth. The deep part under the north-ern slope of Tazhong is an area favorable to search of undestroyed Silurian oil reservoirs.
