塔里木盆地志留系沥青砂岩的形成期次及演化

Hydrocarbon Filling Ages and Evolution of the Silurian Asphalt Sandstones in Tarim Basin

从志留纪起 ,塔里木盆地下古生界烃源岩经历了三期生、排烃。下古生界源岩的生烃期和志留系的圈闭形成期控制了志留系沥青砂岩的形成期次及演化。志留系早期沥青砂岩形成后 ,经历了后期多次的构造沉积事件和三次烃类注入、混染 ,改变了志留系古油藏沥青形成时的原始产状。志留系沥青砂岩的三次注入分别是 :第一次是晚加里东注入期 ;第二次是晚海西—印支注入期 ;第三次是燕山—喜山注入期。志留系砂岩中沥青、稠油或其它油气显示是这三期作用的综合结果。

From the Silurian period, there have been three times of hydrocarbon generation and expulsion for the lower Paleozoic source rocks in Tarim basin, and the hydrocarbon generation ages of the lower Paleozoic and the trap formation ages of the Silurian together controlled the filling ages and evolution of the Silurian asphalt sandstones. After being formed in early of the Silurian, the Silurian asphalt sandstones underwent several sedimentary and tectonic events and three times of hydrocarbon filling and mixing, and these made the original distribution and occurrence of asphalt in the Silurian paleo-oil reservoirs complicated. The three times of hydrocarbon filling to the Silurian asphalt sandstones are as follows: the first time of filling took place in the late Caledonian, the second from the late Hercynian to Indosinian, and the third from the Yanshanian to Himalayan. Therefore, the mixture of asphalt, heavy oil, and normal oil and gas shows that the Silurian asphalt sandstones are the result of the three times of hydrocarbon filling.