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结合川东地区地质条件和沉积演化史,对普光5井等4口井中—古生界岩心(岩屑)样品的伊利石结晶度及热史进行了系统研究。结果表明,伊利石结晶度是海相高演化层系成熟度的重要指标。在川东地区,中生代陆相地层的伊利石结晶度多大于0.42°(Δ2θ),镜质体或沥青反射率小于3%,地层尚处于晚成岩后期阶段;中、古生代海相地层伊利石结晶度多为0.42~0.25°(Δ2)θ,镜质体或沥青反射率为3%~6.5%,地层处于极低变质阶段。川东北地区伊利石结晶度与晚期包裹体均一温度及由镜质体反射率推算的古地温有较好的线性关系,当伊利石结晶度为0.42°(Δ2θ)时,晚期包裹体均一温度及由镜质体反射率推算的古地温约为180℃,地层已进入有机质过成熟和晚成岩后期阶段。
Based on the geological conditions in East Sichuan and the evolution of sedimentary history, the illite crystallinity and thermal history of Mesozoic-Cenozoic cores (cuttings) from 4 wells in Puguang 5 well were systematically studied. The results show that the illite crystallinity is an important indicator of the maturity of marine high-evolution strata. In the eastern Sichuan area, the illite crystallinity of the Mesozoic continental strata was more than 0.42 ° (Δ2θ) and the vitrinite or bitumen reflectivity was less than 3%. The strata were still in the late late diagenetic stage. The Mesozoic and Paleozoic marine strata were illite The degrees are mostly 0.42 ~ 0.25 ° (Δ2) θ, vitrinite or bitumen reflectivity is 3% ~ 6.5%, and the strata are in the extremely low metamorphism stage. The crystallinity of illite in the northeastern Sichuan has a good linear relationship with the homogenization temperature of late inclusions and the paleogeothermal predicted by the vitrinite reflectance. When the crystallinity of illite is 0.42 ° (Δ2θ), the homogenization temperature of late inclusions and The paleotemperature estimated by the vitrinite reflectance is about 180 ℃, and the strata have entered the late stage of organic maturity and late diagenesis.