准噶尔盆地陆东-五彩湾石炭系烃源岩特征及生烃动力学研究

Characteristics and hydrocarbon generation kinetics of the Carboniferous source rocks in the Ludong-Wucaiwan area, the Junggar Basin

准噶尔盆地陆东-五彩湾地区石炭系具有良好的勘探前景，该地区石炭系烃源岩有机质丰度较高，成熟度范围宽，主要处于成熟-高成熟演化阶段，主要由Ⅲ型有机质组成。在对烃源岩样品进行常规评价的基础上，用开放体系进行了热解实验和动力学模拟，对陆东-五彩湾地区的生烃特征进行了研究，尝试了高成熟烃源岩生烃过程研究及Ⅲ型干酪根液态烃排烃时间的估计，并对石炭系地层产烃率进行了计算。结果显示，陆东-五彩湾地区石炭系最早在二叠纪（距今264 Ma左右）开始生烃，后期由于地层抬升，在古近纪早期（距今61 Ma左右）结束生烃。下石炭统产烃率大，液态烃排出时间估计在距今232~196 Ma之间；上石炭统产烃率较小，液态烃排出时间估计在距今196~178 Ma 之间，但天然气生成相对较晚，有利于天然气的保存。天然气可能主要来源于上石炭统烃源岩。

There are good exploration prospects of petroleum from the Carboniferous source rocks in the Ludong-Wucaiwan area, the Junggar Basin. Routine analysis was carried out to evaluate the Carboniferous source rock samples collected from the Ludong-Wucaiwan area. The results show that the Carboniferous source rocks have high abundance, wide maturity range from mature to high mature, and the source rock have organic matter with Type Ⅲ kerogen. Further kinetic study was performed by using open system pyrolysis to elucidate the characteristics of the hydrocarbon generation. The tries on the hydrocarbon generation process of the matured source rocks and the estimation of liquid hydrocarbon expulsion from type Ⅲ kerogen are conducted, and hydrocarbon yield of Carboniferous hydrocarbon source rocks was calculated. The results show that the hydrocarbon-generation started in the Permian （about 264 Ma）, and ended in the early Paleogene （about 61 Ma）, since the strata uplifted. The Lower Carboniferous hydrocarbon source rocks, which have large hydrocarbon yield, expulsed the liquid hydrocarbon from 232 Ma to 196 Ma. The Upper Carboniferous hydrocarbon source rocks, which have small hydrocarbon yield, expulsed the liquid hydrocarbon from 196 Ma to 178 Ma. However, the＆nbsp;natural gas generated relatively late from the Upper Carboniferous, which is beneficial to be preserved. The natural gas probably derived from the Upper Carboniferous source rocks.