辽中凹陷古近系烃源岩生烃模拟

Hydrocarbon generating simulation of Paleogene source rocks in Liaozhong sag

在统计分析辽中凹陷多套烃源岩地球化学数据的基础上,计算地层剥蚀厚度,选择多种生烃模拟参数,利用盆地模拟软件对辽中凹陷古近系沙三段、沙一段、东下段烃源岩进行生烃模拟,分析辽中凹陷古近系多套烃源岩的生烃现象。研究结果表明:辽中凹陷沙一段、东三段烃源岩都具有两期生烃现象,并且位于盆地沉降中心的烃源岩生烃速率比斜坡带上烃源岩生烃速率高。沙三段烃源岩由于埋藏深度深、沉积厚度大、有机质丰度高等因素的影响虽然生烃期次只有一次但生烃效果较沙一段和东三段好;平面上,各套烃源岩的成熟度在凹陷的中心部位表现更高,部分位置进入高成熟阶段,所以凹陷中心部位属于有利勘探区域。

On the basis of geochemical data analysis of source rocks in Liaozhong sag, the denuded strata thickness was calculated. Thereafter, several hydrocarbon generating simulation parameters were selected and the hydrocarbon generating simulations of Es3, Esl, Ed3 source rocks were carried out to analyze the hydrocarbon generating phenomenon. The results showed that the source rocks in Esl, Ed3 both had two periods hydrocarbon generation, and the hydrocarbon generation rate of source rocks in sedimentation cen- ter was higher than that in the basin slope. Due to the deeper burial depth, the greater sedimentary thickness, and the higher organ- ic matter abundance, the only one hydrocarbon generation period that source rocks of Es3 had better hydrocarbon generation effect than that in Es~ and Ed3. On the plane, the maturity of the source rocks was higher in the center of the depression. Part of the posi- tion entered the high mature period. Therefore, the central part of the depression was the favorable exploration area.