陆相烃源岩凝析油形成演化实验模拟特征

Characteristics of Condensate Oil Formation and Evolution from Continental Source Rocks Based on Simulation Experiments

为了解陆相烃源岩在深埋过程中凝析油形成与演化特征,利用高温高压生烃模拟仪对辽河盆地西部凹陷曙13井、马南603井和东部凹陷桃10井烃源岩样品进行了半封闭体系生烃模拟实验。实验结果显示,I型有机质(曙13井烃源岩样品)总凝析油产率峰值为2.32 mg/g TOC,出现在镜质体反射率(VR)1.76%Ro,并以低分子量烃类物质为主要成分,可能表明I型有机质凝析油主要通过液态烃二次裂解形成。II型有机质(马南603井烃源岩样品)总凝析油产率峰值为2.28 mg/g TOC,该峰值出现在VR为2.42%Ro,明显晚于I型有机质凝析油产率峰值,其成分以相对高分子量的烃类物质为主,其次为低分子量烃类物质。III型有机质(桃10井烃源岩样品)凝析油总产率最低,产率峰值仅为0.92 mg/g TOC,可能表明III型有机质生成凝析油潜力较差。

In order to investigate the generation and evolution of the condensate oil from the continental source rocks during deep burial,the high temperature and pressure simulation was conducted using samples from Shu 13,Manan 603 in the western sag and Tao 10 in the eastern sag of the Liaohe Basin.Results show that the maximum yield of condensate oil generated from type-I kerogen(source rocks from Shu 13)was 2.32 mg/g TOC,which occurred at the vitrinite reflectance(VR)of 1.76%Ro and the main components were hydrocarbons with low molecular mass.Those may indicate that such condensate oil mainly generated from secondary cracking of the liquid hydrocarbon.The maximum yield of condensate oil in type-II kerogen(source rocks from Manan 603)was 2.28 mg/g TOC,and appeared at VR of 2.42%Ro,which was obviously later than that of type-I kerogen.These condensate oil products were mainly composed of hydrocarbons with higher molecular mass and part of hydrocarbons with low molecular mass.The yields of condensate oil of type-III kerogen(source rocks from Tao 10)were the lowest and the maximum yield was only 0.92 mg/g TOC.Those results may indicate that the potential of condensate oil derived from type-III organic matter was poor.