温压共控生烃模拟实验烃类产率演化特征及地质意义

为探究深层环境“煤系”烃源岩生排烃潜力及生烃机理，利用WYMN?3型高温高压（HTHP）模拟仪对柴达木盆地北缘DMG1井中侏罗统烃源岩（Ⅲ型有机质，炭质泥岩和煤的R_O值分别为0.67%和0.64%）进行了半开放体系温压共控条件下的生排烃模拟实验。结果显示：①炭质泥岩和煤的最大总油产率分别为79.38 mg/g_TOC和37.30 mg/g_TOC，且总油产率整体呈“双峰”型演化规律；②较低演化阶段（T≤300 ℃，P≤42.0 MPa），2类源岩的排出油产率均小于残留油产率，排烃效率较低，但在400 ℃（51.0 MPa）排油/烃率大幅增加，分别达到了76.84%和83.72%；③排出油族组分主要为非烃和沥青质，其族组分产率演化特征也与液态烃产率演化规律总体相似，炭质泥岩排出油族组分产率整体较煤的族组分产率高；④模拟气主要由烃类气和非烃气（CO₂、N₂）组成，气态烃产率随着热演化程度的增加而升高，2类源岩最大烃类气产率分别为116.46 mL/g_TOC和36.85 mL/g_TOC；⑤镜质体反射率（R_O）均随温压条件的升高而增加，与温度呈良好的一致性变化规律。此次温压共控模拟实验结果表明，温度仍然是有机质热演化的主要因素，流体压力对Ⅲ型有机质烃产物的形成具有“双重”控制作用，“煤系”烃源岩在高过演化阶段仍具有较强生烃潜力。该研究为进一步认识柴达木盆地北缘侏罗系深层“煤系”烃源岩生排烃规律提供了一定的数据参考。

Hydrocarbon yield evolution characteristics and geological significance in temperature-pressure controlled simulation experiment

In order to explore the hydrocarbon generation and expulsion potential and mechanism of deep environment “coal measure” source rocks， a semi open system temperature-pressure controlled hydrocarbon generation and expulsion simulation experiment was carried out. We used WYNN-3 high temperature and high pressure （HTHP） simulator and Middle Jurassic source rocks （III type organic matter， carbonaceous mudstone and lignite，R_O is 0.67% and 0.64% respectively） of DMG1 Well in the northern margin of Qaidam Basin.The resul-ts demonstrated that： （1） the maximum total oil yields of carbonaceous mudstone and lignite were 79.38 mg/g_TOC and 37.30 mg/g_TOC， respectively， and showed a “double peak” evolution law as a whole. （2） In the lower evolution stage （T ≤ 300 ℃， P ≤ 42.0 MPa）， the expelled oil yield of the two types source rocks was lower than that of the residual oil， and the hydrocarbon expulsion efficiency was low， but the expelled oil yield increased significantly at 400 ℃ （51.0 MPa）， reaching 76.84% and 83.72%， respectively. （3） The discharged oil group components were mainly resins and asphaltenes， and the evolution characteristics of group components yield were also generally similar to those of liquid hydrocarbons. The yield of expelled oil group components of carbonaceous mudstone was higher than that of lignite. （4） The simulated gas was mainly composed of hydrocarbon gas and non-hydrocarbon gas （CO₂， N₂）， the yield of gaseous hydrocarbon increased with the elevated thermal evolution. The maximum hydrocarbon gas yield of the two types source rocks were 116.46 mL/g_TOC and 36.85 mL/g_TOC， respectively. （5） The vitrinite reflectance （R_O） increased with the increase of temperature and pressure conditions， and had a good consistency with the temperature. The results of this temperature-pressure co-controlled simulation experiment show that temperature is still the predominant factor in the thermal evolution of organic matter， fluid pressure has a “dual” control on the formation of type III organic hydrocarbon products， and “coal measures” source rocks still have strong hydrocarbon generation potential in the higher evolution stage. This research provided a certain data reference for the hydrocarbon generation and expulsion law of Jurassic deep “coal measures” source rocks in the northern margin of Qaidam Basin.