罗子沟盆地白垩系大拉子组烃源岩特征及评价

Characteristics of hydrocarbon source rock and evaluation of Cretaceous Dalazi Formation in Luozigou Basin

大拉子组上段是罗子沟盆地的主要生油层。通过对大拉子组系统取样和多项地球化学指标测试,分析了罗子沟盆地烃源岩的有机质丰度、有机质类型及成熟度等。综合研究表明:大拉子组上段有机碳含量为0.94%～10.69%,平均4.72%;有机质类型主要为Ⅰ型,其次为Ⅱ1型;最大裂解温度(Tmax)为425℃～444℃,平均为436℃;镜质体反射率Ro为0.624%～0.88%,平均值为0.64%,烃源岩已经进入生烃门限。地化数据分析显示大拉子组烃源岩为较好烃源岩。

The Upper Member of Dalazi Formation is the main oil source rocks in Luozigou Basin. By systematic sampling and geochemical indicator testing, we analyzed the organic abundance, types and maturity of the drohycarbon source rocks. The organic content of hydrocarbon source rocks of the Dalazi Formation is 0. 94% to 10. 69%, averaging 4. 72%. The organic type is mainly the type I , and then the type II l- The maximum pyrolysis temperature （Tmax） is from 425℃ to 444℃, and averaging 436℃. The vitrinite reflectance （Ro） is from 0. 624% to 0. 88%, averaging 0. 64%. The geochemical data indicate that the hydrocarbon source rocks of the Dalazi Formation are better in quality.