辽河盆地生烃史的数值模拟

Numerical modeling of hydrocarbon-generating history in Liaohe Basin

基于对辽河盆地烃源岩的埋藏史、热演化史的准三维 ( X,Y和纵向的地质层段 ,加时间 )模拟 ,采用热模拟实验生烃率法建立了辽河盆地烃源岩的生烃史准三维计算模型 ,计算了不同层段在不同时期的生烃强度与生烃量 .在计算辽河盆地生烃量的同时 ,亦对资源量进行了估算 .模拟结果表明 :辽河盆地生油量为 70 0 .8× 1 0 8t,生气量为 5 9.6× 1 0 11m3 ;在 35 0 0 m以下生油量为 341 .3×1 0 8t,生气量为 1 8.8× 1 0 11m3 .西部凹陷的生烃量最多 ,东部凹陷的生烃量次之 ,大民屯凹陷面积最小 ,但有很好的生盖条件 ,其生气量与东部凹陷相当 .根据排聚系数估算出辽河盆地天然气资源量为 1 439.87× 1 0 8m3 .

Based on the simulation of quasi 3D model ( X,Y , vertical geological layers and time) of the buried history and maturity history of hydrocarbon source rock in Liaohe Basin, a quasi 3D model of hydrocarbon generating history is built by the result of thermal simulation test. The hydrocarbon generating intensity and hydrocarbon generating amount of every layer of every depression, in every epoch, are computed according to the model. The simulation result shows: the oil generating amount in Liaohe Basin is 700.8×10 8 t, and its gas generating amount is 59.6×10 11 m 3; below 3 500m, the oil generating amount is 341.3×10 8 t, and the gas generating amount is 18.8×10 11 m 3. The west depression has the most hydrocarbon generating amount, and the east depression takes secondary place. Although Damintun depression has the smallest area, its gas generating amount is approximate to that of the east depression because of its fine generating and lying conditions. According to expelling aggregating coefficient, the estimation amount of gas resource in Liaohe Basin is 1439.87×10 8m 3.