摘要
为了重新认识鄂尔多斯盆地上三叠统延长组长4 +5段湖相泥岩的生烃潜力 ,对其进行了有机地球化学综合研究和油源对比 ,利用单井盆地模拟恢复了其生烃史 ,并进行了生烃强度分析和生烃量计算 ,结果表明 :长4 +5段湖相沉积范围近 6× 1 0 4 km2 ,长4 +5段湖相泥岩有机质丰度较高 ,氯仿沥青“A”质量分数多数超过 0 .2 % ,有机碳含量和生烃潜量 S1+S2 分别在 0 .5 4 %～ 4.87%和 0 .5 8～8.0 8mg/g之间 ,属于中等到较好的烃源岩 ;长4 +5段湖相泥岩有机质类型以 型为主 ,泥岩样品热模拟烃产率达 447.2 6 mg/g TOC,具有很高的生烃潜力 .长4 +5段湖相泥岩生物标志物特征与中生界原油和长 7段泥岩相似 .长4 +5段泥岩 Ro值在 0 .5 8%～ 0 .96 %之间 ,现处于低成熟到成熟阶段 ,地史上距今 1 1 0～ 90 Ma处于生油窗阶段 ,最大生烃强度 40× 1 0 4 t/km2 ,期望生烃量 1 1 1 .1 3× 1 0
Geochemical comprehensive research of the reservoir is carried out and oil source correlation is analyzed for further recognizing hydrocarbon-generating potential of lake facies mudstone of Chang 4+5 member. By basin modeling of single well its hydrocarbon-generating history is obtained. Hydrocarbon-generating intensity is analyzed and the hydrocarbon quantity generated from lake facies mudstone of Chang 4+5 member is computed. It is shown that the sedimentation of lake facies mudstone covers about 6×10 4km 2. It belongs to medium to better hydrocarbon source rock, which has higher organic matter abundance, its content of chloroform bitumem 'A' generally exceeds 0.2%, and TOC and S 1+S 2 are at the range of 0.54%~4.87% and 0.58~8.08mg/g respectively. Therefore, the lake facies mudstone possesses quite high hydrocarbon-generating potential, whose organic matter is mainly typeⅡ, and hydrocarbon-generating quantity of simulated sample reaches to 447.26mg/g TOC. The biomarker character of Chang4+5 mudstone is similar to that of Mesozoic oil and Chang7 mudstone. The value of Ro of Chang 4+5 mudstone is 0.58%~0.96%, and it is in the stage of low mature to mature. The Chang4+5 mudstone is in oil-generating window 110~90Ma(b.p), the maxium of hydrocarbon generating intensity of it reaches to 40×10 4t/km 2, the expected hydrocarbon-generating quantity is 111.13×10 8t.
出处
《西安石油学院学报（自然科学版）》
2003年第2期9-13,共5页
Journal of Xi'an Petroleum Institute（Natural Science Edition)
关键词
鄂尔多斯盆地
长4+5段泥岩
生烃潜力
Ordos Basin
Chang4+5 member mudstone
hydrocarbon-generating potential
