西藏洞错盆地古近系丁青湖组烃源岩评价

洞错盆地位于西藏中部,为古近-新近纪陆相盆地,主要发育新近系康托组、古近系丁青湖组和牛堡组。对盆地地层、沉积相和烃源岩等评价分析后认为,丁青湖组泥岩、泥灰岩和灰岩为主要烃源岩,泥质烃源岩厚40 m,碳酸盐类烃源岩厚72 m. 其中泥灰岩及灰岩有机碳含量较高（平均值为0.51%）,属中等-好烃源岩。丁青湖组下段半深湖相的深黑色泥岩有机碳含量平均值高达5.92%,属优质烃源岩;有机质类型以Ⅰ、Ⅱ型为主;烃源岩热演化达到早期成熟阶段（热解峰温为431~456℃,镜质体反射率为0.36%~0.66%）。综合分析表明,洞错盆地具有较好的生烃潜力和勘探前景。

Evaluation of Paleogene Dingqinghu Source Rocks in Dongcuo Basin,Tibet

Dongcuo basin located in the central Tibet is a Tertiary continental basin,which is mainly composed of Neogene Kangtuo formation,Paleogene Dingqinghu formation and Niubao formation.The stratigraphy,sedimentary facies analysis indicates that the source rocks are dominated by mudstone,marl and limestone of Dingqinghu formation with a maximum thickness of mudstone of 40 m,carbonate rocks of 72 m.The TOC of marl and limestone averages 0.51%,belonging to medium-good source rocks.The TOC of the dark mudstone in l...