柴达木盆地油气资源研究现状及问题

柴达木盆地是我国西部重要的含油气盆地，地质条件非常复杂，发育了石炭系海陆过渡相、侏罗系湖相—湖沼相、古近系咸化湖相和第四系盐湖相4套不同类型的烃源岩层系。盆地的油气资源种类多样，柴西扎哈泉地区新近系上干柴沟组致密油、柴北缘鱼卡地区中下侏罗统页岩气、三湖坳陷第四系生物气等。在前人研究成果的基础上，总结了柴达木盆地油气资源的研究现状及问题，柴西地区一直是勘探的重点，常规的基岩油气藏和非常规的致密油共同开发，基岩油气藏存在埋藏深，地质构造复杂，勘探开发难度大，致密油具有有机质丰度、成熟度偏低，生烃转化率高的特点，因此难以应用常用的致密油评价方法对“甜点”进行预测；柴北缘地区页岩气发展迅速，但有机质丰度变化大、有机孔少，以次生孔隙为主，因此“甜点”预测难度较大；三湖地区生物气勘探时间长、分布广、资源量大，但鉴于特殊的地质背景，储层预测难度大。

Research status and problems of oil and gas resources in Qaidam Basin

Qaidam Basin is the most important oil and gas bearing basin in the west，which is complex and develops 4 kinds of hydrocarbon origin rock series of Carboniferous transitional facies，Triassic lacustrine-marshy，Paleogene salinized lake facies and Quaternary salt lake facies.Oil and gas resources in Qaidam Basin are various，including the tight oil of upper Ganchaigou Formation of Neogene in western Qaidam Basin，the shale gas of Middle-Lower Jurassic in Dakendaba Area in Northern Margin of Qaidam Basin and biogas of Quaternary in Sanhu depression.This paper summarized the research status and problems based on predecessor′s foundation:the area in western Qaidam Basin was always the key target，which the conventional basement hydrocarbon reservoir and the unconventional tight oil jointly were developed.Basement hydrocarbon reservoir possesses the problems of large-depth，complex geological structure and difficulty of exploration and development.Tight oil possesses the feature of low organic matter abundance and maturity，high rate of hydrocarbon conversion，which has difficulty predicting "dessert" by common methods of assessing tight oil.Shale gas developed rapidly in Northern Margin of Qaidam Basin，but organic matter abundance vary greatly，organic pores were lacking and secondary pores are dominated，which led to difficult dessert prediction.Biogas of Quaternary in Sanhu depression has the long exploration time，the extensive distribution and the large reserves.However in view of special geological background，reservoir prediction existed problems.