中国与美国致密油形成条件对比研究

在拟定、完善致密油定义与内涵的基础上，对中国9个、美国6个共15个致密油盆地的成盆、成烃、成储、成藏进行类比研究。结果表明，中国致密油潜力大，但成藏条件复杂多变；中国有9个致密油盆地，分别位于中国大陆的东、中、西部三个构造区，由于受太平洋、西伯利亚、印度三大板块共同作用，导致了这三个构造区致密油盆地类型、规模、成盆、成烃、成储、成藏、富集的差异和有规律的变化趋势。具体表现在，由西部构造区到中部构造区再到东部构造区，致密油分布规模由小到大再到中，分布层位由上二叠统到中侏罗统再到下白垩统，层位数目由多到中再到少；致密油生成条件由差到好再到较好，储集类型由多而复杂到相对复杂再到相对简单，储集性能由相对好到相对差再到相对好，渗透率由相对高到相对低再到相对高；致密油运聚成藏条件由相对差到好再到较好，油藏类型由多到少再到多；致密油勘探开发潜力西部构造区最大，其次是中部构造区，再次是东部构造区。中美致密油盆地及致密油成藏既有共性也具有明显不同，差异的根本原因是构造的稳定性和沉积相的非均质性:中国致密油盆地构造稳定性差，陆相沉积，而美国致密油盆地构造稳定性好，海相沉积，从而导致中国致密油盆地的生烃能力比美国差，但储集条件总体好于美国。中国致密油的成藏机制与富集模式要比美国更为复杂和丰富，美国致密油的品质总体要好于中国致密油，盆地规模与致密油勘探开发潜力比中国大。 

A comparative study of geological conditions of tight oils in China and USA

On the basis of formulating and perfecting the definition and connotation of tight oil, a comparative study was carried out on the basin formation, hydrocarbon generation, hydrocarbon preservation and reservoir formation for 9 tight oil basins of China and 6 of USA. It was concluded that China′s tight oil has great potential, but the accumulation conditions are complex and diverse. There are 9 tight oil basins in China located in 3 tectonic areas in the eastern, middle and western parts of mainland China. Due to the combined action of the 3 plates of the Pacific, Siberia and India, the type, scale and formation of tight oil basins as well as the generation, preservation and enrichment of hydrocarbon are varied and have regular change trends among the three tectonic areas. From the western tectonic area to the central and then to the eastern one, the distribution scale of tight oil changes from small to large and then to middle, and the number of tight oil distribution horizon decreases from the Upper Permian to the Middle Jurassic and finally to the Lower Cretaceous. The generation conditions of tight oil changed from bad to good and to relatively good. The types of tight oil reservoirs change from multiple and complex to relatively complex and then to relatively simple. The reservoir performance of tight oil reservoirs changes from relatively good to relatively poor and to relatively good, while permeability changes from relatively high to relatively low and to relatively high. The conditions of tight oil migration and accumulation change from relatively poor to good and to relatively good, and the types of tight oil reservoirs change from more to less and back to more. The exploration and development potential of tight oil is the largest in the western tectonic area, followed by the central and then the eastern one. The tight oil basins and tight oil accumulations in China and USA have both commonalities and obvious differences. The fundamental reasons for the differences are the stability of structures and the heterogeneity of sedimentary facies. The tight oil basins in China have poorer tectonic stability and continental deposition, while the tight oil basins in USA have better structural stability and marine deposition. As a result, the hydrocarbon generation capacity of tight oil basins in China is worse than that in USA, but the reservoir conditions are generally better than those in USA. The accumulation mechanism and model of tight oil enrichment in China are more complex than those in USA. The quality of tight oil in USA is generally better than that in China. The size of tight oil basins in USA and the exploration and development potential of tight oil are greater than those in China.