中亚沉积盆地常规油气资源评价

Evaluation of conventional hydrocarbon resources in sedimentary basins of central Asia region

在对中亚区域地质及含油气盆地基本石油地质条件分析基础上,选取滨里海、北乌斯丘尔特、北高加索、曼格什拉克、南里海、阿姆河、阿富汗—塔吉克、费尔干纳、南图尔盖、楚河—萨雷苏和斋桑11个已有油气发现的盆地为资源评价对象。根据各盆地纵向上储盖组合结合平面上构造单元划分及储盖分布情况,将11个含油气盆地共划分为33个成藏组合。基于各盆地勘探程度、资料掌握程度及评价方法适用条件,优选出适合各成藏组合评价方法。运用发现过程法或类比法对各成藏组合待发现可采资源量进行了系统评价,并和USGS(2000)评价结果进行对比和分析。结果表明,中亚大区待发现油气资源量大,但分布极不均衡,主要分布于阿姆河、滨里海和南里海三盆地。

The central Asian region has a total of 18 oil/gas fields discovered in a total of 11 basins, including PreCaspian, Amu-Darya, Mangyshlak, North Caucasia, North Ustyurt, South Caspian, South Turgay, Chu- Sarysu, Fergana, Afghan-Tajik, and Zaysan, etc. Through so many years of exploration, it is interesting to know how many potential resources are left and where are they distributed in these 11 basins. It is a main subject of this study. This paper uses USGS（2000）, I HS database, public domain literature, CNPC＇s new project evaluation data and in-house research results for the accessed basins （blocks） to study the basic petroleum geologic conditions of these 11 basins, and classify them into 33 plays. By referring to the exploration degree of individual basins, the availability level of data and the applicability conditions of evaluation methods, we selected discovery process method and analogous method as the methods for evaluating hydrocarbon resources. Based on the analysis of the impacts of critical parameters on resources evaluation results, proper evaluation parameters are selected, the quantity of hydrocarbon resources of individual basins is calculated, and these are correlated and analyzed together with the USGS（2000） evaluation results. According to the estimate of USGS（2000）, the remaining recoverable hydrocarbon reserve equivalent in the 6 basins of PreCaspian, Amu-Darya Mangyshlak, North Caucasia, North Ustyurt and South Caspian is 16.63 billion tons. As of the end of 2008, the newly discovered recoverable hydrocarbon reserve equivalent was 6.47 billion tons, therefore the remaining recoverable hydrocarbon reserve equivalent was 10.16 billion tons, and the reserves re-evaluation results for the above six basins are basically consistent with the results of USGS evaluation. This paper has also evaluated the reserves in the rest 5 basins which were not covered in the USGS （2000） evaluation. Our result indicates that the oil and gas reserve in the 11 hydrocarbon-bearing basins in the greater Central Asia Region is abundant, but the distribution of these resources is extremely unbalanced. The remaining recoverable oil/gas reserve is mainly distributed in the three basins of Amu-Darya, PreCaspian and South Caspian.