克拉美丽气田油气成因及成藏特征

克拉美丽气田是近年来准噶尔盆地天然气勘探的又一重大发现,研究其油气成因及成藏特征对整个陆东地区下一步油气勘探具有指导意义。为此,对该区烃源岩进行了综合评价,认为滴水泉地区石炭系烃源岩有机质丰度高,已到高成熟演化阶段,具有较强生烃能力;通过对天然气组分、伴生原油碳同位素、轻烃及生物标志化合物特征进行综合分析,认为克拉美丽气田油气均属于腐殖型有机质来源的高成熟阶段产物,且原油碳同位素值具有从西到东变重的趋势;结合区域构造演化特征,指出滴南凸起存在“洼槽”,阻挡了东道海子凹陷油气运移至克拉美丽气田石炭系储层成藏,该气田的油气可能主要来自滴水泉凹陷西端的石炭系烃源岩;最后,建立了油气运移成藏模式,指出滴水泉凹陷周缘具有较大的勘探潜力。

Hydrocarbon origins and their pooling characteristics of the Kelameili Gas Field

The Kelameili Gas Field is another big discovery made in the Junggar Basin in recent years so that the study on its hydrocarbon origins and pooling characteristics is of great significance to future exploration in the whole Ludong area. A comprehensive evaluation of the source rocks of this gas field reveals that the Carboniferous source rocks in the Dishuiquan area have high organic abundance and have come to a higher mature stage, thus have a great potential of hydrocarbon generation. A comprehensive analysis of gas composition, carbon isotopes of associated crude oil, light hydrocarbons and biomarkers shows that all of the hydrocarbons in this gas field are products of humic type organic matter at high maturity and the carbon isotopes of crude oil are getting heavier from west to east. The study of regional structural evolution indicates that a "structural low" exists on the Dinan salient and prevents the hydrocarbons generated in the Dongdaohaizi sag from migrating into and accumulating in the Carboniferous reservoirs of the Kelameili Gas Field, the hydrocarbons of which mainly come from the Carboniferous source rocks in the western Dishuiquan sag. Finally, a model for hydrocarbon migration and accumulation is established and it is pointed out that the periphery of the Dishuiquan sag has great potential for hydrocarbon exploration.