准噶尔盆地南缘天然气成因与成藏解剖

Natural Gas Genesis and Formation of Gas Pools in the South Margin of Junggar Basin

利用全烃地球化学方法 ,结合准噶尔盆地南缘三排构造特点 ,在确认油气源和天然气成因的基础上 ,对呼图壁气田、吐谷鲁和齐古油气田进行了成藏历史分析和解剖。研究表明各构造带不仅捕获了喜山期侏罗系高熟煤成气 ,这是该区天然气成藏的关键 ,而且还聚集有燕山期侏罗系低成熟—成熟阶段的油气 ,但不同构造带对这一阶段的油气的聚集量、方式和保存作用不同 ,第一排构造直接捕获大量侏罗系低成熟—成熟油气 ,但天然气的散失严重 ;第二、三排构造存在白垩系—下第三系中转侏罗系低成熟—成熟油气的特征。最后阐述了准噶尔盆地南缘进一步寻找天然气的勘探方向。

By using the whole hydrocarbon geochemistry method, combined with the three row structures characteristics in the south margin of Junggar basin, based on the oil-gas sources and the natural gas genesis, the formation history of oil-gas pools in Hutubi, Tugulu and Qigu has been analysed deeply. It is ascertained that the each row structure not only succeeded in catching the Xishan period high mature coal-measure gas in Jurassic, which is the key to form gas pools, but also gathering the Yanshan period low and mature stage oil-gas from Jurassic, but the gathering measures, catching ways and preserving conditions are different for this stage of oil-gas in different structures, the first row structure succeeds in catching the large quantity low and mature oil-gas from Jurassic, but natural gas loss is serious; The second and third row structure exist the middle-turn low and mature Jurassic oil-gas from Cretaceous-Jurassic floors. The article finally points out the exploration direction of gas pools in the south margin of Junggar basin.