塔里木盆地石炭系卡拉沙依组烃源岩研究

Source rock characteristics of the Carboniferous Karashayi Formation in the Tarim Basin

为了进一步搞清楚塔里木盆地石炭系各个层系烃源岩发育的规模,达到对石炭系烃源岩深入研究的目的,对石炭系卡拉沙依组碎屑岩开展了有机质丰度、厚度、分布范围以及有机质类型和成熟度研究。结果表明,卡拉沙依组砂泥岩段发育的时期是卡拉沙依组优质烃源岩发育最重要阶段;卡拉沙依组砂泥岩段潟湖相分布的区域,即以玛参1井为中心的玛扎塔格构造带附近是优质烃源岩分布最好的区域,甚至优于塔西南山前带,在这一区域中有机碳含量大于2%,厚约60 m,处于低成熟-成熟的过渡阶段。但是,总体上看,塔里木盆地卡拉沙依组优质烃源岩分布相对局限。

The organic matter abundance, thickness, distribution range, organic matter type and maturity of clastic rocks in the Carboniferous Karashayi Formation were studied in order to further clarify the scale of hydrocarbon source rocks in the Carboniferous strata in the Tarim Basin. The period when sandstones and mudstones were deposited in the Karashayi Formation was the most important period for the generation of high quality hydrocarbon source rocks. The lagoon facies area close to the Mazatage structural belt with Macan1 well at the center is the best area for high quality source rocks, even better than the southwestern Tarim Basin. Source rocks in this area are about 60 m thick, generally low mature or mature. The organic carbon content is greater than 2%. However, in general, the distribution of high quality source rocks in the Karasayi Formation of the Tarim Basin is relatively limited.