河套盆地生物气成藏条件及勘探前景  

Accumulation Condition and Exploration Prosects of Biogenic Gas in Hetao Basin

作　　者：杨华[1] 李民才[1] 崔永平[1] 

机构地区：[1]长庆油田分公司,陕西省西安市710021

出　　处：《中国石油勘探》2005年第3期16-21,共6页China Petroleum Exploration

摘　　要：河套盆地呼和坳陷第四系、上新统气源岩厚1200m以上,有机碳平均含量0.59%,有机质类型为混合型及腐殖型,未成熟,处于生物化学生气阶段,具有大规模生气能力。大量水文浅井冒气泡,证实了生物气的存在。储层为浅湖、半深湖相粉细砂岩、泥质粉砂岩,成岩程度低,岩性疏松,孔隙度大于20%,储气能力强。第四系150～300m段发育泥岩及芒硝、腐殖土,具有较强的封盖能力,是比较理想的盖层段。生物气富集的主要控制因素为圈闭。通过类比,河套盆地成藏条件与柴达木盆地相似,资源潜力大,勘探前景好。The depth of Quaternary and Pliocene source rocks deposited in Huhe depression, Hetao Basin, is more than 1200 m, in which the content of organic carbon (OC) averages 0.59%,and organic matter includes mixing and humic types, source rocks are immaturity and have the ability to generate much gas. The air bubbles emitted from many hydrologic shallow wells can confirm the existence of biogenic gas.The reservoir rocks consist of shallow-and half-deep lacustrine facies silty-fine sandstones, argrillaceous silty sandstone, with low diagenesis and relatively loosen rocks, so the porosity of reservoir is usually more than 20%, reulting in high-quality reservoirs. Mudstone, mirabilite and humic soil developed on the Quaternary section of 150-300m, which has relatively high sealling feature and it can become ideal cap rock.The concentration of biogenic gas is mainly controlled the trap. By contrasting, it is found that the accumulation condition of biogenic gas in Hetao Basin is same as that in Qaidamu Basin, it has a potential of gas resources and promising prospects of exploration.

关 键 词：河套盆地 勘探前景 成藏条件 生物气 有机质类型 泥质粉砂岩 柴达木盆地 生物化学 生气能力 储气能力 300m 封盖能力 控制因素 资源潜力 第四系 气源岩 上新统 有机碳 混合型 冒气泡 孔隙度 腐殖土 坳陷 水文 储层 湖相 

分 类 号：P315.5[天文地球—地震学] P618.13[天文地球—固体地球物理学]