巴彦浩特盆地石炭系烃源岩特征与评价

CHARACTERISTICS AND ESTIMATE OF CARBONIFEROUS SOURCE ROCKS IN BAYEHOT BASIN

以地表和井下烃源岩样品分析数据为依据,阐述巴彦浩特盆地石炭系烃源岩的分布、地化特征及影响因素,并进行综合评价。研究结果表明,巴彦浩特盆地发育暗色泥岩、灰岩2种源岩,分布于中、下石炭统臭牛沟组、靖远组和羊虎沟组。暗色泥岩有机质丰度中等—好,以腐泥—腐殖型和腐殖型为主,普遍进入成熟—高成熟阶段,是好的烃源岩。碳酸盐岩有机质丰度较低,具有一定的生烃能力,但厚度较小,分布局限,生烃潜力不大。沉积环境和构造运动对有机质丰度和热演化程度影响较大。巴彦浩特盆地有利生油区分布于乌达—巴参2—锡1井—查汗布勒格以北的北东向展布的滨浅海三角洲及近岸浅海环境沉积区。

According to analyses data of source rock samples from surface and underground,it is described in this paper distribution,geochemical characteristics and influential factors of Carboniferous source rocks in the Bayehot Basin.2 types of source rocks are generated in the basin： dark mudstone and limestone,mainly locating in the Chouniugou,Jingyuan and Yanghugou Formations of the Middle-Lower Carboniferous.Dark mudstone works as good source rock,with middle-good organic abundance,sapropel-humic and humic organic types as well as mature-high mature generation stage.Carbonate with lower organic abundance can generate certain hydrocarbon,yet has poor generation potential with less thickness and limited distribution.Sedimentary environment and tectonic movement have great influence on abundance and thermal evolution extent of organic matters.The most favorable source area of Bayehot Basin distribute in the sedimentary area of littoral-neritic delta and near-shore shallow sea facies trending NE to the north of Wuda-Bacan2-Xi1-Chahabuleg.