内蒙古扎鲁特盆地深部林西组发育特征——来自大地电磁探测的依据

为了进一步了解扎鲁特盆地晚古生界林西组的空间发育状况,评价林西组的油气资源前景,在扎鲁特盆地部署完成了多条大地电磁测深(MT)剖面和音频大地电磁测深(AMT)剖面.根据大地电磁测深结果分析了扎鲁特盆地林西组的残留厚度、埋藏深度及平面展布状况,表明扎鲁特盆地深部林西组十分发育.依据其残留厚度可进一步划分为“三坳两隆”5个次级分区,即:北部坳陷区、中部隆起区、中部坳陷区、南部隆起区和南部坳陷区.林西组在3个坳陷区的发育规模较大,中部坳陷区的面积最大.超过300km2.坳陷区内残留厚度普遍超过1000m,底界埋深平均超过1200m,并被早中生界地层所覆盖.结合其它资料综合分析认为,扎鲁特盆地林西组具有寻找页岩气等非常规油气资源的潜力.

The development of Linxi Formation in the depth of Zhalute basin: Evidence from magnetotelluric sounding

In order to further understand the development of Linxi Formation in Zhalute basin, Inner Mongolia, the authors arranged several magnetotelluric sounding (MT) profiles and audio magnetotelluric sounding (AMT) profiles. The residue thickness, buried depth and distribution of Linxin Formation were calculated based on the MT profile survey, and the results show that the strata of Linxi Formation are developed extensively in the basin, which can be further divided into five secondary segments, i.e., the north depression, the middle uplift, the middle depression, the south uplift and the south depression; among them the middle depression occpies the largest area of about 300km2. Linxi Formation is well developed in depression zones, covered by early Mesozoic strata which become thinner in the west and thicker in the east, and the thickness of Linxi Formation is estimated to be generally over 1000m. In combination with other geological and geophysical data, it is held that Linxi Formation in Zhalute basin has great potential for the exploration of hydrocarbon resources, especially for the exploration of unconventional hydrocarbon resources such as shale gas.