神农架复背斜北缘牛蹄塘组页岩气成藏主控因素分析——以SD1井为例

神农架复背斜北缘与黄陵背斜东南缘地区具有相似的构造地质背景,同样处于古老隆起的边缘,周缘地区在下古生界发育多套富有机质页岩,此前该地区页岩气地质调查和评价工作很薄弱,基本属于空白区。针对寒武系牛蹄塘组的页岩气地质调查井SD1井在深度1045 m钻获页岩气,不含残余气的现场解析气量均值0.25 m³/t,并成功点火,打开了该地区页岩气勘探新局面;研究发现,较深水的沉积环境、一定厚度的含炭烃源岩、适度的热演化过程以及复杂构造背景区相对稳定的地质构造条件是该地区页岩气成藏并保存的主要因素。

Analysis of Main Controlling Factors of Shale Gas Accumulation in Niutitang Formation on the Northern Margin of Shennongjia Compound Anticline

The northern edge of the Shennongjia compound anticline and the southeastern edge of the Huangling anticline have similar tectonic geological backgrounds.They are also on the edge of the ancient uplift.There are many sets of organic-rich shale in the lower Paleozoic in the peripheral area.Before that the evaluation work was very weak and basically belonged to a blank area.For the shale gas geological survey well SD1 of the Cambrian Niutitang Formation,shale gas was drilled at a depth of 1045 m.The average on-site analytical gas volume without residual gas was 0.25 m³/t,and it was successfully ignited,opened a new horizon for shale gas exploration in this area.Research has found that deep-water depositional environment,a certain thickness of carbon-bearing source rock,moderate thermal evolution process,and relatively stable geological structure conditions in complex structural background areas are the accumulation and preservation of shale gas in this area major factor.