Karst reservoirs in Hercynian develop mostly in the area where Carboniferous strata directly overlay the mid-lower Ordovician, and the karst reservoirs in the area covered by upper Ordovician were formed in Caledonian.

• 海西期岩溶储层主要发育在石炭系直接覆盖于中下奥陶统之上的地区,上奥陶统覆盖区的岩溶储层主要是加里东期岩溶作用形成的。