The reservoirs in Baota Formation of MiddleOrdovician in South Sichuan are characterized by low porosity and low permeability and belong to a fractured type.
川南地区中奥陶统宝塔组储层具低孔低渗特征，属裂缝性储集类型。
2
In early Ordovician North Qilian region again stretched and suffered second oceanization, up to middleOrdovician a mature ocean basin with a trough-arc-basin system already formed.
早奥陶世北祁连地区再次拉张，遭受第二次大洋化，到中奥陶世形成具沟弧盆体系的成熟大洋。
3
The main water source is fracture-karst water in MiddleOrdovician carbonate rocks.