Abstract:

Two groups of Mesozoic and Paleozoic fractures developed in Chengdao Region,one strike is northeast 30°,the other is nearly east west.The fractures'dip angles are mostly more than 70° and their width is 0.3～2.0 mm.Most of the fractures formed in Himalayan Period,some of them formed in Yenshan Period.The fractures formed in Himalayan Period are distributed in the south and the north parts of Chenodao Region,they are fine reservoiring spaces and migration passages since their formation time matched well with hydrocarbon expelling stage.The fractures formed in Yenshan Period could form favourable reservoiring spaces and migration passages.

Key words: fractures, Mz～Pz, oil and gas, Chengdao Region