Abstract: The Anpeng deep reservoir in Miyang sag is characterized by a dense sandstone reservoir with low porosity and permeability, but the deep reservoir conditions were improved due to its developed fractures. Study shows that the fractures mainly consist of high-angle fractures and horizontal fractures dominated by tensile stress,of which high-angle fractures are distributed as "X" joint on anticlinal crest; the reservoirs reconstructed by the fractures become Type A reservoirs; petroleum is still remained in pores of basement rock, the fractures only play a part of increasing permeability in parallel to their extensive directions, and developed in the main part of greater deformation of the nose-like structure.

Key words: Miyang sag, deep bed, dense formation, reservoir, fracture