Distribution and transforming effects of low permeability reservoirs in Dongying Depression

The low permeability reservoirs（LPR）proved before 2001 in Dongying Depression are distributed mainly in depression, central anticline, and northern steep slope. The main sedimentary systems of LPR are deep water turbidite fan in Es3, shore sand beach bar and fan delta front in Es4. The main types of LPR are lithologic reservoirs, followed by structural lithologic reservoirs. The features of LPR are middledeep burial depth, atmospheric-extra high pressure, low-middle yielding, mini-small scale, low abundance, and etc. The oil testing of LPR in exploration wells experiences a process from acidification to fracturing. Good effects have been achieved from acidification in sand LPR with high carbonate content in Es4, while good effects have been achieved form fracturing in sand LPR with high clay content in Es3.