Abstract: There has a great oil and gas exploration potential in Lower Karamay Formation of 530 Well Block. However, the large differences of productivity between single wells have hindered further exploration and development work. Sedimentary and reservoir characters are searched based on combination of macro and micro data, such as observation of cores, logging, grain size, thin section, high pressure mercury injection, physical property and sentimental experiment, and make evaluation on productivity is made non-producing area with geology and engineer parameters by grey relation way. The results show that favorable reservoir micro-face is distributary channel, and development area of S2–4 and S2–5 can be enlarged by distribution trend of distributary channel. Main reservoir rock in S2 sand group is gravel, and the reserve space comprises of secondary pores and micro-faults which make pore structure complex, and the relationship between pore and permeability, grain size and oiliness is good. Engineer parameters have deeper affection on S2–4 and S2–5 reservoir productivity than geology parameters, and development potential of S2–4 and S2–5 reservoir is large.

Key words: S2 sand group, Lower Karamay Formation, sedimentary character, reservoir character, productivity evaluation