摘要：In this paper, we conducted NMR (nuclear magnetic resonance) experiments on 93 tight sandstone samples collected from the Permian Shihezi Formation in the Sulige gas field. The T_2 relaxation time response characteristics and their fluid identification ability of different types of pores were analyzed. We found six types of typical T_2 relaxation time spectrum in the studied tight sandstone, indicating that small pores (0.1 〜0.5µm) are most developed, followed by mesopores (0.5 ~2.5µm)and mi- cropores (<0.1 µm), there are few macropores (2.5 〜 10 µm), and cave (> 10 µm) is almost non-existent. The T_2 cut-off value of the tight sandstone is mainly distributed between 1 ms and 15 ms, with an average of 5.5 ms. The movable water saturation ranges from 1% to 18% with an average of 6.2%. There is a good negative correlation between T_2 cut-off value and movable water saturation. For the development of this tight sandstone gas reservoir, we should prefer the gas layer with gas saturation greater than 50% and movable water saturation smaller than 8%. When the movable water saturation in the formation is greater than 11%, the gas-bearing layer generally has no development value. In the current development stage, the target reservoirs will still maintain a higher gas production capacity under reasonable construction measures and reservoir protection conditions.
关键词：NMR;Tight gas sandstone;T_2 relaxation time;Movable water saturation;Gas production capacity
