| Low permeability reservoir plays an important role in our oil and gas resources,however, the development degree of super-low permeability reservoir is very low. Lots of experimental research has showed that the low permeability reservoir had the features of pressure sensitivity and threshold pressure gradient and there existed the nonlinear seepage during fluid flow. The potential productivity need evaluating for the better development of low permeability reservoir. However ,the productivity equation can not satisfy the demand of the reservoir at present. Firstly, the influencing factors of low permeability reservoir productivity were analyzed by the result of core flow test; a single phase and stable seepage numerical model has been established based on the percolation theory of low permeability reservoir and the productivity analytical formulas of 1-D plane radial and spherical seepage were derived considering the different influence factors. The influence of nonlinear factors on productivity was discussed and analyzed through the calculation on the same low permeability reservoir example with the derived productivity analytical formulas. It was demonstrated that the single phase seepage had the advantage by the comparison of different productivity curves in the same condition. Secondly, starting from the features of pressure-sensitivity and threshold pressure gradient, the stable productivity expression of artificial vertically fractured well was obtained and the influence of fracture, threshold pressure gradient and pressure-sensitivity on productivity was analysed in permeability isotropic and permeability anisotropic formations. At last, the elastic oil recovery prediction formula was deduced taking the plane radial seepage of super-low permeability reservoir as example and the limit value budget was gained by the account economic ultimate oil output correspondingly, which had the guiding significance on the development of low permeability reservoir at some extent.
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