Abstract: With common permeability reservoirs coming into their low productivity periods,the development of lowpermeability reservoirs becomes more vital.But the performance analysis prediction of reservoirs is very difficult because threshold pressure gradient.Based on investigation results,the prediction of inflow performance in lowpermeability solutiongasdrive reservoirs existing threshold pressures is presented.There is a linear relation between productivity index and bottomhole flow pressure.The inflow performances in different reservoir pressure are connected with ultimate PI.According to the fluid PI,a new calculating method that predicts future threephase flow performance of vertical wells in lowpermeability reservoir is established.The application of 23 sets of oil field data to validate the models shows that the average calculation errors is within 11%.The established predicting future IPR is suitable for different cases and can be widely used in practice.

Key words: low permeability reservoir, threephase flow, IPR, prediction, application