Well Test Interpretation And Transient Deliverability Evaluation Of Non-Darcy Flow In Low Permeability Reservoir

In order to accuracy analyze well testing data and evaluate reservoir deliverability of low permeability reservoir with non-Darcy flow in oil exploration and production, we have studied low velocity non-Darcy flow theory, considered the effect of flow barrier, and yielded numerical solution bottom hole pressure change with implicit differentiation. Type curve chart and a non-Darcy well test interpretation software of low permeability reservoir are developed. The software has already applied in exploration and production of Daqing oil field. It can accurately evaluate low permeability reservoir and instruct sequent production operations. Achievement from the research concludes two aspects:First,A non-Darcy well test interpretation method of low permeability reservoir is developed with research work in this theme. The method takes starting pressure gradient into consideration. There are dozen interpretation models in the software. It can accurately evaluate low permeability reservoir and avoid the error that caused by evaluating non-Darcy flow reservoir with interpretation method of Darcy flow. It improves accuracy of well test interpretation and deliverability evaluation.Second,A non-Darcy deliverability evaluation method of low permeability reservoir is studied in this theme. Starting pressure gradient is taken into consideration when we predict well productivity decay curve with time. The method can accurately evaluate reservoir deliverability and it's very significant to instruct well production.At present, the non-Darcy well test interpretation method has already applied in 40 wells (42 layers) in Daqing oil field. Reservoir parameters are obtained from it, such as permeability, skin factor, starting pressure gradient, and so on. Therefore, low permeability reservoir characteristic is accurately evaluated. The non-Darcy deliverability evaluation method has already examined and applied in 29 wells (30 layers) in Daqing oil field. Flowrate calculated by the software is in accordance with actual measurement flowrate. Relative error between them of each well is in 20%. Well production vs. time curve in variable production flow pressure and transient IPR curve are calculated. We also predict oil well absolute open flow potential at 180d. It is very significant to instruct production, determine production flow pressure and flowrate, and arrange flooding network of those wells.