Study Of Well Test And Analysis Of Non-Darcy Flow In Low Permeability Reservoir

Low permeability oil and gas resource of China has a great potential of exploration and development. At present, considerable progress has been made in low permeability oil reservoir exploration. Well test and analysis technology to develop low permeability oil reservoir is needed. However, low permeability reservoir has characteristics of compactness, strong heterogeneity, fierce low permeability, low seepage velocity and so on. Therefore, conventional well test and interpretation technology cannot meet our needs. So studies on well test and analysis of non-Darcy flow under heterogeneous and low permeability oil reservoir will make great sense. In consideration of characteristics of heterogeneous and low permeability reservoir, the governing equations of low-velocity non-Darcy flow were deduced, deriving from the theory of permeation fluid mechanics and based on kinematic equation which takes start-up pressure gradient into account. The concrete research contents and achievement are:1. Deduction of the governing equations of low-velocity non-Darcy flow In consideration of the existence of start-up pressure of the flow and heterogeneity of the reservoir, the governing equations of low-velocity non-Darcy flow has been deduced.2. Study of the mathematical model of well test and analysis for radial heterogeneous reservoir The mathematical model of well test and analysis for radial heterogeneous reservoir has been established, and the numerical solution of this model has been obtained via studying the numerical solving methods of the model. Also, the pressure has been plotted along with its differential coefficient. The characteristics of the curves were analyzed and discussed.3. Study of the mathematical model of well test and analysis for plane heterogeneous reservoir The mathematical model of well test and analysis for plane heterogeneous reservoir has also been established, and the numerical solving methods have been researched until numerical solution has been obtained. As the model for radial heterogeneous reservoir, the pressure has also been plotted along with its differential coefficient. The characteristics of the curves were analyzed and discussed.4. Development of the software, which can interpret well test data of heterogeneous and low permeability reservoir Based on the study on the two mathematical models above, the software, which can interpret well test data of heterogeneous and low permeability reservoir, has been developed, using Visual Basic 6.0 program language. Has been tested and verified, the software can provide well test and analysis technical assistance for heterogeneous and low-permeability reservoir developing.