Productivity Research Of Tight Sandstone Reservoir Based On Flow Unit

The exploration and development of tight sandstone reservoirs has been paid more and more attention.Compared with the conventional reservoir,the poor physical property and its complicated seepage mechanism make it hard to predict the productivity.Based on the analysis of Yanchang formation in Ordos Basin,the paper forms a productivity prediction system of tight sand oil reservoir,which can be used in the reservoir project design,by the hydraulic flow unit theory and engineering mathematical methods.Firstly,based on the core analysis data and production data,the parameters such as porosity,permeability,SH,FZI and flow factor were selected as the basis of flow unit.Cluster analysis was used to analyze the reservoirs are divided into four flow units,the establishment of four types of mobile unit discriminant function,the results will be extended to the whole section.Construction of Flow Units Geological Model by Sequential Gaussian Simulation.In order to accurately predict the production capacity of tight oil,based on geological and development factors,the key control factors of each flow unit are obtained by grey analysis method.A fractured vertical well productivity prediction model considering threshold pressure gradient and stress sensitivity is constructed,and then developed into four,combined with the key control factors and the threshold pressure gradient equation,and finally the classification capacity prediction model is obtained.Finally,based on the flow unit model,the production capacity prediction is carried out by the numerical simulation method.The classification capacity model is consistent with the actual production capacity.The results show that the method is reliable and applicable.Finally,based on the geological model of the flow unit,the production capacity of each flow unit is predicted,and the result can be used to guide the postproduction design of the research area.Therefore,the establishment of tight sandstone reservoir production capacity prediction system for the actual production and development has a certain guiding significance.