Research On Numerical Well Testing Analysis Method In Sandstone Reservoir With Multiple Wells

The strong heterogeneity of the sandstone reservoir itself and the long-term use of water injection for exploitation will cause changes in the pore structure of the reservoir,and it is easy to form advantageous seepage areas or advantageous seepage channels,resulting in reduced water flooding efficiency and impaired development benefits.Oilfields often carry out long-term production according to a certain water injection well pattern.All interconnected oil and water wells are used as a production system,and there are different degrees of mutual interference.However,the current research on the pressure dynamics of heterogeneous sandstone reservoirs under multi-well conditions is still need to be improved.Taking well testing analysis technology as the main research method,this thesis summarizes and analyzes the reasons for the formation of dominant seepage channels from the three factors of geology,development and fluid,and characterizes the dominant seepage channels through three parameters: width,conductivity and length of dominant channels.According to the common well pattern layout characteristics,various types of single-well and multi-well numerical well testing models are established and solved,and the influence of two factors,reservoir heterogeneity and multi-well interference,on the well testing pressure and its derivative characteristic curve is analyzed.Finally,a set of numerical well testing analysis methods that can quantitatively identify the dominant seepage channels between wells in sandstone reservoirs under multi-well conditions are obtained.In the actual application process,firstly,based on the actual production performance data of the oilfield and the CRM method,the inter-well connectivity is qualitatively judged,and the numerical model with the dominant channel is initially established by the numerical well test analysis method,and then the well test interpretation model is quickly selected according to the characteristics of different pressures and their derivative curves.By continuously adjusting the relevant parameters of the inversion model,a good fitting effect on the pressure data of the well group containing the dominant channel is achieved.According to the fitting results,the quantitative inter-well connectivity is obtained,and the interference degree of the adjacent wells is determined,which can provide reasonable well test interpretation to the properties distribution and pressure variation of the actual well group.The research results show that the numerical well testing analysis method established in this thesis under the multi-well condition of sandstone reservoir can effectively evaluate the pressure dynamic data of the development block with the dominant channel and the multi-well condition.