Research On The Mathematical Model And Numerical Simulation Of Microbial Flooding

After exploitation of water injection many years, most of the oil fields in the world are confronting with high water ratio and low R/P ratio austere circumstances. In order to improve recovery, people take EOR more seriously. Microbial enhanced oil recovery (MEOR) is considered as having good potential method for it's advantages, such as low cost, high adaptability, simple operation, non-pollution and non formation damage.In this paper, according to the growth kinetics of microbial and activities to rocks and liquids, the equations of microbial growth and properties of liquids and rocks changing have been developed. According to the law of conservation of matter, the equations describe microbial and metabolites transport and diffusion have been developed. Based on the change of oil and water permeability resistance before and after microbial, the model of MEOR has also provided. Put the partial differential equations into finite difference equations by scattering the model of MEOR on time and space, using the implicit pressure - explicit saturation (IMPES) to calculate the pressure and saturation, then according to the size of the water saturation to get the concentration distribution of micro-organisms and nutrient implicitly. Using this method, the numerical simulation software of microbe enhance oil recovery is developed. The software can run the numerical simulate calculation basically in the process of microbe flooding, and offers an available simulate method for using microbial technologies to enhance recovery efficiency.Taking the testing area of microbial flooding lying in Sanan intermediate belt of Daqing oilfield for example, we design the projects by using the software and obtain a optimum project by crosscut testing method. The optimum project is 106cell/ml of microbe concentration, 4% of nutrient concentration and 0.4PV. The prediction of numerical simulate shows that microbial flooding could increase oil yield 12.19×104t and enhance oil recovery 5.67%, under the optimum project.