Regularities And Prediction Of Corrosion And Scaling In Formation During The Procedure Of ASP Flooding

ASP flooding will cause scaling in reservoir rock and production well. Scaling may cause reservoir block and stuck well pump. Scaling effects the application of ASP flooding seriously. Alkaline cause reservoir rock corrosion. Productions from corrosion may form scale such as silicate and carbonate.In order to study law of scaling and corrosion of reservoir rock, 5 main work were launched:(1)Alkaline consumption experiments on reservoir rock and ASP concentration were conducted. Experiments found chemical alkaline consumption occupies 32.5%, 43.6%, 44.8%, 60.0% and 62.2% of the total alkaline consumption separately. Illustrates that in the ASP combination system, main alkaline consumption way of clay mineral is physics adsorption, chemical consumption is the main consumption way for rock matrix.(2)Sacling mechanism of carbonate and silicate were analized. Proven that main reason of carbonate scaling is ion concentration product larger than solubility product constant, main reason of silicate scaling is silicon concentration, p H and metal ions concentration meets a critical value.(3)Based on the results of alkaline consumption experiment on reservoir rock and ASP concentration, order of chemical reaction and rate constant were confirmed. Modle of chemical reaction kinetics of alkaline consumption and silicon concentration were set up the first time. These models can study law of rock corrosion, alkaline consumption, and ions concentration change caused by well space, base type and slug combination.(4)Based on calculation results of chemical models, researches found that with the increasing of well space, main content of scale changes from carbonate to mixture of carbonate and silica. Main content of scale from well with strong base combination flooding is carbonate and silica, Main content of scale from well with weak base combination flooding is carbonate. Compared with single major slug, there produced more cilicate and silica when exists both major slug and sub slug. Total amount of carbonate changes little. Chemical reaction kinetics proves a theoretical support for studying law of reservoir scaling.(5)Aim at partical condition that many factors affect the scale content of ASP flooding production wells, basded on the ions data of liquid from production well, set up a method to predict scale content using the artificial neural network BP model. Compared with partical test results, relative error of the predict results of this method is less than 10%. This method provides a scientific way for predicting scale content of production well with ASP flooding.Through the above study, we can know the mechanism of scaling and influence factors of scaling and predict the scaling trend and contents of scale. Measures can be taken to prevent scaling from happening. This research is of great significance for the large scale industrial application of ASP flooding.