Study On Scaling Rule In Gathering And Transporting Systems Of ASP Flooding

The alkaline-surfactant-polymer (ASP) flooding is newly developed to enhance oil recovery, now in the field experiment. Oilfield ASP gathering and transporting systems seriously scaled, affecting the normal oil production and economic efficiency. In this thesis, scaling mechanism and rule were researched, laying the theoretical foundation for the anti-scaling technology, providing a strong guarantee for ASP flooding successful application of enhanced oil recovery technology.By analyzing water quality of gathering and transporting systems, the main factors that affect the scaling were calcium, magnesium, silicon ions, the pH value and temperature. XRD diffraction and chemical analysis were used to analyze scale samples, showed that the main types were carbonate and aluminosilicate scale, drew the same conclusion.By simulating ASP fluid, silicate scaling rule of the four produced liquids simulated in laboratory were experimented, including the single-silicon solution, Ca²⁺,Mg²⁺ and silicon solution, Ca²⁺, Mg²⁺, Al³⁺and silicon solution, Ca²⁺,Mg²⁺,polyacrylamide and silicon solution. The higher the Ca²⁺,Mg²⁺ concentration and pH value, the more likely the formation of carbonate scale. together with the silicate precipitation, so was polyacrylamide, aluminum promote scaling also. According to orthogonal range analysis, the main factors affecting calcium scaling were the temperature, calcium concentration and flow of time. The higher the temperature and the calcium concentration, the faster the rate of calcium scaling. The main factors of silicon scaling were pH, silica concentration and temperature. the pH=8.5, the most silicon scale was. the lower the water temperature, silicate content, the more likely the formation of silicate scale.In order to better predict the scaling trends of gathering and transportation system, BP neural network was achieved on MATLAB 6.5, the error was established to meet the requirements of calcium carbonate scaling and scale simulation of silicon, calcium carbonate and silicate scale the accuracy rate was 93% and 96%.