Preparation of a fluorescent polymer microsphere and stability evaluation of its profile control system by a fluorescence stability index

A quantitative stability evaluation method of a profile control system based on fluorescence intensity of fluorescent polymer microsphere was constructed due to the inaccurate measurement of conventional method. One kind of fluorescent polymer microspheres were prepared in this research, and microstructure of them was characterized by FT-IR spectra, laser particle size analyzer, inverse fluorescence microscope and ESEM. The swelling behavior of polymer microspheres was evaluated by weighing method. The fluorescent intensity of polymer microspheres was measured by fluorescence spectrometer. The stability influence factors and the stability mechanism of florescent polymer microsphere profile control system(FPMPCS) were studied using Fluorescent Stability Index (FSI) which was proposed in this research. The results show that higher polymer or surfactant concentration can promote the stability of the system. There is great influence of temperature on the system stability during the high temperature range, and every kind of polymer microsphere has an optimum salinity from the aspect of stability. There is a limit to improve the system stability by reducing the average size of fluorescent polymer microspheres. To improve the stability of this kind of system, bulk viscosity, the space barrier and electrostatic repulsion among the particles should be considered.