The use of solar photocatalytic degradation of pollutants is one of the most promising technologies to solve water pollution problems and achieve solar energy conversion. By changing the amount of g-C₃N₄ added, g-C₃N₄/Co₃O₄ catalysts with different g-C₃N₄ mass fractions are prepared based on the calcination method with cobalt nitrate hexahydrate (Co（NO₃)₂-6H₂O) and urea (NH₄CNO) as raw materials. The samples are analyzed and characterized using X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and ultraviolet visible absorption spectroscopy （UV-vis DRS）. To speculate on the active species of the catalyst, capture agent experiments are conducted on it. The results indicate that the synergistic effect between g-C₃N₄ and Co₃O₄ can improve the transfer and separation efficiency of charge carriers at the interface between the two phases. Under visible light, the degradation effect of 10% g-C₃N₄/Co₃O₄ is the best, with a degradation rate of 66.50%, which is higher than the degradation effect of single Co₃O₄ （degradation rate of 35.90%）. The active species of the catalyst are mainly superoxide radicals（·O₂-） and holes（h⁺）. After compounding with g-C₃N₄, the drawbacks of Co₃O₄ electron hole pair, such as too fast recombination and a deficient energy level structure, are improved, providing ideas for the degradation of organic pollutants in the future.

To solve the problems of reducing plug removal effect and lower effective period in Bohai Sea oilfield, strategy by expanding plug removal radius, optimizing plug removal agent system to enhance plug removal effect is considered. Through process research and optimization, a new deep penetration plug removal technology has been figured out. Deep penetration plugging removal technology mainly includes three process, including matrix plugging removal, fracture reduction and deep reservoir plugging removal. The mechanism of deep penetration plugging removal technology is studied forming a set of applicable technology. In view of the plugging problem in polymer injection wells in Jinzhou oilfield, a composite plugging remover was optimized, based on the results of polymer solution viscosity reduction, simulation of polymer?containing plugging material, and actual degradation of polymer?containing plugging material. Construction program was formed by considering the process program, and applied in the field. The effect of increasing liquid and oil is improved .