Method for evaluating wetting agent in oil base drilling fluid by adopting spectrophotometer

The invention discloses a method for evaluating a wetting agent in oil base drilling fluid by adopting a spectrophotometer. The method comprises the following steps: preparing the evaluated wetting agent in an oil phase according to preset concentration; and adding powder of a weighting material after the wetting agent is fully dissolved, fully dispersing the powder of the weighting material in the oil phase solution, standing the oil phase solution at a set constant temperature, taking the upper liquid after the preset time reaches, measuring the absorbance ratio by adopting the spectrophotometer, and judging the degree of wettability according to the absorbance ratio, wherein the larger the absorbance ratio is, the greater the dispersion of the powder of the weighting material in the oil phase solution is, the higher the capacity of changing the wetting performance of the weighting material by the wetting agent is, and the better the effect is, otherwise the performance is weaker. According to the method disclosed by the invention, the performance difference of the wetting agent in the oil base drilling fluid can be evaluated.