Abstract: There are six grey models of dynamic prediction of oil and gas fields, but an appropriate model should be selected according to a certain oil or gas field in practice. Starting with the relation degree, this paper has presented a method for selecting a grey model,which could best fit the oil and gas field. And some practical examples have proved the method to be correct. Therefore, the blindness in selecting a grey model can be avoided. On the other hand, the quantitative description of the mutual influence.

Key words: Grey Model, Oil-gas fields Dynamic prediction, selection, Relation degree