On the basis of a new oil phase relative permeability curves

combined with the material balance equation and Welge equation

a new model for predicting water cut is derived.Under certain conditions

it can be converted to the Logistic model.In the new model

the relationship between undetermined coefficients

development dynamic and geological static parameters is clear

so many water control measures have become more theoretically supported.Meanwhile

combined with water-oil relative permeability curves and Welge equation

either the Logistic model

the Goempertz model or Usher model cannot be deduced.Furthermore

some limiting conditions remain in our solution

such the new model requires that the number of wells still not be changed.However

coupling and direct methods have been proposed to build prediction model of water cut.By means of expanding the two methods

with rich

diverse prediction models of water cut

it has been fully possible to describe the complex and diverse water content and process of time change.After field applications of the model

positive results are acquired

and thus may be applied to other oil fields.