Аннотация:Summary This paper presents a model for analysis of changing wellbore storage during well testing. Our model is based on a modification and extension of a model for wellbore phase redistribution. The result is a general solution in Laplace space that can be used to add changing storage to a variety of weill reservoir models. Increasing and decreasing storage cases can be accounted for analytically. We present several field examples to show the application to well tests with changing wellbore storage.