Generally when a well drains the hydrocarbons of an adjacent lease the hydrocarbons are deemed to be from the lease on which the well sits (i.e. if you’ve captured it you keep it).

Rule of capture is defined as “the legal rule of non-liability for (a) causing oil or gas to migrate across property lines and (b) producing oil or gas which was originally in place under the land of another, so long as the producing well does not trespass ( i.e. it does not penetrate into an adjoining licensed area)”