Most asphaltens consist of polyaromatic rings. These rings, stacked by association, lead to a crucial problem for oil wells, mainly in porous media. The purpose of this paper is to discuss the anisotropy reorientation from T-1 and NOE C-13 NMR data, using Huntress's equations. The method used here follows a previous study and completely corroborates it, and is easier to use. (C) 2003 Elsevier Science Ltd. All rights reserved.