Towards Faster Amott Index Measurement: Amott Express Technique
Year: 2026
Type: article
Abstract: Wettability of oil reservoirs is a crucial parameter influencing hydrocarbon recovery. The Amott and United States Bureau of Mines (USBM) indices are commonly used to evaluate the wettability of reservoir rocks. However, traditional methods often require cell loading/unloading operations between different phases of the experiment, which imposes handling and therefore more errors and uncertainties. In this paper, we present the Amott Express technique, which uses a single cell designed to be compatible with nuclear magnetic resonance (NMR) imaging to perform all stages of the experimental cycle from spontaneous imbibition to forced secondary drainage. The use of D2O brine instead of conventional H2O brine enables monitoring of oil saturation changes across the different phases. NMR provides a precise evaluation of saturation variations along the rock sample, enabling the calculation of a far more precise Amott index, as it helps to deal with the presence of capillary end effects. Another benefit is reduced experimental duration due to less handling and the use of viscous sweeping for forced steps. The proof of feasibility of the Amott Express is confirmed by results obtained from a reservoir rock sample. In addition, keeping the same rock inlet throughout the corefloods allows the inlet pressure to be approximated as capillary pressure, which is then associated with inlet-face saturation (evaluated with NMR). This approach provides capillary pressure curves at each step, enabling evaluation of the USBM index. The Amott Express technique offers a practical and reliable solution for obtaining Amott and USBM indices while minimizing errors and uncertainties associated with cell exchange.
Authors: Laurent Rochereau, TotalEnergies, Quentin Danielczick, TotalEnergies, Régis Brugidou, TotalEnergies, Franck Nono, TotalEnergies, Victor Fernandes, TotalEnergies, Benjamin Nicot, TotalEnergies
Language: English
Subfield: Ocean Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6912033308
FWCI:
Cites:
Cited by:
Related to: