Title | Determination of Clay Bound Water in Shales from NMR Signals: The Fractal Theory |
Authors | Liu, Kouqi Jin, Zhijun Zeng, Lianbo Yuan, Yujie Ostadhassan, Mehdi |
Affiliation | China Univ Petr, State Key Lab Petr Resources & Prospecting, Beijing 102249, Peoples R China China Univ Petr, Coll Geosci, Beijing 102249, Peoples R China Yunnan Univ, Sch Earth Sci, Kunming 650500, Yunnan, Peoples R China Northeast Petr Univ, State Key Lab Continental Shale Accumulat & Effic, Minist Educ, Daqing 163318, Peoples R China Peking Univ, Inst Energy, Beijing 100871, Peoples R China |
Keywords | NUCLEAR-MAGNETIC-RESONANCE PORE STRUCTURE GEOCHEMICAL PROPERTIES PERTH BASIN ADSORPTION RESERVOIR ROCKS SEM N-2 |
Issue Date | 18-Nov-2021 |
Publisher | ENERGY & FUELS |
Abstract | Clay bound water (CBW) is an essential parameter to calculate not only water saturation but also other petrophysical parameters in shaly formations. Hence, in order to accurately obtain the information pertaining the CBW, nuclear magnetic resonance (NMR) is commonly used, which is sensitive to hydrogen that is adsorbed by clay minerals. Knowing that temperature can remove CBW, we combined thermal treatment (dehydration of the samples under a series of temperatures), low field NMR in the laboratory, and fractal theory to acquire better insights on how NMR signals can reveal the critical dehydration temperature to determine the CBW. For this purpose, a shale sample is exposed to a series of elevated temperatures and then a NMR transverse relaxation signal T-2 was acquired and analyzed with the fractal theory. The fractal dimensions of the T-2 revealed a sharp decrease as the hydration temperature exceeds a certain critical value. Furthermore, the T-1/T-2 from the 2D NMR map demonstrated that at this critical temperature, the signal intensity representing the hydroxyl group decreases as well, indicating the loss of the absorbed water. Based on the result, we were able to confirm that fractal dimension analysis can reveal the critical hydration temperature to ultimately determine the CBW, most importantly independent of running extra unnecessary experiments to save costs. |
URI | http://hdl.handle.net/20.500.11897/634156 |
ISSN | 0887-0624 |
DOI | 10.1021/acs.energyfuels.1c02285 |
Indexed | SCI(E) |
Appears in Collections: | 待认领 |