Will Coupling Low Salinity Water and Steam Flooding for Heavy Oil Affect the Rock Properties of Sandstone Reservoirs? An Experimental and Simulation Study
Recently Al-Saedi and Flori et al. (2018d) studied the potential of low salinity alternating steam flooding (LSASF) in laboratory sandstone cores, and the results were promising for increasing heavy oil recovery. In this study, we investigate the effect of LSASF on rock properties for the Bartlesville Sandstone Reservoir. These core samples contain high viscous oil (600 cp) with an average permeability of 80 mD. Combining low salinity (LS) water flooding and steam flooding is a novel idea that takes advantage of the relative strengths of both methods. To investigate the proposed new method and the role of LSASF, core flooding experiments, contact angle measurements, spontaneous imbibition tests, zeta potential tests, and reactive transport model were performed. The laboratory experiments showed that optimum recovery is achieved by diluting the FW 40 times and using the same water in a shorter steam cycle. Permeability measurements before and after core flooding revealed that the higher the salinity, the more permeability decreased. Steam can enhance the performance of LS water by reducing precipitation, increasing permeability, and dissolving minerals, and in turn, increasing oil recovery. Flooding the core with both LS water and steam resulted in more water wetness in the sandstone cores. Comparing the cores that were flooded with only LS water with the cores flooded with both LS water and steam, lower water wetness was obtained for the cores that were flooded only with LS water. The results were deliberated concerning wettability change processes by LS Water and steam. The zeta potential tests confirmed that as the salinity decreases, the zeta potential decreases too. Also, measuring contact angle before and after core flooding resulted in more water wetness. Spontaneous imbibition tests were in line with all other tests. The reactive transport modeling confirmed the crucial role of diluting FW in decreasing the number of the most effective kaolinite edges Si—O-- and Al--O--, which explains why lowering the salinity gives additional oil recovery.
H. N. Al-Saedi et al., "Will Coupling Low Salinity Water and Steam Flooding for Heavy Oil Affect the Rock Properties of Sandstone Reservoirs? An Experimental and Simulation Study," Journal of Molecular Liquids, vol. 306, Elsevier, May 2020.
The definitive version is available at https://doi.org/10.1016/j.molliq.2020.112866
Geosciences and Geological and Petroleum Engineering
Keywords and Phrases
Average permeability; Laboratory experiments; Low-salinity water; Permeability measurements; Reactive transport modeling; Sandstone reservoirs; Simulation studies; Spontaneous imbibition
International Standard Serial Number (ISSN)
Article - Journal
© 2020 Elsevier, All rights reserved.
15 May 2020