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Comparative Study on Enhancing Oil Recovery under High Temperature and High Salinity: Polysaccharides Versus Synthetic Polymer

[Image: see text] The synthetic water-soluble polymer, partially hydrolyzed polyacrylamide (HPAM), has been most widely used for enhanced oil recovery (EOR); however, its poor thermal stability and weak salt tolerance impede further application in high-temperature and high-salinity oil reservoirs. T...

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Detalles Bibliográficos
Autores principales: Liang, Ke, Han, Peihui, Chen, Quansheng, Su, Xin, Feng, Yujun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2019
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6648808/
https://www.ncbi.nlm.nih.gov/pubmed/31460160
http://dx.doi.org/10.1021/acsomega.9b00717
Descripción
Sumario:[Image: see text] The synthetic water-soluble polymer, partially hydrolyzed polyacrylamide (HPAM), has been most widely used for enhanced oil recovery (EOR); however, its poor thermal stability and weak salt tolerance impede further application in high-temperature and high-salinity oil reservoirs. To address such deficiencies, three polysaccharides, xanthan gum, diutan gum, and scleroglucan, were examined in comparison with HPAM on rheological behaviors, shearing resistance, long-term thermal stability, and core flooding test. It was found that all of these three polysaccharides were less sensitive to salinity and shearing time, while HPAM showed a monotonous decrease in viscosity with increasing monovalent cations and shearing history. After 90 days of aging at 85 °C and 10.1 × 10(4) mg·L(–1) of total dissolved solids with 1.0 × 10(3) mg·L(–1) of Ca(2+), the viscosity of diutan gum and scleroglucan solutions nearly remained unchanged; on the contrary, the viscosity of xanthan gum and HPAM solutions drops massively. Core flooding tests at 85 °C with the same initial viscosity demonstrated that all polymers showed good transportation in porous media, and 16, 13, and 11% of oil recovery were obtained by diutan gum, scleroglucan, and xanthan gum, respectively, while only 10% was obtained from HPAM. These comparative results may underpin the potential of diutan gum and scleroglucan to be used in the EOR process in HTHS oil reservoirs.