Investigation of rock and fluid interactions during engineered water flooding in dolomite reservoir rocks

Safavi, M. S ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1080/15567036.2020.1734690
  3. Publisher: Taylor and Francis Inc , 2020
  4. Abstract:
  5. Engineered water (EW) flooding is one of the enhanced oil recovery (EOR) techniques in carbonate reservoirs. In this method, the wettability of reservoir rock is altered by controlling the amount of various ions in the injected brine. The thermodynamics of wettability is related to the surface interactions and stability of water film on a rock surface. It can be identified by calculating disjoining pressure isotherms. In this study, core flooding tests, contact angle and zeta potential measurements along with the disjoining pressure isotherm calculation by the DLVO theory were used to investigate the wettability alteration of dolomite rock. Four brines include reservoir formation water (RFW), sea water (SW) and two engineered water (LSW1 and LSW2) were used as injected fluid. The results show that the ionic strength of the dolomite rock depends on the electrical charge at the brine-rock-crude oil interfaces, as, the presence of divalent ions such as SO4 2- in injected brine led to the repulsive interaction of rock-brine and brine-crude oil interfaces. Also, the disjoining pressure isotherms indicate the water film thickness on the dolomite rock surfaces was increased by using the sea water and two engineered water. This thickness at the LSW2 is about 1.6 times thicker than the LSW1, while in comparison to the SW, the thickness of the film is almost 2 times higher than. Based on the results, the double-layer expansion (DLE) is a mechanistic mechanism in which the wettability alteration of the dolomite rocks. © 2020, © 2020 Taylor & Francis Group, LLC
  6. Keywords:
  7. Disjoining pressure ; DLVO theory ; Dolomite rock ; Engineered water flooding ; Thermodynamic of wettability ; Contact angle ; Crude oil ; Enhanced recovery ; Floods ; Ionic strength ; Isotherms ; Petroleum reservoirs ; Reservoirs (water) ; Rocks ; Seawater ; Wetting ; Disjoining pressure isotherms ; Disjoining pressures ; Dolomite rocks ; Enhanced oil recovery ; Repulsive interactions ; Wettability alteration ; Zeta potential measurements ; Oil well flooding
  8. Source: Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; 2020
  9. URL: https://www.tandfonline.com/doi/abs/10.1080/15567036.2020.1734690?journalCode=ueso20