Simulation Investigation of Hybrid Surfactant and Engineered Water Injections to Improve Oil Recovery from Carbonates

  • Ahmed Adila

    Student thesis: Master's Thesis

    Abstract

    As global energy demand increases, the need to maximize oil recovery from current mature reservoirs has become crucial. Therefore, different enhanced oil recovery (EOR) techniques have been proposed. Chemical enhanced oil recovery (CEOR) has been considered among the most promising techniques because of its higher efficiency and reasonable economic feasibility. Surfactant flooding is a well-established and commercially-available CEOR technique in the petroleum industry. Engineered water injection (EWI) is also another EOR technique that has gained popularity as an effective and promising technique. The hybrid effect of combining surfactant and EWI is expected to increase oil recovery and improve sweep efficiency compared to surfactant flooding or EWI alone. The objective of this research is to investigate the hybrid effect of surfactant and EWI on oil recovery from carbonates under harsh conditions of temperature and salinity. The computer modeling group simulator CMG-GEMTM was utilized in this work. A 2D surfactant flooding model was created and validated by history-matching recently conducted surfactant coreflooding experiments. Oil recovery, pressure drop, and surfactant concentration data were utilized. The surfactant flooding model was then coupled with a geochemical model that captures different reactions during EWI. Also, different simulation scenarios were considered in this work including waterflooding, surfactant flooding, EWI, and hybrid surfactant-EWI. Sensitivity analysis on the hybrid process was also performed including surfactant adsorption, concentration, and microemulsion viscosity as well as water composition. The results showed that hybrid surfactant-EWI is a promising technique for oil recovery from carbonates under harsh conditions. In hybrid surfactant-EWI, wettability alteration is the controlling mechanism where surfactant boosts oil recovery rate through increasing oil relative permeability while EWI reduces residual oil. Nevertheless, this more water-wetting rock state leads to lower well injectivity. This work gives more insight into the application of hybrid surfactant-engineered water injection on enhancing oil recovery from carbonates.
    Date of AwardDec 2020
    Original languageAmerican English

    Keywords

    • Surfactant Flooding
    • Engineered Water Injection
    • Hybrid EOR
    • Carbonate Reservoirs
    • Harsh Conditions.

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