The Effect of Polymer on Triglyceride Microemulsion Formulation for Tertiary Oil Recovery

This paper presents the effect of polymer on the rheological properties of triglyceride microemulsions. Non-Newtonian shear thinning behavior of triglyceride microemulsions has been modeled satisfactorily using a power law. It was observed that the effects of surfactant and cosurfactant concentrations on the apparent viscosity are significant. However, the effect of salinity on the same viscosity is very trivial. Viscosities of the tested samples have shown a tendency to increase significantly with the addition of xanthan gum (high molecular weight exocellular polysaccharide). The increase is affected by the function of temperature and polymer concentrations, mainly influencing the terminal relaxation time of the solutions. This way, the optimum polymer concentration, 1500 ppm, was obtained on the basis of the performance of the optimum thickened triglyceride microemulsion in tertiary oil recovery at various temperatures and polymer concentrations

Pre-prepared Microemulsion Flooding in Enhanced Oil Recovery: A Review

It is evident that one of the important applications of microemulsions is in enhanced oil recovery (EOR) process due to its unique properties such as ultra-low interfacial tension. The injection of microemulsion slug reduces the interfacial tension between the crude oil and reservoir brine, which leads to mobilization of substantial fraction of residual oil. In general microemulsion flooding is classified into two distinct categories, pre-prepared and in situ prepared, depending on its preparation method. The authors present a detailed discussion of microemulsion preparation and summarizes major articles on pre-prepared microemulsion flooding in EOR processes. Their review opens new horizons for the future researches on pre-prepared microemulsion flooding in EOR processes by organizing the literature data and comparing them

Correlations between interfacial tension and cumulative tertiary oil recovery in a triglyceride microemulsion flooding

This paper presents measurements of interfacial tension (IFT) and tertiary oil recovery (TOR) of triglyceride microemulsion flooding over a wide range of aqueous phase compositions. Based on 160 experimental data sets, two empirical correlations were established. Both the power-law and logarithmic models were validated statistically. Power-law and logarithmic models are predicted to perform best at ultralow IFT range (2 mN/m), respectively. The valid models indicate that IFT is the sole parameter affecting the cumulative TOR in a triglyceride microemulsion flooding. This phenomenon, however, does not apply in hydrocarbon-based microemulsions

In Situ Prepared Microemulsion-polymer Flooding in Enhanced Oil Recovery—A Review

Microemulsion could be formed in situ through simultaneous injection of surfactant, cosurfactant, and brine into the reservoir. The formed microemulsion is expected to propagate toward the production well and along its way sweep significant amounts of the remaining hydrocarbon in the reservoir. There are numerous reports on in situ prepared microemulsion flooding in the literature. The interest in in situ prepared microemulsion flooding research activities is expected to increase tremendously in the near future because of its high potential in maximizing hydrocarbon recovery in enhanced oil recovery activities. The authors summarize major articles relevant to in situ prepared microemulsion flooding with application of various polymers in the flooding. They also discuss critically and extensively the effect and function of polymers and their role in the microemulsion flooding. This review opens new horizons for future research on in situ prepared microemulsion-polymer flooding in enhanced oil recovery processes by systematically organizing and comparing data in the literature. The data and information presented would be very useful to researchers conducting work related to enhanced oil recovery with microemulsion polymer flooding

Formulation and phase behavior study of a nonionic triglyceride microemulsion to increase hydrocarbon production

It is no secret that during microemulsion flooding, the oil entrapped in rock pores can be easily removed when a new Winsor Type III microemulsion is formed in situ. Formulation of an efficient microemulsion in tertiary oil recovery requires good understanding of its phase behavior. This paper presents the phase behavior study of a triglyceride microemulsion before and after n-octane solubilization in formulating an efficient triglyceride microemulsion. The effects of solubilized oil as co-oil, salinity, surfactant concentration and co-surfactant concentration on the phase behavior of a triglyceride microemulsion were investigated. The optimized aqueous phase composition of the triglyceride microemulsion was adjusted at 1 wt% alkyl polyglycosides, 3 wt% glyceryl monooleate, 3 wt% sodium chloride, and 93 wt% de-ionized water. It is concluded that this condition represents the widest range and the maximum volume of Winsor Type III microemulsion that can be achieved for the triglyceride microemulsion after fluid injection

Formulation, optimization and application of triglyceride microemulsion in enhanced oil recovery

This paper presents the determination of an aqueous phase composition of a new triglyceride microemulsion in which the triglycerides constitute the whole oil-phase of the microemulsion. Palm oil was used as the oil phase of the microemulsion. Experimental results indicate that the optimum triglyceride microemulsion was achieved when equal mass of palm oil and the aqueous phase containing 3 wt% sodium chloride, 1 wt% alkyl polyglycosides, 3 wt% glyceryl monooleate, and 93 wt% de-ionized water were mixed. The formulated composition of the aqueous phase was able to form translucent Winsor Type I microemulsion with palm oil at ambient conditions. The measured interfacial tension between the optimum microemulsion and the model oil, which is n-octane in this study, was 0.0002 mN/m. The maximum tertiary oil recovery of 71.8% was achieved after the injection of the optimum microemulsion formulation to a sand pack. The significant increase in total oil recovery (87%) suggests the effectiveness of the triglyceride microemulsion formulation for enhanced oil recovery. Its capability in recovering additional oil (4.3% of the trapped oil after water flooding) compared to a typical polymer in tertiary oil recovery indicates the efficiency of the optimum triglyceride microemulsion formulation

Prediction of the optimum aqueous phase composition of a triglyceride microemulsion using response surface methodology

This paper presents the application of response surface methodology to predict the optimum aqueous phase composition of a triglyceride microemulsion for enhanced oil recovery. The two models capturing the relationships between interfacial tension and tertiary oil recovery data with the aqueous phase composition were validated prior to optimization. It was predicted that the optimum aqueous phase contains 3 wt% sodium chloride, 0.98 wt% alkyl polyglycosides, and 2.98 wt% glyceryl monooleate. At this composition the corresponding interfacial tension is minimum (0.000229451 mN/m) and the tertiary oil recovery is maximum (71.7865%). The predicted optimum aqueous phase composition using historical-data design is close to the experimental value

Prediction of Phase-Inversion Temperature of a Triglyceride Microemulsion Using Design of Experiments

This paper presents the estimation of phase inversion temperature (PIT) of a nonionic microemulsion by studying its interfacial tension (IFT) as a function of temperature. In this work, one-factor design (OFD), which is an approach of Design of Experiments (DOE), was used to model the variation of IFT with temperature. A transformed quadratic equation with lambda of 0.87 was then fitted and validated. The model was optimized to predict the PIT, the temperature at which the IFT is a minimum. The IFT from the optimization of the model at the predicted PIT of 44.43 °C is 0.000154709 mN/m. The value shows an excellent agreement with the experimental value (0.00018 mN/m). Therefore, DOE is capable of predicting the PIT of a microemulsion with high accuracy using only seven design points