Injection of alkaline (A), polymer (P), and surfactant (S) chemicals in enhanced oil recovery (cEOR) processes increases output by changing the properties of the injected fluid. In this work, micellar fluid interactions were studied via microemulsion rheological analysis. Crude oil and stimulated brine with ASP or SP was used for bottle testing. The results revealed that no microemulsion was produced when ASP (Alkaline, Surfactant, and Polymer) or SP (Surfactant and Polymer) was left out during the bottle testing phase. The addition of ASP and SP led to the formation of microemulsions—up to 29% for 50% water cut (WC) ASP, and 36% for 40% WC SP. This shows that the addition of ASP and SP can be applied to flooding applications. The results of the rheological analysis show that the microemulsions behaved as a shear-thinning micellar fluid by decreasing viscosity with increase in shear rate. As per the power-law equation, the ASP micellar fluid viscoelastic behavior shows better shear-thinning compared to SP, suggesting more efficiency in fluid mobility and sweep efficiency. Most of the microemulsions exhibited viscoelastic fluid behavior (G’ = G”) at angular frequency of 10 to 60 rad s−1, and stable elastic fluid behavior (G’ > G’’) below 10 rad s−1 angular frequency. The viscosity of microemulsion fluids decreases as temperature increases; this indicates that the crude oil (i.e., alkanes) was solubilized in core micelles, leading to radial growth in the cylindrical part of the wormlike micelles, and resulting in a drop in end-cap energy and micelle length. No significant difference was found in the analysis of viscoelasticity evaluation and viscosity analysis for both ASP and SP microemulsions. The microemulsion tendency test and rheology test show that the addition of ASP and SP in the oil-water interface yields excellent viscoelastic properties.

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The formation of foam due to the injection of surfactant foam in FAWAG causes significant problems in the oil well production and separation facilities. The excessive foam can lead to the reduction of the separator capacity as well as its efficiency. A defoamer is needed to break and destroy the foam in the separator. There are many commercially available defoamer agents in the market, but not all defoamers are suitable for every application. For this reason, four modified silicone-based defoamers were successfully synthesized and characterized based on the data obtained from the screening process using various commercial defoamers. The performance of modified defoamers was evaluated using TECLIS FoamScan that imitate real conditions of treatment. The results show that all four of the modified silicone-based defoamers, especially amide-terminated-modified defoamers (S2) showed excellent performance as a defoaming agent to mitigate foam in specific conditions. The best-case condition for the modified defoamer to perform was at a high temperature (60 °C), gas flow rate of 1.0 L/min, and low ration concentration of the surfactant to brine (30:70). The study on the bubble count and distribution using a KRÜSS Dynamic Foam Analyzer revealed that S2 excellently contributes to the formation of unstable foam that can fasten foam destruction in the foaming system.

The studies involves several unique case for EOR fields in which crude oil samples were collected from from peninsular Malaysia and Borneo. These fields has different reservoir characteristic in pressure, temperature and gas composition. Five Crude Oil from EOR field were undergone Naphthenate acid extraction using acid IER techniques for further instrument analysis to classification of Naphthenate acid type's component. Comparison of soaps-microemulsion generated was then analyse using static bottle test and Naphthenates/Emulsions Flow Rig Tests. The findings shows the Malaysian crude oil is able to be classified by type of naphthenate acid which are mono-protic acid generating sodium carboxylate soap and tetraprotic acid known as ARN which leads to calcium naphthenate deposit. There are fields that located nearby each other has different characterization of crude and types of acids which leads to different type and severities of soaps-microemulsion and soaps-fines foams formation from apllied EOR chemical. Statics bottle test at higher water cuts shows significant differences with observation from Naphthenates/Emulsions Flow Rig Tests. From this paper classification of Naphthenate acid for Malaysian crude oil has been established with its behavior to induce Soaps-Microemulsion and Soap-Fines Foam in Malaysian EOR Fields using more representive method by Naphthenates/Emulsions Flow Rig Tests.