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Prince Julius ¹, P. N. Ananthanarayanan ¹, M. Gopikrishnan ¹, M. Thirumavalavan ²

Affiliations
1 Department of Petroleum Engineering, Amet University, Chennai, IN
2 Department of Mechanical Engineering, Bharath University, Chennai, IN

Abstract

Surfactants play an important role to alter wettability in any reservoir. Adsorption of surfactants onto reservoir surface will reduce the contact between water and oil which indeed has less impact on Interfacial tension. Oil wet reservoirs are specifically preferred than water wet due to high oil saturation. At the same time extracting oil from oil wet reservoir is difficult due to its wetting nature. The only way to extract oil is by altering wettability from oil wet. The aim of this work is to extract more oil with less adsorption by altering oil wet to surfactant wet. Wettability of sandstone has been chosen to alter from oil wet to surfactant wet. Surfactants of low concentration, which is less than CMC (Critical Micelle Concentration) has been introduced before surfactant flooding during water flooding to make core surfactant wet. The recovery of oil during water flooding is 0.2 Pore Volume (PV). This has been increased to 0.5 pore volume by making it surfactant wet and adsorption has been reduced to 0.5 pore volumes.

Keywords

Adsorption, CMC, Surfactant Wet, Wettability

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Prince Julius ¹, P. N. Ananthanarayanan ¹, Sri Devi ²

Affiliations
1 Department of Petroleum Engineering, Amet University, Chennai-603112, IN
2 Department of Mechatronics, Bharath University, Chennai, IN

Abstract

Alteration of wettability for a carbonate reservoir is one of the complex challenges faced by petroleum engineers. Cationic surfactants are the only surface agents which have shown successful results with minor exceptions. Recently, surfactant blends has shown ability to posses stability at high temperatures with low Critical Micelle Concentration (CMC). The aim of this research work is to compare the ability of Cationic nonionic blends with cationic surfactants for improving recovery in carbonate reservoirs. The surfactant blends were chosen to alter wettability for a Carbonate core is Cetyltri Alkyl Bromide (CTAB) with Ethoxcylated Alcohol (EO). The concentration of cationic surfactant CTAB was selected based on Krafts point and for nonionic EO on phase separation process. The results were observed on core flooding apparatus. Surfactant blend has shown 0.75 pv (pore volume) of recovery with 2 pv of injection and CTAB of 0.55 pv with 3 pv injection

Keywords

Adsorption, Cationic Surfactant, CMC, Krafts Point, Nonionic Surfactant, Surfactants Blends, Wettability

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Prince Julius ¹, P. N. Ananthanarayanan ¹, V. Srinivasan ¹

Affiliations
1 Department of Petroleum Engineering, AMET University, Chennai, 603112, IN

Abstract

Adsorption of surfactants on sandstones leads to reduce in recovery efficiency of oil. This is caused mainly because of clay presence. Most of the water flooding projects has been stopped, when clay is present. Even surfactants are adsorbed due to clay. The aim of this research work is to reduce the adsorption of surfactants for different pH clay mixed sandstones. Three clay sandstones as crushed samples with different pH levels have been tested to observe the adsorption of Anionic surfactants Sodium Dodecyl Sulphonate (SDS) through bottle test. There was no significant adsorption found on pH 3 and above. Adsorption of SDS on pH 2 clay sandstone has reduced due to increase in alkalinity by application of Sodium Carbonate (Na2CO3).

Keywords

Adsorption, Clay Sandstone, Surfactants, SDS, Wettability

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Prince Julius ¹, P. N. Ananthanarayanan ¹, G. Anbazhagan ¹

Affiliations
1 Department of Petroleum Engineering, Amet University, Chennai - 603112, Tamil Nadu, IN

Abstract

Wettability of a reservoir rock is closely related to capillary pressure curves. The status of wettability is an important factor for oil recovery, can be clearly seen through the variations in capillary pressure curves. The aim is to analyze the changes in capillary pressure curves and saturations by altering wettability. An oil wet core sample was tested to alter wettability. During alteration process it is difficult to analyze the status of wettability. Surfactants were applied to modify wettability. Additionally, parameters like connate water saturation, spontaneous oil and water saturations, residual oil saturation and type of wettability can be analyzed. The concentration of surfactants was selected by conductivity test. The changes in saturations with variations in capillary pressure curves were stated.

Keywords

Adsorption Anionic Surfactant, Capillary Pressure Curves, CMC, Wettability

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