Asian Journal of Engineering and Applied Technology ISSN: 2249-068X (P) Vol.13 No.2, 2024, pp.1-6 © Centre for Research and Innovation www.crijournals.org DOI: https://doi.org/10.70112/ajeat-2024.13.2.4239 Experimental Investigation of the Suitability of Surfactants Extracted from Plant Leaves for Enhanced Oil Recovery Bright Bariakpoa Kinate*, Godwin Chukwuma Jacob Nmegbu, Samson Wokike and Godloves Tondie Nonju Department of Petroleum Engineering, Rivers State University, Port Harcourt, Nigeria *Corresponding Author: kinate.bariakpoa@gmail.com (Received 3 August 2024; Revised 22 August 2024, Accepted 15 September 2024; Available online 25 September 2024) Abstract - The application of natural surfactants in enhanced oil recovery has recently gained popularity due to their environmentally friendly nature and low cost of production. Several natural surfactants have been extracted from plant leaves and tested for interfacial tension reduction and increased oil recovery. However, it is important to evaluate the oil recovery potential of natural surfactants extracted from plant leaves that are abundant and available in each region for easy production. This study evaluates the recovery potential of surfactants produced from Citrus sinensis leaves, Carica papaya leaves, and Garcinia kola leaves due to their saponin contents for enhanced recovery while reducing the cost of conventional surfactants. The plant leaves (Citrus sinensis, Carica papaya, Garcinia kola) were washed, dried for one week, ground, and measured in quantities of 2 grams and 4 grams. The measured quantities were added to 30 ml of hot water, stirred to mix uniformly, and then brine was added to fill up to 1000 ml in the cylinder. The solution was filtered to obtain the surfactant extract. Core samples were saturated with low salinity brine (10,000 ppm) and flooded with crude oil until irreducible water saturation was achieved. The breakthrough time and volume of water and oil recovered were measured. The brine was replaced with the extracted surfactants at concentrations of 2000 ppm and 4000 ppm, and used for flooding. The volume of oil recovered for each surfactant was measured. The results show that the Citrus sinensis surfactant had an early breakthrough at 28 seconds with 73.68% oil recovery, compared to the 4000 ppm dosage, which had a breakthrough at 34 seconds with 77.5% oil recovery. The Carica papaya surfactant at a 2000 ppm dosage had a breakthrough at 33 seconds with an oil recovery of 85%, and at 39 seconds with an 80.95% recovery for the 4000 ppm dosage. The Garcinia kola surfactant had a late breakthrough at 44 seconds with 76.08% oil recovery for the 2000 ppm dosage and 80.00% recovery at 40 seconds breakthrough for the 4000 ppm dosage. The Carica papaya surfactant provided the highest oil recovery at the lowest dosage of 2000 ppm. Keywords: Natural Surfactants, Oil Recovery, Plant Leaves, Interfacial Tension, Saponin Contents I. INTRODUCTION Flooding with surfactants is one of the most efficient methods for enhancing oil recovery through chemical injection. The need to improve the recovery factor to above 50% to 60% of the original oil in place has arisen, driven by chemical-enhanced methods [1]. This approach displaces crude oil in the void spaces to the producing wells [2], [3]. The primary factors determining the selection and success of flooding with surfactants include the structure, salinity level, surfactant pH value, temperature, rock properties, and adsorption behavior. Surfactants come in various forms proposed for enhanced oil recovery (EOR), including cationic, anionic, nonionic, and natural surfactants. However, the application has focused on natural surfactants as active agents for enhanced oil recovery due to their effectiveness. Surfactant injection into mature oil reservoirs as a chemical approach for EOR has proven promising and effective [4], [5]. Surfactants have been shown to decrease interfacial tension, modify fluid-to-fluid and rock-to-fluid interactions, and increase production [6], [7]. Many natural surfactants have been extracted from various plant parts such as flowers, roots, leaves, seeds, and oils, and have demonstrated the ability to reduce interfacial tension and improve recovery [8], [9], [10]. Additionally, animal and plant oils such as sesame oil, coconut oil, and linseed oil have been processed into natural surfactants for enhanced oil recovery and have shown good performance [11], [12], [13]. For instance, A.B. Chhetri et al., [14] extracted surfactants from the shell pericarp of Mukurossi sapindus fruit to decrease the interfacial tension (IFT) between oil and water, achieving over a 30% reduction. Similarly, natural surfactants derived from Seidlitzia rosea and Rosemary plants were used to decrease interfacial tension and increase oil recovery, resulting in an improved recovery factor [15]. Surfactants extracted from Ziziphus spina-christi plant leaves were utilized for EOR flooding in a carbonate reservoir, recording a significant increase in oil recovery [16]. Likewise, S. Kumar et al., [17] investigated the suitability of Glycyrrhizin glabra and Mulberry leaf surfactant extracts in carbonate reservoirs, achieving an improved oil recovery of 17.8% and 34% of the original oil in place. Cedar- derived surfactants produced from mulberry tree leaves were used to alter wettability in carbonate and sandstone rocks, reducing the interfacial tension between water and kerosene from 44 to 17.9 mN/m [18]. Surfactant extracts from Matricaria chamomilla plants were tested for interfacial tension reduction with kerosene as the oil phase and distilled water, showing a decrease from 30.6 to 12.67 mN/m [19]. A. Khorram Ghahfarokhi et al., [20] evaluated surfactants extracted from Prosopis leaves to reduce the 1 AJEAT Vol.13 No.2 July-December 2024