Article
Chemistry, Physical
Ehsan Pooryousefy, Quan Xie, Yongqiang Chen, Colin D. Wood, Ali Saeedi, Ahmad Sari
Summary: This study reveals the dependence of wettability of high base number oil on factors such as water pH, ion type, and salinity. It highlights that pH plays a major role in wettability, while salinity and ion type play a secondary role.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Engineering, Chemical
Xiong Liu, Le Yan, Qian Gao, Yafei Liu, Hai Huang, Shun Liu
Summary: Fracture network fracturing combined with oil-water infiltration and replacement is an effective approach to develop tight sandstone reservoirs. This study focuses on the CHANG-7 tight sandstone reservoir in the Changqing oilfield of CNPC and investigates the mechanisms and quantitative characterization of salinity's influence on imbibition oil recovery. The results show that salinity mainly affects the imbibition process through reducing oil-water interfacial tension and constructing an osmotic pressure displacement model. The influence of salinity on interfacial tension can be significant, and it becomes more pronounced with higher differences in salt concentration.
Article
Energy & Fuels
Ranjan Phukan, Rahul Saha
Summary: A low salinity surfactant (LSS) system was developed to enhance the performance of immiscible surfactant alternating gas/CO2 (SAG) flooding in sandstone reservoir cores. LSS solutions showed positive impacts on various mechanisms responsible for enhanced oil recovery (EOR), including reducing surface and interfacial tension, altering wettability, improving CO2-foam stability, and decreasing surfactant adsorption.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Prashant Jadhawar, Motaz Saeed
Summary: This work models the flooding processes of low salinity waterflooding and low salinity polymer flooding in sandstone reservoirs at nano-and macro-scales. It utilizes triple-layer surface complexation models to simulate interactions at the oil-brine and sandstone-brine interfaces, and applies the DLVO theory to describe the stability of interfacial films. The study proposes the use of the maximum energy barrier as an upscaling and interpolant parameter to adjust relative permeability curves, and uses numerical simulations to evaluate the performance of the flooding processes in sandstone reservoirs. The results show that low salinity polymer flooding gives higher oil recovery compared to standard polymer flooding due to its utilization of wettability alteration and improved mobility control.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Dao-Yi Zhu, Yu-Heng Zhao, Hong -Jun Zhang, Qi Zhao, Chen-Yang Shi, Jun -Hui Qin, Zheng-Hao Su, Gui-Qi Wang, Yang Liu, Ji-Rui Hou
Summary: This study investigated the oil recovery mechanism of a combined imbibition system composed of black nanosheets (BN) and low-salinity water (LSW) in the Jimusar Oilfield. The results showed that the combined system had better emulsification effects on crude oil, altered the wettability of the core surface, increased the imbibition rate, and improved the ultimate oil recovery. The addition of black nanosheets also improved the microscopic sweep efficiency by diverting more fluid into small pores, as indicated by the nuclear magnetic T2 spectrum.
Article
Energy & Fuels
Rukuan Chai, Yuetian Liu, Liang Xue, Zhenhua Rui, Ruicheng Zhao, Jingru Wang
Summary: Formation damage is a common phenomenon in the injection of decreased salinity water in sandstone geothermal reservoirs. It is characterized by a decrease in permeability, shrinkage of pore-throat, and enhancement of water-wettability. The damage is mainly caused by fine migration and mineral dissolution, which decrease the connectivity of porous media and impede water flow.
Article
Energy & Fuels
Motaz Saeed, Prashant Jadhawar, Subhash C. Ayirala, Rockey Abhishek, Yingfang Zhou
Summary: Low salinity waterflooding shows potential in increasing oil recovery compared to regular waterflooding. The interaction between crude oil-brine-rock (COBR) determines the wettability alteration during low salinity waterflooding. Triple-layer surface complexation modelling (TLM) is used to simulate the COBR interactions, while the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory characterizes the COBR stability. The maximum energy barrier (MEB) parameter is proposed as an indicator of reservoir wettability and is correlated with experimentally measured contact angles.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Mathematics, Interdisciplinary Applications
Jinsui Wu, Ciyuan Zhang, Boming Yu, Shangxian Yin, Min Xing, Xuexi Chen, Huiqing Lian, Sihai Yi
Summary: This study investigates the micro-structure of sandstone samples using digital core technology and fractal theory. The fractal characteristics of the pore and solid phases are analyzed, and the relationships between porosity, pore size, particle size, and fractal dimensions are explored. The results show that the solid phase follows a fractal distribution, while the pore phase does not. The study also highlights the significant impact of minimum and maximum pore and particle sizes and magnification on the results. Additionally, the permeabilities of the samples are calculated using the Ergun-Wu equation with the introduction of diameter and mean hydraulic radius.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2022)
Article
Engineering, Chemical
Felipe de O. Apolinario, Adolfo P. Pires
Summary: Low salinity waterflooding involves injecting water with lower salt concentration than the connate water. The pH and the amount of dissolved cations in the water affect cation exchange and residual oil mobilization. This study presents a solution for low salinity slug injection using seawater, considering three dissolved cations and pH effects. The solution shows that pH effects occur near the injection point due to high adsorption rate and creates small regions with salinity changes. The appearance of water and oil banks along the flooding is important for the design of chemical enhanced oil recovery techniques.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Chemistry, Physical
Rohit Kumar Saw, Anshuman Singh, Neetish Kumar Maurya, Ajay Mandal
Summary: Low salinity water flooding is cost-effective and environmentally friendly, and the addition of nanoparticles and polymers can significantly increase oil recovery. The viscosity of complex chemical slugs can be increased by adding nanoparticles to polymer solutions. Low salinity water requires a lower concentration of polymer to reach the target viscosity compared to high saline formation water. The addition of nanoparticles reduces interfacial tension and contact angle, leading to higher oil recovery in low salinity water. Injection of low salinity water-based complex fluid results in incremental recovery of OOIP compared to low salinity water and conventional formation water flooding.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Energy & Fuels
Guangwei Ren, Quoc P. Nguyen
Summary: The low-tension gas (LTG) technique combines oil desaturation by microemulsion and mobility control via foam, offering a promising alternative for tertiary recovery in challenging conditions. Experimental results demonstrate that higher pressure and solubilized methane have limited impacts on current microemulsion behaviors, with surfactant retention at 0.162 mg/g and consistently high oil recoveries around 90% regardless of gas type or oil condition. These findings support the field implementation of LTG for enhanced oil recovery and greenhouse gas utilization.
Article
Energy & Fuels
Priyadarshini Bhicajee, L. Romero-Zeron
Summary: Low salinity waterflooding (LSW) is a promising enhanced oil recovery process that alters the wettability of rocks to improve production. This study evaluated the effect of different flooding schemes on LSW performance and identified multi-component ionic exchange as the dominant mechanism for wettability alteration during the recovery of heavy oil from unconsolidated sands.
Article
Chemistry, Physical
Mehdi Ghasemi, Ali Shafiei
Summary: This paper used Molecular Dynamics (MD) simulation technique to investigate the effect of anionic components of brine solution on intermolecular interactions at the montmorillonite-brine interface. The results showed that SO(4)(2-) anions formed aggregations with Na' cations, while Cl(-) anions were uniformly distributed on the clay surface. The strong affinity of SO(4)(2-) towards Na' reduced hydration possibilities and hindered oil diffusion towards the surface. Additionally, the anionic components of brine solution had no effect on the expansion of the electrical double layer.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Energy & Fuels
Vikas Agrawal, Dhwiti Patel, Shubham Nalawade, Soumitra Nande, Samarth D. Patwardhan
Summary: Low salinity Waterflooding (LSWF) is an effective technique for enhanced oil recovery (EOR), with potential improvements of 5-38% in oil recovery. This study used a commercial reservoir simulator to model the comparison between Sea waterflooding (SWF) and LSWF, and investigated the mechanisms responsible for the incremental oil recovery due to LSWF. A critical parametric study concluded that LSWF is a cost-effective and environmentally friendly method for additional oil recovery in sandstone reservoirs.
PETROLEUM SCIENCE AND TECHNOLOGY
(2023)
Article
Energy & Fuels
Oualid M' Barki, Sean Brame, Orlando Castellanos Diaz, Amit Katiyar, Matt Crosley, Troy Knight, Quoc P. Nguyen
Summary: The study found that the clay content of the rock has a critical impact on the efficiency of the foaming surfactant at high temperature, and there is a strong correlation between permeability, aspect ratio and foam apparent viscosity at steady-state. Therefore, the mineralogy and microstructure of natural sandstone reservoirs play a crucial role in the successful design of a steam foam process.