Abstract: Wettability alteration of the oil-wet reservoir rocks to the water-wet state is an important factor for enhanced oil recovery (EOR). One of the main challenges of applying nanoparticles for wettability alteration is related to the colloidal stability and poor adsorption of the nanofluids in the harsh conditions of the reservoirs. In the present work, comparative studies were followed between polymer-coated silica nanoparticles by polyethylene glycol (Mn ~ 2000) and amphiphilic polymer-coated silica nanoparticles by polyethylene glycol (Mn ~ 2000 or 5000) and propyl chains to determine wettability alteration and adsorption of these modified nanoparticles on porous media. Water contact angle and UV–Vis adsorption measurements showed which the efficiency of amphiphilic polymer-coated nanoparticles depends on the wettability state of glass and it was improved significantly by oil-wet glass substrates due to the existence of the hydrophobic polymer on the surface of the nanoparticles. Moreover, effective parameters including temperature, and pH were studied. The better performance was obtained for the modified silica nanoparticles by polyethylene glycol (Mn ~ 5000) and propyl chains at 1000 ppm concentration in pH of 6 and the temperature range of 25-55°C. Our study demonstrated amphiphilic polymer-coated silica nanoparticles can be considered as a promising agent which has the potential for EOR purposes.Abstract: Wettability alteration of the oil-wet reservoir rocks to the water-wet state is an important factor for enhanced oil recovery (EOR). One of the main challenges of applying nanoparticles for wettability alteration is related to the colloidal stability and poor adsorption of the nanofluids in the harsh conditions of the reservoirs. In the present wor...Show More
Abstract: The use surfactant chemicals to improve oil recovery has been practiced both at laboratory and field scale levels. The results obtained have revealed an incremental oil recovery with surfactant injection. Surfactant injection aims at reducing the interfacial tension (IFT) between oil-water systems resulting to increase in the microscopic sweep of the reservoir. In this paper, a study was carried out to investigate the potentials of locally sourced surfactants as substitute for imported synthetic surfactants. Four different locally sourced surfactants; PBAS, RPAS, UPAS and SCS alongside two synthetic products were tested. Fourier Transformed Infrared (FTIR) Technique was used to identify the various functional groups present in the samples; presence of C-Br, C-CI, R-O-R, H2C=CH3, RNH2, RCOOR, RCOOH, R2C=O, R-S-C≡N, CH2, R-S-C≡N, R2N and RCHOH were observed. The effects of temperature, surfactant conc., salinity and polymer concentration on IFT reduction of a brine- oil system were investigated in order to evaluate the performance of the samples in reducing interfacial tension. The results obtained from the FTIR test revealed the close similarities in the constituents present in local and synthetic material which makes them good candidates to consider for chemical EOR. This finding was also confirmed by the IFT reduction test conducted.Abstract: The use surfactant chemicals to improve oil recovery has been practiced both at laboratory and field scale levels. The results obtained have revealed an incremental oil recovery with surfactant injection. Surfactant injection aims at reducing the interfacial tension (IFT) between oil-water systems resulting to increase in the microscopic sweep of t...Show More
