Petroleum Engineering – Reservoir
Seyed Reza Shadizadeh; Amin Derakhshan
Abstract
Oil recovery from oil wet carbonate rock is a big challenge in oil industry. In the present study, the influence of natural surfactant Hawthorn leaves extract (HLE) on oil recovery from carbonate rock is investigated. Two chemical surfactants include Sodium dodecyl sulfate (SDS) and Dodecyl tri methyl ...
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Oil recovery from oil wet carbonate rock is a big challenge in oil industry. In the present study, the influence of natural surfactant Hawthorn leaves extract (HLE) on oil recovery from carbonate rock is investigated. Two chemical surfactants include Sodium dodecyl sulfate (SDS) and Dodecyl tri methyl ammonium bromide (DTAB) were used for validation and comparison oil recovery with new natural surfactant HLE. Wettability alteration test using contact angle method, interfacial test (IFT) using pendant drop and core flooding were employed to investigate the behavior of the surfactants on oil recovery. Experimental results show the Critical Micellar Consentration (CMC) point of different concentrations of HLE, SDS and DTAB solution occurred at 3.25, 3 and 4.06 wt. %, respectively. The natural surfactant HLE was more effective than other chemical surfactant (SDS and DTAB) at CMC point in wettability alteration. As observed the contact angle of carbonate pellet and the HLE at CMC point was 86 degrees and this angle for SDS and DTAB were 112 and 92 degrees, respectively. Core flooding results show that oil recovery factor was improved from 37% with water flooding to 47.6 with SDS; 56.2% with DTAB and 54.7% with HLE. The results prove that; this new natural surfactant (HLE) can be used as a novel surfactant for chemical enhanced oil recovery process in carbonate oil reservoirs. HLE has beneficial effects in oil recovery because of its environment friendly compare to SDS and DTAB.
Mohsen Seid Mohammadi; Jamshid Moghadasi; Amin Kordestany
Abstract
Wettability alteration is an important method for increasing oil recovery from oil-wet carbonate reservoirs. Chemical agents like surfactants are known as wettability modifiers in carbonate systems. Oil can be recovered from initially oil-wet carbonate reservoirs by wettability alteration from oil-wet ...
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Wettability alteration is an important method for increasing oil recovery from oil-wet carbonate reservoirs. Chemical agents like surfactants are known as wettability modifiers in carbonate systems. Oil can be recovered from initially oil-wet carbonate reservoirs by wettability alteration from oil-wet to water-wet condition with adding dilute surfactant and electrolyte solutions. This paper investigates the effects of brine concentration, surfactant concentration, and the pH of injection water on the wettability alteration of carbonate reservoirs by different class of surfactants. Scanning electron microscopy images verified the formation of surfactant layer surfaces and the adsorption of surfactant molecules on the rock. The results revealed that TX-100, as a nonionic surfactant, and CTAB, as a cationic surfactant, were better wettability modifiers than SDS, as an anionic surfactant, for carbonate rocks. At the concentration of 1 wt.% and higher, the contact angle reduction was approximately unchanged. The results also proved that there was an optimum salinity for the maximum wettability alteration by surfactants. Increasing the pH of aging fluid resulted in better wettability alteration by CTAB, while, in the case of SDS, the wettability alteration was reduced. Acidic conditions had a negligible effect on the wetting behavior of TX-100.
