Petroleum Engineering
Bardiya Yazdani; Amir Hossein Saeedi Dehaghani
Abstract
This research purpose is to investigate the effect of microwaves on the physical and chemical properties of heavy crude oil, in the presence of different minerals. In this regard, the physical and chemical changes of the oil and rock powder (sand and carbonate) mixture have been investigated by microwave ...
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This research purpose is to investigate the effect of microwaves on the physical and chemical properties of heavy crude oil, in the presence of different minerals. In this regard, the physical and chemical changes of the oil and rock powder (sand and carbonate) mixture have been investigated by microwave radiation. Viscosity and temperature changes of two samples have been measured. IP143 and elemental analysis (Carbon, Hydrogen, Nitrogen, and Sulfur) were used to extract and identify the composition changes of asphaltene, respectively. Based on the viscosity and temperature changes, it was found that for both samples at the beginning of microwave radiation there was a decrease in viscosity as a result of heavy hydrocarbon particles cracking, such as asphaltene, and converting them into lighter ones. By continuing the radiation and temperature increase, light compounds started to evaporate; finally, the increase in viscosity was observed. The evaporation process in the sample containing carbonate powder started earlier than the sand powder. From elemental analysis, it was concluded that the sulfur and nitrogen in asphaltene have decreased almost the same for both samples, and this decrease is more evident for sulfur, so the rock powder combined with oil did not have a significant effect on the reduction of these elements. The increase in IFT was also observed due to the evaporation of light oil compounds, and due to the higher temperature of the sample containing carbonate rock powder, more IFT increases have been observed.
Hadi Zolfaghari; Alireza Zebarjadi; Omid Shahrokhi; Mohammad Hosein Ghazanfari
Abstract
Several studies have shown that oil recovery significantly increased by low salinity water flooding (LSWF) in sandstones. However, mechanism of oil recovery improvement is still controversial. CO2 that develops buffer in presence of water is expected as a deterrent factor in LSWF efficiency based on ...
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Several studies have shown that oil recovery significantly increased by low salinity water flooding (LSWF) in sandstones. However, mechanism of oil recovery improvement is still controversial. CO2 that develops buffer in presence of water is expected as a deterrent factor in LSWF efficiency based on mechanism of IFT reduction due to pH uprising. No bright evidence in literature supports this idea. Here, a set of core floods including a pair of CO2 WAG and a pair of water injection tests are conducted and, the efficiency of LSWF and high salinity water flooding (HSWF) were compared for each pair. HSWF was followed by LSWF in tertiary mode. Results showed that not only CO2 does not deteriorate LSWF recovery efficiency, but also improves recovery. Since CO2-low salinity WAG showed best performance among types by constant pore volume injected. Positive results in both secondary and tertiary modes with Kaolinite free samples used here showed that Kaolinite release is not the critical phenomenon in LSWF brisk performance. Also different pressure behaviour of CO2 WAG processes in comparison with reported behaviour of LSWF proves that LSWF performance may not depend on how pressure changes through flooding.
