Waterflood-assisted oil recovery with sulfate-spiked seawater would cause incompatibility scaling in carbonate reservoirs and reduce economic benefits.This research investigated the benefits of polyphosphate compounds...Waterflood-assisted oil recovery with sulfate-spiked seawater would cause incompatibility scaling in carbonate reservoirs and reduce economic benefits.This research investigated the benefits of polyphosphate compounds in reducing scaling potential as well as its effect on oil recovery when mixed in high sulfate flood water.Severity of scaling potential of sulfate-spiked water in a carbonate reservoir environment was measured,followed by systematic screening of a polyphosphate compound,which successfully inhibited the sulfate scale precipitation at concentration as low as 100 ppm.The new formulation(seawater with four times sulfate and phosphate,SW4 SP)was evaluated and compared with benchmark formulation(modified seawater with four times sulfate,SW4 S).Contact angle,ζ-potential and drainage studies show that SW4 SP changed the rock wettability from oil wet to water wet to a larger degree compared to SW4 S.Improved recovery efficiency of SW4 SP was confirmed through a set of core flooding studies in the tertiary and quaternary flood modes.Whereas SW4 S recovered 7.7%of original oil in place(OOIP),SW4 SP recovered about 8%of OOIP in the tertiary mode under approximately identical flow conditions.Flooding with SW4 SP in the quaternary mode following a tertiary flood with SW4 S on the same core resulted in 1.7%additional oil recovery,showing improved efficiency of the new flood water formulation.展开更多
Prebiotic peptide synthesis is a central issue concerning life's origins. Many studies considered that life might come from Hadean deep-sea environment, that is, under high hydrostatic pressure conditions.However,...Prebiotic peptide synthesis is a central issue concerning life's origins. Many studies considered that life might come from Hadean deep-sea environment, that is, under high hydrostatic pressure conditions.However, the properties of prebiotic peptide formation under high hydrostatic pressure conditions have seldom been mentioned. Here we report that the yields of dipeptides increase with raised pressures.Significantly, effect of pressure on the formation of dipeptide was obvious at relatively low temperature.Considering that the deep sea is of high hydrostatic pressure, the pressure may serve as one of the key factors in prebiotic peptide synthesis in the Hadean deep-sea environment. The high hydrostatic pressure should be considered as one of the significant factors in studying the origin of life.展开更多
文摘Waterflood-assisted oil recovery with sulfate-spiked seawater would cause incompatibility scaling in carbonate reservoirs and reduce economic benefits.This research investigated the benefits of polyphosphate compounds in reducing scaling potential as well as its effect on oil recovery when mixed in high sulfate flood water.Severity of scaling potential of sulfate-spiked water in a carbonate reservoir environment was measured,followed by systematic screening of a polyphosphate compound,which successfully inhibited the sulfate scale precipitation at concentration as low as 100 ppm.The new formulation(seawater with four times sulfate and phosphate,SW4 SP)was evaluated and compared with benchmark formulation(modified seawater with four times sulfate,SW4 S).Contact angle,ζ-potential and drainage studies show that SW4 SP changed the rock wettability from oil wet to water wet to a larger degree compared to SW4 S.Improved recovery efficiency of SW4 SP was confirmed through a set of core flooding studies in the tertiary and quaternary flood modes.Whereas SW4 S recovered 7.7%of original oil in place(OOIP),SW4 SP recovered about 8%of OOIP in the tertiary mode under approximately identical flow conditions.Flooding with SW4 SP in the quaternary mode following a tertiary flood with SW4 S on the same core resulted in 1.7%additional oil recovery,showing improved efficiency of the new flood water formulation.
基金supported by the National Natural Science Foundation of China (Nos. 21778042 and 41576081)the Fundamental Research Funds for the Central Universities(No. 20720160034)
文摘Prebiotic peptide synthesis is a central issue concerning life's origins. Many studies considered that life might come from Hadean deep-sea environment, that is, under high hydrostatic pressure conditions.However, the properties of prebiotic peptide formation under high hydrostatic pressure conditions have seldom been mentioned. Here we report that the yields of dipeptides increase with raised pressures.Significantly, effect of pressure on the formation of dipeptide was obvious at relatively low temperature.Considering that the deep sea is of high hydrostatic pressure, the pressure may serve as one of the key factors in prebiotic peptide synthesis in the Hadean deep-sea environment. The high hydrostatic pressure should be considered as one of the significant factors in studying the origin of life.
