Synthesis of SIAPES and Construction and Performance of In-situ Emulsification Oil Displacement System in Low-temperature Oil Reservoirs
W/O emulsion flooding is an effective technology to improve oil recovery in mature oilfields,while the comment emulsion system cannot meet the requirements of W/O emulsion formation and in-terfacial tension reduction at low temperature.In this paper,sodium isomeric dodecanol polyoxyethyl-ene ether sulfonate(SIAPES)was firstly synthesized and characterized.Then,a low-temperature oil reservoir in-situ emulsification flooding system was constructed by compounding with coconut oil alkyl diethanolamide(CDEA).And then,its emulsifying performance,interfacial tension reduction ability,and wettability improvement ability were evaluated.Meanwhile,the enhanced oil recovery potential of system was revealed using an online NMR displacement system.The experimental results showed that the phase transition point of crude oil-formation water emulsification was 60%,while after the interven-tion of oil-water self emulsification with the in-situ emulsification displacement system,the phase tran-sition point increased to 65%,and the viscosity of emulsion after phase change was obviously higher than that of the self emulsification emulsion,and the mobility control ability was enhanced.In addi-tion,the in-situ emulsification system could reduce the interfacial tension of oil and water from 12.00 mN/m to 0.12 mN/m,and improve the wettability of oil-wet core sample.Moreover,under the condi-tion of permeability ratio was 12 and water flooding reaches the economic limit,0.6 PV in-situ emulsi-fication flooding and subsequent water flooding could increase the recovery rate by 26.8%.
in-situ emulsificationlow temperature reservoirenhanced oil recoveryinterfacial ten-sionwettabilitysynthesis
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维普
