Evaluation of Polymers as Direct Thickeners for CO2 Enhanced Oil Recovery

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• 作者：Shiyang Zhang ; Yuehui She ; Yongan Gu
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2011
• 出版时间：April 14, 2011
• 年：2011
• 卷：56
• 期：4
• 页码：1069-1079
• 全文大小：1049K
• 年卷期：v.56,no.4(April 14, 2011)
• ISSN：1520-5134

文摘

In this paper, two commercial polymers, poly(vinyl ethyl ether) (PVEE) and poly(1-decene) (P-1-D), are tested to thicken CO₂ for CO₂ enhanced oil recovery (EOR). First, a series of laboratory tests are conducted to measure the cloud-point pressures of either polymer at different polymer solubilities in supercritical CO₂ and the equilibrium interfacial tensions (IFTs) of a light crude oil-pure or polymer-thickened CO₂ system under different reservoir conditions. Second, a capillary viscometer is used to measure the viscosities of polymer-thickened CO₂ at different test pressures. Third, a total of six high-pressure CO₂ coreflood tests are performed to examine the effects of polymer-thickened CO₂ on the total CO₂ EOR. It is found that at the same and low polymer solubility in pure CO₂, the measured cloud-point pressure of PVEE is much lower than that of P-1-D. The measured equilibrium IFT for polymer-thickened CO₂ at a high pressure is much lower than that for pure CO₂. The PVEE- or P-1-D-thickened CO₂ viscosity is approximately (13 to 14) times higher than the pure CO₂ viscosity. The CO₂ coreflood test results show that PVEE- or P-1-D-thickened CO₂ flooding can further enhance oil recovery after a pure CO₂ breakthrough. The CO₂ breakthrough can be significantly delayed if polymer-thickened CO₂ is injected directly.