Development of Technology for Entrainer-Enhanced CO2 Flooding: Status Report.

摘要

The results of studies conducted to evaluate the development of the technology for utilizing entrainers for carbon dioxide (CO(sub 2)) flooding are described. Experiments were conducted to determine the extent of the fluid-property enhancement (gas-phase density and viscosity) of CO(sub 2) + hydrocarbon and CO(sub 2) + crude oil systems in the presence of selected entrainers (cosolvents). The improvement in CO(sub 2)-rich phase hydrocarbon extraction capacity was also determined in the presence of added cosolvents. The hydrocarbon systems used in the study were n-hexadecane and a crude oil sample from Bloomington (TX) field with an API gravity of 22.7(degree). Preliminary entrainer screening studies were conducted utilizing gas and liquid chromatographic approaches to determine relative affinities of certain cosolvents with target high-molecular-weight hydrocarbon solutes. These solutes ranged in molecular weights from n-decane (n-C(sub 10)) up to n-tetracontane (n-C(sub 40)). These qualitative screening methods were useful in identifying potential cosolvents that may be used for future study. A method of utilizing entrainers to enhance the extraction of polymeric materials into the CO(sub 2)-rich phase was also investigated. This approach utilized a simple extraction apparatus to determine relative degrees of polymer extraction in CO(sub 2)as a function of pressure and the degree of enhancement of extraction in the presence of added cosolvent. 10 refs., 15 figs., 2 tabs.