Computerized Tomography Study of the Microscopic Flow Mechanism of Polymer Flooding

Abstract

The microscopic flow mechanism of polymer flooding was examined using an industrial microfocus computerized tomography system. On the basis of scanned slices acquired in the process of water flooding and polymer flooding, three-dimensional visualization of oil and water distribution in different flooding conditions was achieved with a series of image processing methods, including pre-processing, interpolation, segmentation, and three-dimensional construction, which are effective techniques for both the qualitative description and the quantitative characterization of the microscopic flow mechanism. This study has confirmed the suggestion that the displacement efficiency of polymer flooding is higher than that of water flooding, and effectively revealed the microscopic mechanism of oil recovery in polymer flooding. The water/oil mobility ratio was improved after polymer flooding, which resulted in a break of the "equilibrium" flow field that was formed during water flooding and the redistribution of the regions of oil saturation. The remaining oil was flushed out as the result of the flow redirection and the viscoelastic effect of polymer flooding. Compared to water flooding, polymer flooding increased the microscopic sweep efficiency as well as the microscopic displacement efficiency, and thereby the ultimate oil recovery.

Effect of porous media properties on the onset of polymer extensional viscosity

“…Generally after primary and secondary stages of oil recovery, only 30-40% of initial oil in place will be recovered and large amount of oil will remain in reservoir. Thereby, as the third stage of field development, several techniques are proposed which Seright et al, 2009) recently some experimental results (Urbissinova et al, 2010) along with numerical studies (Afsharpoor and Balhoff, 2013;Bai et al, 2011;Xia et al, 2008) and CT image visualization (Hou et al, 2009;Meybodi et al, 2011) demonstrated that in some cases, the polymer can also mobilize the trapped oil (Bakhitov et al, 1980;Cheng et al, 2010;Sherbone et al, 1967;Wang et al, 2001b;Wu et al, 2007). Several reasons are proposed to explain this observation such as polymer adsorption Kohler, 1987, 1988), viscoelastic effect (Huifen et al, 2004;Wang et al, 2000Wang et al, , 2001aWang et al, , 2001bWu et al, 2007), shear thickening (Delshad et al, 2008;Jones, 1980) and memory effect (Hossain et al, 2009).…”

Prediction of Microscopic Remaining Oil Distribution Using Fuzzy Comprehensive Evaluation

“…The total scanned length is 1.25 mm, and 100 slices are scanned with a constant distance along the length direction. After image preprocessing, interpolation, and segmentation, the 3-D structure is reconstructed with the combination of the marching cube algorithm (Lorensen and Cline 1987;Hou et al 2009). Thus, the 3-D visualization is realized.…”

Compatibility of Polymer and Remediation Agents for Enhanced Soil Remediation

“…The essence of improving displacement efficiency in polymer flooding lies in the fact that polymer flooding can increase the oil/water mobility ratio, break the "equilibrium" system to divert waterways, and redistribute oil saturation [1]. However, literature shows few applications of polymer floods in environmental field, especial for soil remediation.…”