The effectiveness of computed tomography for the experimental assessment of surfactant-polymer flooding

Abstract

The Surfactant-Polymer (SP) process is a type of Chemical Enhanced Oil Recovery (CEOR) method. They are still a challenge for the petroleum oil industry mainly because of the difficulty in designing and forecasting the process behavior on the field scale. Therefore, understanding of the phenomena associated with a CEOR process is of vital importance. For these reasons, this work discusses the benefits of Computed Tomography (CT) uses for the experimental assessment of a SP process. The research includes a literature review that allows identifying the main CT usages for petroleum engineering and a discussion concerning the effectiveness of mathematic expressions proposed for the tomography images treatment of two-phase flow displacement. The conducted experimental methodology can be reproduced to assess the benefits of any chemical Enhanced Oil Recovery (EOR) process with CT. Thus, this paper assesses the conventional waterflooding (WF) and SP flooding as secondary and tertiary oil recovery methods. The developed study allowed us to evaluate through CT images the porosity and the saturation profiles along the rock sample. Also, CT processed data enabled checking the volumetric material balance and determine the oil Recovery Factor (RF). The doubled checked SP data showed an RF increase of 17 and 10 percentage points for secondary and tertiary chemical injection schemes respect to conventional waterflooding. Finally, comparative results of the water cut (Wcut) evidenced the mobility ratio improvement and reduction on the remaining oil saturation.