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.

Water- and Surfactant-Based Huff-n-Puff Injection into Unconventional Liquid Hydrocarbon Reservoirs: Experimental and Modeling Study

“…Computational tomography (CT) scanning was used as a supporting method for the determination of oil saturation at each filtration stage. The standard procedure of saturation calculations based on tomography images is described in ref 44. The current study used two contrasting tomography agents to compare their efficiency: KI was applied for the water phase when brine was tested as an oil displacement fluid in the experiment (1), and IC8 was applied for oil in the experiment (2) with surfactant filtration.…”

Effects of Core Size and Surfactant Choice on Fluid Saturation Development in Surfactant/Polymer Corefloods

“…Microfluidics and micro X-ray computed tomography (CT) have allowed for insights into a range of microscale phenomena such as stability of emulsions and pore-scale distribution of fluids. , However, by nature, these two approaches are restricted in both sample and viewing size and, as such, are often used as prescreening experiments, or in combination, to corefloods; promising exception being larger micromodels capturing macroscale behavior successfully . Medical X-ray CT, on the other hand, allows for imaging of representative core samples and, most commonly, extraction of saturation profiles. , Despite this, only rarely have these studies expanded on the direct imaging results, notable cases being the incorporation of internal profiles in evaluating modeling approaches and the provision of insights into the existence of instabilities in the underlying displacement process …”

“… 43 Medical X-ray CT, on the other hand, allows for imaging of representative core samples and, most commonly, extraction of saturation profiles. 44 , 45 Despite this, only rarely have these studies expanded on the direct imaging results, notable cases being the incorporation of internal profiles in evaluating modeling approaches 46 and the provision of insights into the existence of instabilities in the underlying displacement process. 47 …”