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Modelling of ASP Flooding Using X-ray CT Core Flooding Experiments
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, IOR 2015 - 18th European Symposium on Improved Oil Recovery, Apr 2015, cp-445-00057
- ISBN: 978-94-6282-141-5
Abstract
This paper describes efforts to model tertiary Alkaline Surfactant Polymer (ASP) core flooding experiments. ASP model parameters can be determined from such experiments by history matching pressure drop and effluent data only. However, these matches are non-unique, do not allow discrimination between different model assumptions needed to obtain the match, and consequently result in large uncertainties when extrapolated to field scale. In this paper, dynamic fluid saturation distributions obtained with X-ray computer tomography during ASP flooding experiments are used to improve the conceptual understanding of the ASP process and to validate possible history matched models. Application: The paper presents history matches of a series of tertiary ASP core flooding experiments that used X-ray tomography to visualize the mobilization of oil remaining after water flooding of a 100 cP, active crude. Results of extended fractional flow analysis, and one, two, and three dimensional “effective” ASP numerical models are compared. Results, Observations, and Conclusions: • All models applied can be tuned to reproduce the oil production profiles and the characteristic self-similar cross-sectional averaged oil saturation profile observed in the experiments. • The observed surfactant production profiles are best captured with the two or three dimensional models in which fingering is triggered locally in the area downstream of the oil bank. • Three dimensional simulations show fingering patterns in the area downstream of the oil bank that are qualitatively similar to the patterns observed during the X-ray CT experiments. Significance: Models of the displacement mechanisms of ASP flooding of relatively viscous active crude are validated by means of dynamic fluid saturation distributions obtained with X-ray CT visualization. The resulting improved understanding of the process increases the confidence in potential full field application of ASP flooding.