Open Access

ARTICLE

Oil Production Optimization by Means of a Combined “Plugging, Profile Control, and Flooding” Treatment: Analysis of Results Obtained Using Computer Tomography and Nuclear Magnetic Resonance

by Yanyue Li¹, Changlong Liu¹, Wenbo Bao^1,*, Baoqing Xue¹, Peng Lv¹, Nan Wang¹, Hui Li¹, Wenguo Ma²

1 Cnooc (China) Co., Ltd., Tianjin Branch, Tianjin, 300452, China
2 School of Petroleum Engineering, Northeast Petroleum University, Daqing, 163318, China

* Corresponding Author: Wenbo Bao. Email:

Fluid Dynamics & Materials Processing 2022, 18(3), 737-749. https://doi.org/10.32604/fdmp.2022.019139

Received 05 September 2021; Accepted 18 December 2021; Issue published 22 February 2022

Abstract

Due to long-term water injection, often oilfields enter the so-called medium and high water cut stage, and it is difficult to achieve good oil recovery and water reduction through standard methods (single profile control and flooding measures). Therefore, in this study, a novel method based on “plugging, profile control, and flooding” being implemented at the same time is proposed. To assess the performances of this approach, physical simulations, computer tomography, and nuclear magnetic resonance are used. The results show that the combination of a gel plugging agent, a polymer microsphere flooding agent, and a high-efficiency oil displacement agent leads to better results in terms of oil recovery with respect to the situation in which these approaches are used separately (the oil recovery is increased by 15.37%). Computer tomography scan results show that with the combined approach, a larger sweep volume and higher oil washing efficiency are obtained. The remaining oil in the cluster form can be recovered in the middle and low permeability layer, increasing the proportion of the columnar and blind end states of the oil. The nuclear magnetic resonance test results show that the combined “plugging, profile control, and flooding” treatment can also be used to control more effectively the dominant channels of the high permeability layer and further expand the recovery degree of the remaining oil in the pores of different sizes in the middle and low permeability layers. However, for the low permeability layer (permeability difference of 20), the benefits in terms of oil recovery are limited.

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