Quantitative macro and micro analysis on enhanced oil recovery (EOR) mechanisms of multi-component composite steam flooding (MCCSF) based on image recognition algorithm

Abstract

Multi-component composite steam flooding (MCCSF) has emerged as a promising method for enhancing oil recovery (EOR) in heavy oil reservoirs. However, its complex EOR mechanisms remain unclear, and a quantitative evaluation method for production performance in the process has not been established. In this paper, one dimensional (1D) displacement experiments were conducted to measure the oil displacement efficiency (ODE), and the optimal composite mode of multi-components was selected. This was coupled with two dimensional (2D) visualization experiments to investigate the macroscopic and microscopic EOR mechanisms during the process of MCCSF. Image recognition algorithms and image segmentation techniques were introduced to quantitatively analyze the volume of remaining oil (VORO) and the sweep efficiency at different locations during the different displacement stages. The results indicated that the integration of foams and viscosity reducer (VR) significantly improved both sweep efficiency and ODE. Finally, the effective oil production period was obviously extended. The ODE in the 1D experiments reached 76.3%, and the overall sweep efficiency in the 2D visualization experiments reached 97.97%. During pure steam flooding (PSF), the swept area was mainly targeted the near-well zone and the main flow channel. However, after adding foams and a VR for along with steam flooding, the remaining oil in the side channels and corner zones was effectively mobilized, and the ODE in the central swept areas and the displacement front were significantly enhanced, resulting in a final oil recovery factor (ORF) of 74.72%, which was 46.71% higher than that of PSF. This study primarily investigated the EOR mechanisms of MCCSF from two perspectives: improving ODE and sweep efficiency. These findings provided valuable insights and offer a quantitative method for the development effect evaluation.