Microvisual Investigation on Steam-Assisted Heavy Oil Extraction Behavior in Heterogeneous Porous Media

Abstract

The heterogeneity of pores, an inevitable and intractable challenge during steam flooding, directly induces channeling phenomenon and seriously suppresses oil recovery. Additionally, prolonged exposure of steam exacerbates the diversion capacity of pores with different sizes, thereby exerting further influence on the shape and amount of remaining oil. Considering the microscopic aspect, the variation coefficient of pore size is remarked to characterize the heterogeneity of porous media. In this work, cores with microcomputerized tomography (micro-CT) and microfluidic models with image recognition are employed to research the oil−water distribution and occurrence of remaining oil affected by temperature and velocity in porous media. The results from core displacement experiments show that high temperature and strong heterogeneity conjointly increase the proportion of membranous oil and decrease the proportion of aggregated remaining oil, indicating that the sweep efficiency is increasing. Specially, when the temperature increases from 100 to 150 °C, the sweep efficiency exhibits a notable increase of more than 15%. In contrast, when the temperature rises from 200 to 250 °C, the corresponding increment is less than 2%. From the results of the microfluidic model, the great injection velocity and weak heterogeneity synergistically expand the horizontal sweep region. Through the examination of the macroscopic distribution and microscopic occurrence of remaining oil during steam flooding with varying injection parameters, the impact of steam flooding on heavy oil in heterogeneous reservoirs can be effectively and comprehensively demonstrated. The findings of this work offer promising application prospects in terms of optimizing the sweep efficiency through the adjustment of steam injection temperature and velocity, which can have positive impacts.

Insights into Molecular Dynamics and Oil Extraction Behavior of the Polymeric Surfactant in a Multilayered Heterogeneous Reservoir

“…However, it is also a tricky problem to observe the microscopic processes to extract the remaining oil in porous media. However, observing the microscopic processes on pulling effect of polymer in porous media is also a tricky problem. , …”

“…However, observing the microscopic processes on pulling effect of polymer in porous media is also a tricky problem. 25 , 26 …”