Volume 53

The Study On Microscopic Mechanism of Asphalt Particle Zhiqiang Wang, Hanqiao Jiang, Jie Li, Miao Zhang, Anqi He Mengqi Ma,

Abstract

Asphalt particles have the characteristics of high temperature resistance, salt resistance, good stability, oil affinity, and blocking water without blocking oil. They can effectively plug large pores in high temperature and high reservoirs with salt medium and low permeability. At present, there are few studies on the micro-displacement experiment of asphalt particle system. In this paper, the micro-fluidic experiment technology is used to carry out the oil displacement experiment of asphalt particles under the condition of high temperature in the reservoir. The migration and accumulation law of asphalt particles is described, and then the mechanism of asphalt particles is analyzed, and the effect of displacement is quantitatively analyzed. The experiment shows that the asphalt particles enter the water flow channel after injection, and gather at the inlet of the model and the narrow pore throat in the form of a bridge, and self-similar aggregation occurs. The originally dispersed asphalt particles tend to gather and change the distribution of remaining oil. The accumulation effect causes the channel to block, the corresponding channel seepage resistance increases, the system flow range is reduced, the seepage velocity is accelerated, and the injection system passes through the cluster and porous remaining oil, which expands the affected area and also makes the cluster and porous remaining oil become film-like or drip-like remaining oil, increasing the overall recovery degree. Quantitative analysis of the microscopic model with pore throat radius of 40um and 75um shows that for the 40um model, when the asphalt particle injection concentration is 1.0%, the initial water flooding cluster residual oil accounts for 85%, the asphalt particle displacement cluster residual oil accounts for 80.5%, and the subsequent water flooding cluster residual oil accounts for 75%, and the overall recovery degree increases by 8.13%. For the 75um pore throat model, when the injection concentration is 2.5%, the proportion of the remaining oil in the initial water flooding cluster is 60%, the proportion of the remaining oil after the displacement of the asphalt particles is 47%, and the proportion of the remaining oil in the subsequent water flooding cluster is 43.5%, and the recovery degree is increased by 7.02%.

Keywords high temperature and high salt medium low permeability reservoir; asphalt particles; clustered remaining oil; micro-fluidic