A new simulation method for nanoparticles solution flooding based on connection element method

Abstract

Nanotechnology is widely used in medicine, electronics, materials, and energy fields. An important aspect of nanotechnology is its application in enhancing oil and gas recovery. However, the oil displacement mechanism using nanotechnology is complicated. Generally, numerical simulation methods and experiments are used to provide a simple description of the oil displacement mechanism, leading to the current inability to accurately characterize the actual underlying mechanism. Based on the connection element method, this paper proposes a new characterization method for the numerical simulation of nanoparticle solution flooding in oil reservoirs, In this case, the reservoir is considered the interaction relationship between connecting elements, and the flow rate, and oil saturation on a single connecting element are calculated. The oil displacement mechanism of nanoparticle solution flooding is investigated by focusing on increasing viscosity, changing formation permeability, and fluid relative permeability. The oil displacement mechanism expressed in this model is considered when the nanoparticles are dissolved in the base fluid (water). Herein, a dual-media model of nanoparticle solution flooding is established to describe the fractured reservoirs. The model was validated by comparing with water flooding when the nanofluids concentration is close to zero. The results show that the fitting rate can reach 98%. The proposed model was also used in an actual reservoir, the fitting rates between the calculated oil rate and actual production of four typical production wells reached 81.4%, 84.5%, 86%, and 82%. The water content decreased from 13% to 11%, and cumulative production increased by 17% after the addition of nanoparticles.