TY  - EJOU
AU  - Chen, Baoyu 
AU  - Li, Meina 
AU  - Zhang, Jicheng 
AU  - Ma, Wenguo 
AU  - Wang, Yueqi 
AU  - Pan, Tianchen 
AU  - Liu, Xuan 

TI  - Experimental Investigation into the Impact of a Viscosity Reducer on the Crude Oil Recovery Rate in a Low-Permeability Reservoir
T2  - Fluid Dynamics \& Materials Processing

PY  - 2025
VL  - 21
IS  - 6
SN  - 1555-2578

AB  - The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir. This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil to enhance fluid flow within a low-permeability reservoir. At 72°C, the oil-water dispersion solution achieved a viscosity reduction rate (<i>f</i>) of 92.42%, formulated with a viscosity reducer agent concentration (<i>C</i><sub>VR</sub>) of 0.1% and an oil-water ratio of 5:5. The interfacial tension between the viscosity reducer solution and the crude oil remained stable at approximately 1.0 mN/m across different concentrations, with the minimum value of 4.07 × 10<sup>−1</sup> mN/m recorded at a <i>C</i><sub>VR</sub> of 0.2%. As the <i>C</i><sub>VR</sub> increased, the relative permeability curve of the oil phase gradually decreased while the oil-water two-phase region (<i>R</i><sub><i>o-wtp</i></sub>) expanded significantly. At a <i>C</i><sub>VR</sub> of 0.1%, the <i>R</i><sub><i>o-wtp</i></sub> peaked, making an increase of 7.93 percentage points compared to water flooding. In addition, the final displacement efficiency (<i>E</i><sub><i>R, final</i></sub>) achieved with a 0.1% viscosity reducer solution reached 48.64%, exceeding water flooding by 15.46 percentage points, highlighting the effectiveness of the viscosity reducer solution in enhancing oil recovery.
KW  - Low-permeability reservoir; low-viscosity crude oil; viscosity reducer; relative permeability; oil displacement efficiency

DO  - 10.32604/fdmp.2025.060255