Open Access

ARTICLE

Experimental Investigation into the Impact of a Viscosity Reducer on the Crude Oil Recovery Rate in a Low-Permeability Reservoir

Baoyu Chen^1,2, Meina Li³, Jicheng Zhang¹, Wenguo Ma^1,*, Yueqi Wang¹, Tianchen Pan¹, Xuan Liu¹

1 Key Laboratory for Enhanced Oil and Gas Recovery of the Ministry of Education, Northeast Petroleum University, Daqing, 163318, China
2 Daqing Oil Field Co. Ltd., Daqing, 163453, China
3 The Second Working Area of the First Oil Production Plant, Daqing Oil Field Co. Ltd., Daqing, 163001, China

* Corresponding Author: Wenguo Ma. Email:

Fluid Dynamics & Materials Processing 2025, 21(6), 1459-1471. https://doi.org/10.32604/fdmp.2025.060255

Received 28 October 2024; Accepted 25 February 2025; Issue published 30 June 2025

Abstract

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 (f) of 92.42%, formulated with a viscosity reducer agent concentration (C_VR) 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 × 10⁻¹ mN/m recorded at a C_VR of 0.2%. As the C_VR increased, the relative permeability curve of the oil phase gradually decreased while the oil-water two-phase region (R_o-wtp) expanded significantly. At a C_VR of 0.1%, the R_o-wtp peaked, making an increase of 7.93 percentage points compared to water flooding. In addition, the final displacement efficiency (E_{R, final}) 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.

---

Keywords

---