Work

Assessing the impact of reservoir properties on in-situ combustion stability via temperature peaks characteristics

Year: 2025

Type: article

Abstract: In-situ combustion is a promising follow-up technology for shallow, extra-super heavy oil post-steam injection. Evaluating its stability and optimizing parameters through lab tests is crucial. However, existing studies rely on qualitative criteria like "combustion front extinction" rather than quantitative stability indicators. This research proposes a novel method to assess in-situ combustion dynamic stability using temperature peaks and their characteristic parameters. Combustion-tube experiments evaluated permeability and oil saturation effects. Key findings within the studied ranges: The slope ratio of temperature peaks strongly correlates with stability and serves as a quantitative indicator. Stability occurs when slope ratio standard deviation is <2 and range <4; instability occurs when >5 and >10, respectively. Four peak patterns are defined by slope ratios (SR): plateau peak (SR > 10), dragging peak (2 < SR < 10), sharp peak (1 < SR < 2), and front-extended peak (SR < 1). Stability is controlled by gas flow resistance, oil bank evolution, and overriding effects. Reduced permeability and increased oil saturation (>45%) intensify gas resistance and impair oxygen transfer. This, combined with oil bank suppression and late-stage gas channeling from overriding, causes instability (e.g., instability at 0.2 D permeability, worsened at 45% oil saturation). The temperature peak analysis provides dynamic adjustment benchmarks for physical modeling, enhancing experimental success and mechanistic studies. It also offers new technical support for field stability monitoring and optimization in extra-super heavy oil in-situ combustion.

Source: Thermal Science

DOI: 10.2298/tsci250823216h

Authors: Rui Huang, Renbao Zhao, Zhan Hongyang, Ren Haitao, Liu Jiyang

Institutions: China University of Petroleum, Beijing, PetroChina Xinjiang Oilfield Company (China)

Language: English

Topic: Enhanced Oil Recovery Techniques

Subfield: Ocean Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $161