Innovation Series: Advanced Science (ISSN 2938-9933, CNKI Indexed)

Study on the Plugging Effect of Novel Expandable Graphite as Plugging Agent for Steam Flooding

Xianpei Yin, Jinxiang Liu*, Yifei Gao

Key Laboratory of Enhanced Oil and Gas Recovery of Ministry of Education, Northeast Petroleum University, Daqing, Heilongjiang 163318, China

Corresponding Author: Jinxiang Liu

Abstract: Steam flooding technology is widely applied in heavy oil development, yet steam channeling in high-permeability channels greatly reduces thermal efficiency and oil recovery. In this paper, a novel 500-mesh expandable graphite customized by Nanjing Gerifa Carbon Materials Co., Ltd. is adopted as a high-temperature plugging agent for steam flooding treatment. Three groups of sand-pack models with different initial permeability gradients were set up to systematically evaluate its plugging capacity and oil displacement performance. Experimental results demonstrate that the material expands rapidly above 180 °C under steam thermal conditions to block preferential flow paths, with outstanding thermal stability and anti-salinity ability compared with conventional polymer plugging agents. The average plugging rate of three groups of sand packs reaches 83.5%, and the incremental oil recovery ranges from 13.2% to 15.8%. Sand-pack displacement experiments confirm that expandable graphite can effectively adjust reservoir injection profile, restrain steam breakthrough and enlarge the swept volume of steam. This material is easy to prepare and friendly to formation environment, which provides a new option for profile control and channeling prevention during steam flooding exploitation.

Keywords: Expandable graphite; Steam flooding; Plugging rate; Profile control; Sand-pack model; Enhanced heavy oil recovery

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