The effect of injection pressure on the microscopic migration characteristics by CO₂ flooding in heavy oil reservoirs

ABSTRACT

In heavy oil reservoir, the variations of injection pressures induce asphaltene precipitation by CO₂ flooding, which causes a reduction in recovery. This paper investigated the microscopic migration characteristics by CO₂ flooding at different injection pressures. The results showed that the migration was unobstructed, whereas the spread scope was relatively small at 2 MPa. In case of 8 MPa, there was a mixed area of oil-gas and precipitated asphaltene. A large number of asphaltene precipitations appeared, which inhibited the migration of CO₂ at 10 MPa. Additionally, the maximum recovery under 8 MPa was 58.2%, followed by 10 MPa and 2 MPa, respectively.

KEYWORDS:

• Injection pressure
• heavy oil
• CO₂ flooding
• microscopic migration characteristics
• oil recovery

Acknowledgments

The authors are grateful for the financial support given by the National Natural Science Foundation of China (No. 11372033).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [11372033].

Notes on contributors

Weiyao Zhu

Weiyao Zhu,  male, born in 1960, professor, mainly engaged in the development of oil and gas field.

Qipeng Ma

Qipeng Ma, male, born in 1993, PhD candidate, mainly engaged in tertiary oil recovery technology.

Zhiyong Song

Zhiyong Song, male, born in 1979, professor, mainly engaged in tertiary oil recovery technology.

Jisheng Lin

Jisheng Lin, male, born in 1979, senior engineer, mainly engaged in heavy oil thermal recovery and development.

Ming Li

Ming Li, male, born in 1981, senior engineer, mainly engaged in reservoir transformation technology research.

Bingbing Li

Bingbing Li, male, born in 1988, PhD candidate, mainly engaged in tertiary oil recovery technology.