Work

Experimental Study on the Feasibility of “Radial Jet Drilling + CO2 Huff-n-Puff” for the Development of Shale Oil

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide To enhance shale oil recovery and facilitate sustainable resource exploitation, an innovative integration of CO 2 huff-n-puff and radial jet drilling (RJD) technologies is presented. Its feasibility is verified through core-scale experiments, and the influence of laws of parameters such as the number of huff-n-puff cycles, soaking time, injection pressure, and radial borehole length has been analyzed. The results demonstrate that the “RJD + CO 2 huff-n-puff” significantly improves injectivity in low-permeability shale reservoirs. Under experimental conditions, compared to the core without radial boreholes, the presence of radial boreholes significantly enhances the cumulative oil recovery (CRR) of shale oil, with a maximum improvement of nearly 100%. The CRR of cores shows a logarithmic increase with an increase in the number of huff-n-puff cycles. The first four cycles account for about 85% of the final recovery rate. Increasing the soaking time leads to a gradual rise in the CRR for all core samples. However, prolonged soaking time exhibits limited improvement in the CRR, which means that an optimal soaking time exists. CRR increases consistently with higher injection pressures. In particular, when the injection pressure of CO 2 approaches the miscible pressure, the oil recovery efficiency can be significantly enhanced. The CRR approximately increases linearly with an increase in the radial borehole length. The recommended parameters for the core size CO 2 huff-n-puff experiment are as follows: huff-n-puff cycles 4, soaking time 6 h, and injection pressure 20 MPa. These findings provide a strong theoretical and experimental foundation for applying the “RJD + CO 2 huff-n-puff” technique in low-permeability shale reservoir development.

Source: ACS Omega

DOI: 10.1021/acsomega.5c05003

Authors: Jingbin Li, Rui Li, Zhelin Wang, Jing Wang, Lyu Xinrui, Dongling Xia

Institutions: China University of Petroleum, Beijing, Sinopec (China)

Language: English

Topic: Enhanced Oil Recovery Techniques

Subfield: Ocean Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: China University of Petroleum, Beijing, State Energy Center for Shale Oil Research and Development