Design and mechanical optimization of multidirectional pressure-preserved coring system for deep-earth resource exploration

• Published in: International journal of mining science and technology Vol. 35; no. 5; pp. 719 - 735
• Main Authors: Liu, Guikang, Xie, Yachen, Li, Cong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2025
• Subjects: Deep mining; Dynamic interference model; Environmentally and economically sustainable deep-earth resource exploration; Field validation; Magnetic control technology; Multidirectional pressure-preserved coring system; Multidirectional pressure-preserved coring system; Deep mining; Field validation; Dynamic interference model; Environmentally and economically sustainable deep-earth resource exploration; Magnetic control technology
• ISSN: 2095-2686
• DOI: 10.1016/j.ijmst.2025.04.001

Pressure-preserved coring technologies are critical for deep-earth resource exploration but are constrained by the inability to achieve multidirectional coring, restricting exploration range while escalating costs and environmental impacts. We developed a multidirectional pressure-preserved coring system based on magnetic control for deep-earth environments up to 5000 m. The system integrates a magnetically controlled method and key pressure-preserved components to ensure precise self-triggering and self-sealing. It is supported by geometric control equations for optimizing structural stability. Their structure was verified and optimized through theoretical and numerical calculations to meet design objectives. To clarify the self-triggering mechanism in complex environments, a dynamic interference model was established, verifying stability during multidirectional coring. The prototype was fabricated, and functional tests confirmed that it met its design objectives. In a 300-meter-deep test inclined well, 10 coring operations were completed with a 100% pressure-preserved success rate, confirming the accuracy of the dynamic interference model analysis. Field trials in a 1970-meter-deep inclined petroleum well, representative of complex environments, demonstrated an in-situ pressure preservation efficiency of 92.18% at 22 MPa. This system innovatively expands the application scope of pressure-preserved coring, providing technical support for efficient and sustainable deep resources exploration and mining.