Key Takeaways & Executive Findings
- •• Developed an in-situ temperature- and pressure-preserved sampler for marine gas hydrates, addressing limitations of conventional samplers. • The magnetically controlled pressure-preserved controller achieves autonomous triggering and self-sealing with an initial sealing force of 83 N and can maintain pressures up to 40 MPa. • The temperature-preserved system maintains temperature rise within 0.3 °C over 2 hours, ensuring thermal stability. • Field application at Haima Cold Seep successfully recovered hydrate samples under in-situ conditions of 13.8 MPa and 6.5 °C.
Abstract
Marine gas hydrates are highly sensitive to temperature and pressure fluctuations, and deviations from in-situ conditions may cause irreversible changes in phase state, microstructure, and mechanical properties. However, conventional samplers often fail to maintain sealing and thermal stability, resulting in low sampling success rates. To address these challenges, an in-situ temperature- and pressure-preserved sampler for marine applications has been developed. The experimental results indicate that the self-developed magnetically controlled pressure-preserved controller reliably achieves autonomous triggering and self-sealing, provides an initial sealing force of 83 N, and is capable of maintaining pressures up to 40 MPa. Additionally, a custom-designed intelligent temperature control chip and high-precision sensors were integrated into the sampler. Through the design of an optimized heat transfer structure, a temperature-preserved system was developed, achieving no more than a 0.3 °C rise in temperature within 2 h. The performance evaluation and sampling operations of the sampler were conducted at the Haima Cold Seep in the South China Sea, resulting in the successful recovery of hydrate maintained under in-situ pressure of 13.8 MPa and a temperature of 6.5 °C. This advancement enables the acquisition of high-fidelity hydrate samples, providing critical support for the safe exploitation and scientific analysis of marine gas hydrate resources.
1. Introduction
With the sustained growth of the social economy, global demand for oil and gas resources has continued to increase. As the largest importer of oil and gas worldwide, China maintains a high level of external dependence, with oil and gas import dependency rates reaching 77.6% and 42.3%, respectively in 2023 [1,2]. The current energy supply situation remains critical, highlighting the urgent need to advance exploration into the Earth's deep subsurface [3,4]. The search for alternative energy sources to conventional oil and gas has thus become a pressing strategic priority.
Marine natural gas hydrates, due to their vast reserves (with a total estimated reserve of approximately 80 billion tonnes of oil equivalent) [5–7], widespread distribution, and high environmental cleanliness, are widely regarded as a promising strategic substitute energy resource. However, compared with conventional oil and gas, the commercial exploitation of marine natural gas hydrates still faces numerous technical and scientific challenges [8,9]. One of the major obstacles is the lack of comprehensive understanding regarding their in-situ occurrence characteristics in deep-sea environments. At present, most fundamental research r
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Chenghang Fu, Le Zhao, Ling Chen, Guikang Liu, Han Wu, Mingzhu Qi, Ming Zhang, Heping Xie (2025). In-situ temperature- and pressure-preserved sampler for marine natural gas hydrates: Principles, techniques, and field application. SinoTechIntel Verified Research. https://doi.org/10.1016/j.ijmst.2025.09.002
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
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Frequently Asked Questions
What is the main challenge in sampling marine gas hydrates?
Marine gas hydrates are highly sensitive to temperature and pressure changes; deviations from in-situ conditions can cause irreversible alterations in their phase state, microstructure, and mechanical properties, making it difficult to obtain representative samples.
How does the developed sampler maintain pressure?
The sampler uses a magnetically controlled pressure-preserved controller that autonomously triggers and self-seals, providing an initial sealing force of 83 N and capable of maintaining pressures up to 40 MPa.
What temperature stability does the sampler achieve?
The temperature-preserved system, with an optimized heat transfer structure and intelligent temperature control chip, ensures a temperature rise of no more than 0.3 °C within 2 hours.
Where was the sampler field-tested?
The sampler was field-tested at the Haima Cold Seep in the South China Sea, where it successfully recovered hydrate samples under in-situ pressure of 13.8 MPa and temperature of 6.5 °C.
What are the implications of this technology?
This technology enables the acquisition of high-fidelity hydrate samples, which is critical for safe exploitation and scientific analysis of marine gas hydrate resources.
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