Key Takeaways & Executive Findings
- •• An innovative active temperature-preserved coring method using phase change materials (PCM) is introduced for deep-sea natural gas hydrate (NGH) coring. • The developed active temperature-preserved corer (ATPC) reduces core temperature by more than 5.25 °C compared to passive methods. • A heat transfer model for the ATPC coring process was established and validated with indoor experiments. • ATPC extends the low-temperature state duration of NGH cores to 53.85, 32.87, 20.32, and 11.83 minutes at environment temperatures of 15, 20, 25, and 30 °C, respectively.
Abstract
Natural gas hydrate (NGH) has a bright future as a clean energy source with huge reserves. Coring is one of the most direct methods for NGH exploration and research. Preserving the in-situ properties of the core as much as possible during the coring process is crucial for the assessment of NGH resources. However, most existing NGH coring techniques cannot preserve the in-situ temperature of NGH, leading to distortion of the physical properties of the obtained core, which makes it difficult to effectively guide NGH exploration and development. To overcome this limitation, this study introduces an innovative active temperature-preserved coring method for NGH utilizing phase change materials (PCM). An active temperature-preserved corer (ATPC) is designed and developed, and an indoor experimental system is established to investigate the heat transfer during the coring process. Based on the experimental results under different environment temperatures, a heat transfer model for the entire ATPC coring process has been established. The indoor experimental results are consistent with the theoretical predictions of the heat transfer model, confirming its validity. This model has reconstructed the temperature changes of the NGH core during the coring process, demonstrating that compared to the traditional coring method with only passive temperature-preserved measures, ATPC can effectively reduce the core temperature by more than 5.25 °C. With ATPC, at environment temperatures of 15, 20, 25, and 30 °C, the duration of low-temperature state for the NGH core is 53.85, 32.87, 20.32, and 11.83 min, respectively. These findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.
1. Introduction
Energy is an important topic closely related to human survival and development. Compared with the level of 40 years ago, the total energy consumption in the world has more than doubled [1]. Facing the direct contradiction between increasing energy consumption and global carbon emissions and climate problems, Natural gas hydrate (NGH) has come to occupy a pivotal position within the global energy matrix: (1) It is widely used [2]. (2) Its combustion products are clean [3]. (3) It has made great economic contribution in the world [4,5]. (4) The reserves are abundant [6,7]. (5) It plays an important role in energy transformation [8]. Data from the World Energy Statistical Yearbook (2005–2020) reveal a sustained upward trajectory in global natural gas consumption, with a marked acceleration in growth rates during the observation period [9].
As an unconventional natural gas, NGH has complex reservoir-forming mechanism and harsh occurrence conditions. NGH is produced from water and natural gas at specific low temperatures and high pressures (typically temperatures below 10 °C and pressures above 3.8 MPa) [10]. Therefore, as shown in Fig. 1, it is extensive in deep-sea sediments and continental permafrost zones, and it is easy to undergo phase change decomposition under the action of temperature rise and pressure drop.
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WU Han, HU Yunqi, FU Chenghang, CHEN Ling, HE Zhiqiang, XU Meng, XIE Heping (2025). A PCM-based active temperature-preserved coring method for deep sea natural gas hydrate. SinoTechIntel Verified Research. https://doi.org/10.1016/j.ijmst.2025.08.012
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 limitation of existing NGH coring techniques?
Most existing NGH coring techniques cannot preserve the in-situ temperature of NGH, leading to distortion of the physical properties of the obtained core, which makes it difficult to effectively guide NGH exploration and development.
How does the active temperature-preserved corer (ATPC) work?
The ATPC utilizes phase change materials (PCM) to actively maintain the core temperature during the coring process. It is designed and developed to reduce the core temperature by more than 5.25 °C compared to traditional passive methods.
What is the performance of ATPC at different environment temperatures?
With ATPC, at environment temperatures of 15, 20, 25, and 30 °C, the duration of low-temperature state for the NGH core is 53.85, 32.87, 20.32, and 11.83 minutes, respectively.
How was the heat transfer model validated?
An indoor experimental system was established to investigate the heat transfer during the coring process. The experimental results under different environment temperatures were consistent with the theoretical predictions of the heat transfer model, confirming its validity.
What are the potential applications of this research?
The findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.
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