Development of a novel self-entry exploitation device for marine natural gas hydrate and the feasibility studies. (15th June 2022)

• Record Type: Journal Article
• Authors: Wu, Xuezhen; Ye, Hongyu; Jiang, Yujing; Li, Dayong; Wang, Gang
• Is Part Of: Ocean engineering. Volume 254(2022)
• Publication Date: 2022-06-15
• Subjects: Marine natural gas hydrate -- Self-entry exploitation device -- Depressurization method -- Torpedo anchor -- Penetration laws -- Gas production characteristics; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.111365
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Natural gas hydrate (NGH) is a potentially green energy resource for the future. Five trial production experiments of marine NGH have been carried out worldwide. However, the currently widely used drilling method has poor economic applicability, and there are still many critical technical problems that need to be solved. Based on the characteristics of marine NGH reservoir and the exploration principle, a novel self-entry exploration device (SEED) according to the penetration mechanism of torpedo anchor was proposed, and the working principle was described in detail. The SEED could significantly reduce the cost of NGH exploitation because it eliminates the need for deepwater drilling rigs. Moreover, unlike traditional cement wellbore, the SEED is an artificial rigid structure that withstands greater depressurization to increase efficiency. The penetration laws and gas production characteristics of the SEED were studied through numerical simulation. The research results show that the penetration depth into the seabed can reach more than 300 m, which can cover most of the NGH reservoirs' depth. The gas production efficiency is significantly improved compared to the traditional wellbore. The SEED has specific potential for exploring marine NGH, providing a new idea for commercial exploitation. Highlights: A self-entry exploration device (SEED) was proposed to enhance gas recovery from natural gas hydrate reservoirs. The new device penetrates into the reservoir by impact and then performs depressurization exploitation. The penetration depth of the device can cover the buried depth of most natural gas hydrate reservoirs. The device consists of a steel structure, allowing for greater pressure drop and expanding contact area with hydrates. New method eliminates the need to drill wells and is reusable, promising a significant reduction in production costs.