Sealing method and experimental study of large-diameter reverse circulation hole hammer

• Published in: E3S web of conferences Vol. 573; p. 1018
• Main Author: Liu, Qi
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 01.01.2024
• Subjects: Circulation; Compressed air; Design; Drilling; Drilling equipment; Field tests; Hammers; Pipes; Roller bits; Sealing; Slag; China
• ISSN: 2267-1242; 2555-0403; 2267-1242
• DOI: 10.1051/e3sconf/202457301018

A reliable sealing structure is the key to achieving reverse circulation drilling technology for large- diameter reverse circulation down the hole hammers, and it is also a difficult point in the design of large- diameter reverse circulation down the hole hammers. The existing large-diameter reverse circulation down the hole hammers are designed based on the sealing structure of the bottom drilling tool body. This article proposes a joint sealing method for hole bottom and hole opening. Based on this sealing method, a bundle type reverse circulation down the hole hammer and hole opening sealing device with a diameter of 710/311mm were developed for hole expansion, and field tests were conducted with a double wall drilling tool with a diameter of 127/70mm. The method achieved good continuous reverse circulation slag removal effect, with an average mechanical drilling speed of 2.1m/h, which is 2.6 times higher than the conventional roller bit hole expansion method. The experimental results indicate that the joint sealing method between the bottom and the mouth of the hole is feasible and worthy of further promotion and application.