The latest development of HDD pipeline crossing technologies

In this paper, the latest development of horizontal directional drilling (HDD) pipeline crossing technologies at home and abroad was analyzed to realize the crossing of pipeline with larger diameter in the longer distance and improve the crossing capacity and equipment level of HDD. The large HDD crossing engineering at home and abroad in recent years and the newly adopted technologies and equipments were summarized. It is proposed that HDD pipeline crossing technologies are currently developing in the direction of large project, large drilling rig and large drilling tools. A series of new HDD equipments are developed, including the HDD rig with the maximum pullback force up to 1 500 t, heavy wall drill pipe whose wall is twice as thick as that of ordinary drill pipe, drill pipe with body diameter of 244 mm, flexible modularized drilling rig, and PDC bit and PDC reamer cone suitable for hard rock beds. And besides, HDD positive reaming technology is also applied more and more. The latest development plays an important guiding role in promoting the improvement of HDD construction technologies & equipments and the development of HDD business in China.