Drilling Well Flushing Technology

Abstract：This paper introduces the three core functions of well flushing in drilling: cooling drilling tools, removing cuttings and cleaning the bottom, and supporting the wellbore. It expounds the characteristics and selection requirements of four types of well flushing media. The two mainstream well flushing processes, direct circulation and reverse circulation, are compared, their respective characteristics are analyzed, and the technical parameter control standards for the reverse circulation process are clarified, which can provide a reference for field drilling construction.

Raise Boring Drilling

Abstract: This paper introduces raise boring drilling, a highly efficient vertical shaft construction technique featuring reverse upward excavation from bottom to top. With advantages including high safety, low disturbance, and high efficiency, it is widely applied in mining, underground engineering, and other fields. The technology is divided into two categories: full-face raise boring and core barrel raise boring. Full-face raise boring, including pull-up and jack-up types, is suitable for large-diameter shafts and shafts of varying depths. Core barrel raise boring enables simultaneous shaft formation and geological coring, and is applicable to small‑to‑medium shallow‑to‑medium‑depth shafts. The technology is evolving toward intelligence, greater depth, and unmanned operation.

Bored Pile Drilling

Abstract: This paper elaborates on bored pile drilling technology, identifying bored piles as an important type of cast-in-place end-bearing pile. Compared with precast piles, bored piles feature controllable costs, low steel consumption, strong capability for large-diameter and ultra-deep hole forming, wide geological applicability, and low environmental impact, while still facing deficiencies such as sediment cleaning and borehole wall mud cake issues. It also introduces the basic requirements, characteristics, conventional and innovative drilling processes, and points out the broad application prospects of this technology amid technological innovation.