内喷孔式反循环钻头结构优化设计及CFD模拟分析

Optimal Design of Internal Jet Orifice Reverse Circulation Bit and CFD Simulation Analysis

摘要:

为解决贯通式潜孔锤反循环连续取心（样）技术在钻进“硬、脆、碎”等复杂地层时反循环排不出渣或者排渣不彻底的现象，在现有贯通式潜孔锤反循环连续取心钻头结构的基础上，优化设计一种新型内喷孔式反循环钻头，能在孔底形成强有力的多股引射抽吸流场，并模拟分析了内喷孔轴线水平偏角和内喷孔轴线与钻头中心的偏距2个结构参数对新型反循环钻头结构抽吸能力的影响。通过模拟分析的验证，此种反循环钻头的结构更加简单,反循环效果比较优良。

Abstract:

With hollow-through DTH hammer reverse circulation continuous coring (sample) technology, slagging or halfway slagging while drilling in the “hard, brittle, broken” complex formations are often encountered; to solve these problems, a new type of internal jet orifice reverse circulation bit was optimally designed on the basis of the existing hollow-through DTH hammer RC bit, which can form the powerful multilevel injection-suction fluid field. The article also imitates and analyzes the influence of 2 structural parameters of internal jet orifice level angle and the offset distance between internal jet orifice axis & the bit midpoint to the suction capacity of new RC bit structure. The simulation analysis has verified that the structure of such a RC bit is simpler with good reverse circulation effect.