摘要:
为进一步增加顺煤层定向钻孔深度、提高超长定向钻孔钻进效率,分析了顺煤层超长定向钻孔钻压传递影响因素,包括钻孔轨迹、钻孔深度、孔内沉渣和钻遇地层;以保德煤矿2 570 m顺煤层超长定向钻孔为工程背景,对复合定向钻进状态下钻压传递规律进行了研究。研究结果表明:① 随着钻孔深度的增加,滑动定向钻进给进压力呈指数型上升,最终达到钻机额定给进压力,钻压传递效率降低;复合钻进状态下,随着钻孔深度的增加,复合钻进给进压力始终保持在较低水平,且远低于钻机额定给进压力,钻机回转压力近似呈线性增长,但低于钻机额定回转压力,钻压传递效率高。② 泥浆泵泵压和泵量越高,排渣效率越高,钻具摩擦阻力越小,钻压传递效率越高,反之钻压传递效率越低。
Abstract:
In order to further increase directional borehole depth along coal seam and improve drilling efficiency of ultra-long directional borehole, influencing factors of weight on bit(WOB) transmission of ultra-long directional borehole along coal seam were analyzed, including borehole trajectory, borehole depth, sediment in borehole and drilling strata. Based on engineering background of 2 570 m ultra-long directional borehole along coal seam in Baode Coal Mine, law of WOB transmission under compound directional drilling was researched. The research results show that with the increase of borehole depth, feed pressure of sliding directional drilling increases exponentially, and finally reaches rated feed pressure of drilling rig, which leads to decrease of transmission efficiency of WOB. Under condition of compound drilling, feed pressure of compound drilling keeps at a low level with the increase of borehole depth, which is far lower than rated feed pressure of drilling rig. Rotary pressure of drilling rig almost increases linearly with the increase of borehole depth, but it is lower than rated rotary pressure of drilling rig, which leads to high transmission efficiency of WOB. The higher the pump pressure and pump volume of mud pump are, the higher the slag discharge efficiency is, the lower the friction resistance of drilling tool is, and the higher the transmission efficiency of WOB is. Conversely, the lower the transmission efficiency of WOB is.