Abstract: The helical flow of power-law drilling muds in the drill string was studied both theoretically and experimentally. The analytical expressions of the apparent viscosity distribution, the velocity distribution and the flow ratefor the helical laminar flow were derived. The equation giving the pressure drop, the expressions of the stability parameter K, characterizing the transition from laminar to turbulent flow, and its maximum value K_max were established. Experimental studies with aqueous solutions of CMC and PAM showed that the helical laminar flow of the power law fluid in the pipes is transformed into turbulent flow when K_max=400.

摘要： 本文从理论和实验方面研究了石油钻井泥浆常用的幂律液体在钻柱中的螺旋流动规律。推导出了幂律液体圆管螺旋流的视粘度分布、速度分布、流量的解析表达式;进而建立了压降方程和判别流动状态的稳定性参数K及其最大值K_max的解析表达式。通过CMC及聚丙烯酰胺水溶液的圆管螺旋流的实验,证明了理论研究的正确性,并确定了稳定性参数的临界值K_max,c可以取作400。