小井眼钻具升降产生的孔内波动压力

Wellbore dynamic surge pressure while tripping a drill pipe in slim hole drilling

钻具在充满钻井液的钻孔内运动时所产生的波动压力是影响钻孔稳定的主要因素。为了研究影响孔底波动压力的因素,对俄罗斯学者的试验数据进行回归分析,得出波动压力与起下钻速度、钻孔深度成正比关系,并受钻井液性能、钻孔结构等参数影响,得出波动压力计算公式。经过工程实例验证,该公式计算结果准确可靠,能满足工程实际需要。

Dynamic surge pressure is the main factor that influences the stability of drilling hole while tripping a drill pipe in geologic drilling. In order to study the influence factors of the dynamic surge pressure, through the regressive analysis and probability statistics of russian scholar＇s experimental data, the paper demonstrates that the surge pressure has direct ratio relations with velocity of pipe trip and the depth of borehole and is also affected by the factors such as drilling fluid property, hole structure, and so on, and the formula of the surge pressure is finally given. The results of engineering cases prove that the formula is reliable, and the precision of prediction can meet engineering need.