Abstract: The models of pressure wave propagation in two phase flow of gas liquid are analyzed.Investigations have proven that the speed of pressure wave propagation in two phase flow of gas liquid is much slower than the liquid or the gas.If the depth of well,the mud properties and any void fraction in bottom are given,the two phase flow of gas liquid patterns and the velocity of gas migration can be determined.Based on real time t and time difference Δt of pressure wave propagation from the bit to surface in annulus and the solution of one dimension quasi linear hyperbolic partial differential equations,the height of gas migration and the void fraction can be detected early after gas influxes into the wellbore.This method is faster in detection time than the method of conventional kick detection.

Key words: blowout, gas influx, pressure wave, two phase flow of gas-liquid

摘要： 压力波在气-液两相流中传播速度模型被分析和研究表明:压力波在气液两相流中传播速度远低于在纯液与纯气中传播速度.在一定的井深及泥浆性能等情况下,对于一定的地层进气量,在环空中将出现对应的气液两相流型及对应的气体上升速度.根据压力波在环空中传播时间变化情况,通过求解气液两相流偏微分方程组,可以在地层气体侵入井眼不久即可检测出气侵高度及气体含量.本方法比传统方法发现气侵的时间早得多.

关键词: 井喷, 气侵检测, 压力波, 气液两相流