凝析气井水合物生成变化规律研究

Study on the Variation Law of Hydrate Generation in Condensate Gas Well

基于井筒温度压力分布模型和水合物生成模型,综合考虑等温闪蒸模型和定容衰竭因素,提出了针对凝析气井水合物生成条件的计算方法,并且用C++编程语言对模型进行编写。以雅克拉凝析气田X井为例,分析了凝析气井在同一时刻和不同时刻的水合物生成变化规律。研究结果表明:在计算凝析气井水合物生成条件时,必须考虑相态变化;不同衰竭压力下,井筒中水合物生成的温度曲线不同;同一地层压力下,随深度增加,水合物生成温度升高;井筒任意位置,随地层压力的降低,水合物生成温度降低。

The paper presents a calculation method of hydrate formation conditions and the numerical model is programmed with C language by considering constant temperature flash model and constant volume depletion based on the models of the distribution of temperature and pressure along wellbore and the formation of hydrate.The paper takes Well X of Yakela condensate gas reservoir for an example and the variation law of hydrate formation of a condensate gas well under the conditions of the time and different times respectively is analyzed.The study shows that phase state alternation must be considered when hydrate formation conditions are calculated for a condensate gas well;the temperature curves are different under different depletion pressures along wellbore;the temperature at which hydrate forms increases with the increase in depth under a given formation pressure;the temperature at which hydrate forms decreases with the decrease in formation pressure under a given formation pressure at any position along wellbore.