高含水油气混合物井筒结蜡特性研究

Study on Wax Deposition Characteristics of Wellbore with High Water-Cut Oil-Gas Mixture

为有效治理结蜡问题,必须探究油气田开发周期内井筒结蜡规律,针对不同生产参数下结蜡特点制定相适应的防治措施。建立了高含水油气混合物井筒结蜡模型,分析了不同参数对井筒结蜡的影响。结果表明:随着产液量的增加,初始析蜡井筒里程向后偏移,流体内部蜡沉积量显著减少,但管壁最大结蜡厚度基本不变。随着流体温度的升高,流体内蜡沉积体积分数明显降低,初始析蜡井筒里程向后偏移,当地层流体温度低于75℃时,应注意设置清蜡防蜡措施。随着压力的升高,流体内蜡沉积体积和管壁结蜡厚度变化并不明显。当含水率升高时,流体内蜡沉积体积分数和管壁最大结蜡厚度明显降低,在油田开发后期高含水阶段,井筒结蜡量相对较少,可适当减少部分清蜡措施。

In order to effectively control the problem of wax deposition,it is necessary to explore the law of wax deposition in wellbore during the development cycle of oil and gas fields,and formulate appropriate prevention and control measures according to the characteristics of wax deposition under different production parameters.A wellbore wax deposition model of high water-cut oil-gas mixture was established,and the influence of different parameters on wellbore wax deposition was analyzed.The results showed that with the increase of liquid production rate,the initial wax deposition wellbore mileage shifted backward,and the wax deposition inside the fluid decreased significantly,but the maximum wax deposition thickness of the pipe wall remained basically unchanged.As the fluid temperature increased,the wax deposition volume fraction in the fluid decreased significantly,and the initial wax precipitation wellbore mileage shifted backward.When the formation fluid temperature was lower than 75℃,wax removal and anti-wax measures should be taken.As the pressure increased,the volume of wax deposition in the fluid and the thickness of the wax deposition on the pipe wall did not change significantly.When the water cut increased,the volume fraction of wax deposition in the fluid and the maximum wax deposition thickness of the pipe wall decreased significantly.In the high water cut stage of oilfield development in the later stage,the amount of wax deposition in the wellbore was relatively small,and some wax removal measures could be appropriately reduced.