电磁加热—化学复合解除凝析油堵塞温度分布研究

STUDY ON TEMPERATURE DISTRIBUTION PATTERN DURING APPLICATION OF ELECTROMAGNETIC HEATING COMPOUNDED WITH CHEMICAL INJECTION TO REMOVE CONDENSATE BLOCKAGE

用井下电磁感应加热技术解除凝析气藏近井地层的凝析油堵塞,存在有效加热半径小,高温区域集中于井筒附近的问题,因此提出了电磁加热—化学复合的方法,并进行了研究。建立了井下电磁加热—化学复合解除凝析油堵塞的温度分布数学模型,采用数值方法进行求解。研究结果表明该技术能有效增加加热半径,扩大高温区域;近井地层温度分布受化学剂注入时间、注入速度、电磁加热器功率及化学剂的温度影响,其中注入速度和化学剂的温度是重要的影响因素。建议①应综合考虑经济效益和加热效果等因素,选择合理的注入时间。②考虑到电磁加热器的实际功率,以小流量注入为好。③根据化学剂的温度,设定合理的电磁加热器功率。④需要进一步研究电磁加热—化学复合解除凝析油堵塞技术的热力—化学机理,建立能描述该复杂过程的数学模型。

The downhole electromagnetic heating technology used to remove the condensate blockage in near-wellbore region of a condensate gas reservoir has the disadvantages of small effective heating radius and high temperature zone concentrated near the wellbore. A new electromagnetic heating method compounded with chemical injection is introduced in this article. The related pilot study has been completed, from which a mathematical model for temperature distribution during the condensate blockage removal process is established, which has been solved by numerical method. The study indicates that this technology can increase the heating radius effectively to increase the high temperature area, and the temperature distribution along the near-wellbore region is affected by chemical injection time, injection rate, the power of the electromagnetic heater and the temperature of the chemicals, among which the injection rate and the temperature of the chemicals are the most important factors. So it is recommended that ①to take both the economic benefits and the heating efficiency into consideration to decide a reasonable injection time; ②to adopt a preferred low injection rate considering the actual power of the electromagnetic heater; ③to set up a proper power for the electromagnetic heater according to the temperature of the chemicals; ④ to further study the thermodynamic-chemical working mechanism of this new compounding technology so as to set up a mathematic model demonstrating this complicated process.