注烃溶蜡处理技术在凝析气田的研究与应用

Research and application of hydrocarbon injection and wax dissolving treatment technology in condensate gas field

关键词:  注烃溶蜡  天然气  防蜡  蜡堵  低温分离器

Key words:  hydrocarbon injection and wax dissolving  natural gas  wax prevention  wax plugging  low-temperature separator

摘要:

在克深处理厂天然气处理过程中,因J-T阀及低温分离器析蜡导致系统堵塞,致使装置处理量受限,同时外输气烃露点不合格。针对此问题开展防蜡工艺研究,通过实验及HYSYS软件模拟分析蜡堵的具体原因后得出,克深区块的天然气组分不连续,C₅~C₈组分缺失,多环芳烃类物质存在于气相中,无法被溶解分离,在进入低温环境后容易凝结析出,最终导致低温分离器内构件堵塞。通过实验和现场运行经验以及理论计算,根据相似相溶原理制定技术解决路线,采用HYSYS软件模拟分析,从原料气空冷器前注入轻烃,补充缺失组分,解决了蜡堵问题,单套处理装置恢复设计处理量。井口天然气组分分析的准确性对处理装置的设计至关重要,对新开发气田组分化验要求由C₇提高到C₃₀,并形成相应的组分分析方法,研究成果成功地同步推广应用到蜡堵的克深处理厂,取得了良好的效果,对类似含蜡气田的建设具有借鉴意义。 

Abstract:

During the process of natural gas treatment in Keshen Treatment Plant, the wax precipitation from J-T valve and low-temperature separator caused the blockage of system, which limited the capacity of natural gas unit and caused unqualified hydrocarbon dew point of exported gas. The wax prevention process was studied to solve the problem. Through experiments and HYSYS software simulation, the specific causes of wax blockage were analyzed. It was concluded that the natural gas components in Keshen block were discontinuous. Due to the lack of C₅ to C₈ components, polycyclic aromatic hydrocarbons existed in the gas phase and could not be dissolved and separated, so it was easy to condense and precipitate after entering the low temperature environment, which eventually led to the internals blockage of the low temperature separator. Through the experiment, field operation experience and theoretical calculation, the technical solution route was formulated according to the principle of similar compatibility principle. Through HYSYS simulation analysis, light hydrocarbon was injected from the front of the feed gas air cooler to supplement the missing components, so as to solve the problem of wax plugging, and the design capacity of a single treatment unit was restored. The accuracy of component analysis of wellhead natural gas was very important for the design of processing device. The requirement for component analysis of newly developed gas field was increased from C₇ to C₃₀, and corresponding component analysis method was formed. The research results were successfully applied to Keshen Treatment Plant with wax plugging, and good results were obtained, which has a reference for the construction of similar waxy gas field.