离心式湿气压缩机转子在线清洗技术——以莺歌海盆地乐东气田为例

On-line cleaning of the rotor of a wet gas centrifugal compressor:A case from the Ledong Gas Field in the Yinggehai Basin

莺歌海盆地位于莺歌海盆地的中海油乐东气田3台湿气离心压缩机由于叶轮结垢破坏了转子动态平衡,导致压缩机振动值超过设点引起压缩机停机,如果将压缩机送回厂家进行解体清理叶轮结垢物则维修周期需要3个月,这将影响该气田的稳定生产。为此,通过分析压缩机叶轮结垢的成因和压缩机结构原理,在充分做好压缩机密封系统保护的前提下,提出了离心压缩机转子在线清洗的技术思路:采用淡水浸泡清洗法除掉转子的叶轮表面上NaCl、KCl等易溶于水的垢盐;采用冰醋酸清洗液浸泡法除掉不溶于水的CaCO3和MgCO3,循环清洗过程中,检测到pH值不再升高,说明压缩机叶轮污垢已清洗干净。现场实践结果表明,所提出的在线清洗方法可以有效地去除压缩机叶轮结垢,降低压缩机转子振动值,保障了压缩机的安全平稳运行,为治理此类问题开拓了一条新的思路和方法。

In this case of three wet gas centrifugal compressors in the Ledong Gas Field, Yinggehai Basin, the impeller fouling was destroying the rotor dynamic balance until the compressors failed to work when their vibration exceeded the set point. If the compres sors were sent back to the factory with the impeller being removed and cleaned, at least 3 months would be needed so that the steady production of this field would be badly influenced. In view of this, we analyzed the origins of the impeller fouling as well as the struc tures and principles of three compressors. After the compressor seal system was completely well protected, we presented an idea of on-line cleaning of the compressor rotor. First, the soak cleaning by plain water was adopted to deal with the soluble scale forming deposits on the impeller surface, like NaCl, KCl, etc. Then, the insoluble CaCO3 and MgCO3 were cleaned by soaking in the glacial acetic acid. During the whole on-line cleaning process, if the measured pH value was not rising, we would know that the impeller fouling was cleaned. The field practices demonstrated that the proposed on-line cleaning method can effectively remove the scaling de- posits in the compressor impellers and decrease the rotor vibration so as to guarantee the safe and steady operation of a compressor. This study provides an idea and solution to solving the similar problems.