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凝析气井开采过程中，当地层压力小于露点压力时，将在地层中发生反凝析现象，凝析液在井筒附近产生附加表皮系数，导致产气量下降。对反凝析污染进行评价，可以为不同开发时期产能的合理调整提供依据，有效提高气田的开发效益。文章应用气藏工程和数值模拟方法对丘东凝析气藏不同开采时期及整个开采过程的反凝析污染进行了评价，并优选出消除丘东气田近井带反凝析污染的注气气源、注气量和注气时效。计算结果表明，丘东气田气井投产第二年出现近井带反凝析污染，污染主要发生在距井筒10 m以内；考虑到丘东气田的地面建设以及吐哈油田天然气开发的实际特点，采用间歇注气来解除反凝析污染；丘陵LPG干气作为间歇注气消除近井带凝析污染的首选气源，合理的注入气量为4.5×１０４ｍ３，气田从第三年末开始注气，每半年注一次，连续注9 ａ，可以获得较高的累积采气量。

EVALUATION AND ELIMINATION OF CONDENSATE GAS WELL DAMAGE CAUSED BY RETROGRADE CONDENSATION CONTAMINATION 1)

Retrograde condensation will happen when the formation pressure drops below the dew point pressure during the production process of condensate gas wells. The additional skin coefficient produced by the condensate liquid near the well–bore will lead the gas production decreasing. Evaluation of condensate gas well damage caused by retrograde condensation contamination will offer the information for properly adjusting the productivity of condensate gas wells in different stages and effectively improving the exploitation benefit. Using the gas reservoir engineering and numerical simulation methods, the retrograde condensation contamination is evaluated in the different production stages and the whole exploitation process for Qiudong condensate gas reservoir. The gas injection source, volume and time are optimized to eliminate the retrograde condensation contamination near the well –bore for Qiudong condensate gas reservoir. The results show the retrograde condensation contamination will occur in the second year after the gas reservoir is put into production. And the damage range is no more than 10 cm. from the bore hole wall. According to the characteristics of infrastructure in Qiudong gas field and gas exploitation in Tuha oil field, intermittent gas injection should be adopted to eliminate the retrograde condensation contamination. The dry gas from LPG in Qiuling oil field is first selected as the gas source of intermittent gas injection to eliminate the retrograde condensation contamination near the well–bore. The reasonable gas injection volume is 45000 m 3 each time. The gas injection should start from the third year, twice a year, lasting for 9 years, which may obtain more cumulate gas production.