Abstract:  Sustained casing pressure ( SCP) problem frequently occurs during the production stage of natural gas wells at Gaoshiti-Moxi block, the effects of the wellbore temperature variation on the cement sheath integrity during the well production are studied using cement-sheath integrity model. Design requirements, technical parameter optimization of the well cementing slurry and related technical measures are thus proposed to improve the cement-sheath integrity at this area. After these technologies applied on site, no SCP has occurred during the completion and oil testing of the well at Gaoshiti-Moxi Block. Besides, the risk of SCP during the production has also been reduced. This technology has a promising prospect in the prevention of SCP in natural gas wells.

Key words:  , cement sheath, sealing integrity, SCP, temperature variation, natural gas well 

摘要：  针对高石梯－磨溪区块天然气井生产期间易出现环空带压的问题，采用水泥环密封完整性模型分析生产期间井筒内温度变化对水泥环密封性能的影响，提出了固井水泥浆设计要求、工艺参数优化等提高该地区水泥环密封完整性的固井配套技术措施。该技术现场应用后，高石梯－磨溪区块完井试油期间未发生环空带压现象，且生产期间的环空带压风险也有所降低；因此该技术在预防天然气井环空带压方面具有很大的推广应用前景。

关键词:  , 水泥环, 密封完整性, 环空带压, 温度变化, 天然气井