酸化解卡方法解除伊朗TBK-8井卡钻事故

伊朗19 2项目TBK-8井在二开空气钻进过程中,由于水层和强水敏性页岩地层在同一井段相遇,使页岩钻屑在雾化环境下粘结成团,无法带出,瞬间沉积在钻头上,形成一个环状堆积。当试图通过活动解卡时,堆积物越挤越死,形成一个圆柱,卡死钻具。现场先后采用了浸泡柴油和解卡剂的解卡措施,都没有取得效果。当发现卡钻位置在灰岩地层时,仅注入15%的盐酸5.5m3,就顺利解卡。因此,对于粘附卡钻以外的卡钻事故,当卡钻位置在碳酸盐岩井段,且酸液能注到卡点以下时,可采用酸化方法解卡。

Acidification backing off technology in Iron TBK-8 well

Air drilling was employed in the second section of the Iron TBK-8 well. The shale cuttings were agglomerating in atomized environment and deposited on the bit instantly forming a annular accumulation as a result of pay zone and strong water sensitive shale coexisting. The conglomerates had a compacting trend and formed a cylinder leading to freeze in the drilling tool when trying to back off by the drilling tool movement. Soak diesel and releasing stuck agents were employed in site but no any effect. Hydrochloric acid with the concentration of 15% was employed and back off operation achieved success in limestone formation. Acidizing backing off is available except for sticking in carbonate formation if acidizing fluid can be below the free point.