泡酸解卡技术在TZ4SH井的实践与认识

Practice and Understanding of Stuck Pipe Releasing Technology by Acid Soaking in Well TZ4SH

水平井卡钻采用泡酸解卡,在塔里木油田塔中区块被证明是最迅速有效的方式。该方法解决了一批水平井卡钻事故,解卡成功率达100%。TZ4SH井解卡作业创造了塔中泡酸解卡多个第一,第一次在非奥陶系地层进行泡酸解卡作业,第一次泡酸地层碳酸盐含量低于90%,第一次使用土酸作业但解卡失败,第一次泡酸作业中发生井壁失稳。实践表明,泡酸解卡不是将卡点的阻碍物完全溶解而是溶解部分阻碍物后使其松动,减弱其对钻具活动的影响。泡酸解卡不仅对卡点岩性及其含量有要求,还要求考虑卡点岩石的胶结强度、井壁稳定性等因素。

It is well known that stuck pipe releasing with acid soaking is the most rapid and effective way in Middle Tarim block of Tarim oilfield, a number of pipe sticking accidents have been solved with success rate of 100%. The sticking re- leasing operation in well TZ4SH is the first time to use acid soaking in non Ordovician strata with the carbonate content less than 90%. The practice shows that the acid soaking does not mean to completely dissolve the obstruction at the sticking poiut, but to partly dissolve obstruction to reduce the interference to drilling tool. For stuck pipe releasing with acid soa- king, not only the lithology and the carbonate content in the sticking point should be learned, but also the cementing strength, borehole wall stability and some other factors should be considered.