加压解卡工艺在XS1井的应用

Application of pressurization and getting-unstuck technology in the XS1 well,Sichuan Basin

常规解卡工艺一般用于压差黏附卡钻事故的处理,实践中暴露出解卡操作时间长的缺陷并存在解卡成功率低的风险。为满足提速提效要求,有效解除黏附卡钻事故,探索了采用关井加压浸泡解卡剂工艺。,分析了黏附卡钻发生条件和机理,介绍了加压解卡的原理:将解卡剂替至准确卡钻位置后,采用下压钻具、关井,然后用小排量注入钻井液对环空加压,加速解卡剂向钻具与井壁之间的泥饼渗透,对泥饼产生破坏、分解作用,减少钻具和泥饼接触面积,从而能够有效、快速解卡。该工艺在四川盆地XS1井首次使用并获得成功,证明了该方法能降低事故处理时间和提高解卡成功率,有效减少事故损失。

The conventional technology of getting unstuck is usually adopted for dealing with the accidents of differential pressure sticking,but in actual field practices,there exposed the shortcoming of long operation time and the risk in a low success ratio of stuck freeing.In view of this,this study first explored the way of pressurization and the releasing stuck agent being soaked after shut-in of a well.First,based on the mechanism of differential pressure sticking,the principle of pressurization and stuck freeing was introduced.After the releasing stuck agent was positioned to the right location of sticking,the drilling tools were drilled down and the well was shut in,then a small amount of drilling fluid was injected to add pressure in the annular space.In this way,the releasing stuck agent could be accelerated into the mud cake between drilling tools and well wall,destroying and decomposing the mud cake and reducing the contact area between drilling tools and mud cake.As a result,effective and rapid stuck freeing could be achieved.This technology was first successfully applied in the XS1 well in the Sichuan Basin,which proves that this method can not only reduce the time of dealing with the accident of sticking but improve the success ratio of stuck freeing,thereby to cut down the huge loss from downhole accidents.