新型承压堵漏技术在吐哈盆地L356井的应用

Application of A New Pressure-bearing and Sealing Technique in Well L356 of Tuha Basin

在吐哈盆地台北凹陷鄯善弧形构造带侏罗系三间房组下部地层勘探开发钻井过程中,恶性井漏频繁发生,严重影响了丘陵油田的开发上产效果。针对该区块恶性漏失问题,通过对井漏漏失规律的分析,研发了一种新型承压堵漏技术,该技术利用不同粒径的不规则刚性封堵剂的边缘效应,在裂缝中挂住架桥,大颗粒架桥,小颗粒逐级填充;复配各种弹性材料和可变形的材料进一步封堵,在近井壁形成一层致密的隔层,阻止裂缝的继续扩延,展现了新型堵漏材料的封堵能力,从而提高地层承压能力。通过室内试验,利用JHB-Ⅱ高温高压堵漏试验仪,开展动态模拟堵漏试验,结果可承压6MPa。新型承压堵漏技术提高了地层承压能力,在L356井的成功应用,为该区块恶性井漏堵漏技术提供借鉴作用,具有良好的推广应用价值。

In the process of exploration and development drilling,malignant lost circulation was induced frequently in Jurassic Sanjianfang Formation of Shanshan arc tectonic belt in Taibei Sag of Tuha Basin,which seriously affected the development effect of Qiuling Oilfield.In allusion to problem of malignant lost circulation,through the analysis of the lost circulation,a new drilling fluid technology of pressure-bearing and sealing of the lost circulation was developed,for the technology irregular rigid edge effect of blocking agent with different particle sizes was used to hang the bridge in fractures,it was packed gradually by using large particles bypass and a small particles in the cracks.And it was further blocked by combining elastic material with deformable material,a dense interlayer was formed nearby the wellbore to prevent continuous expansion of fracture,therefore the pressure capacity was raised.Through laboratory experiments,JHB-II high temperature and high pressure static leaking tester is used,it showed that the dynamic simulation test can bear 6MPa pressure.Based on the operation requirement of Well L356,the applied pressure is up to 3.5MPa,pressure stabilizing is 60 min with pressure drop of zero,the problem of serious lost circulation is successfully solved in Well L356,its loading capacity is improved and it provides a good wellbore condition for subsequent drillings.