GFT型防塌减阻剂的性能评价与现场应用

Performance Evaluation and Field Application of GFT Anti-collapse and Drag Reduction Agent

为解决现有沥青软化点高、分散性差、较低温度条件下润滑性差及稳定孔壁能力不强等问题,研制了以沥青及树脂材料为主要原料,软化点为35℃的GFT型防塌减阻剂。这种防塌减阻剂具有稳定性好,润滑能力强,在不增加钻井液粘度的同时,可有效降低钻井液的滤失量;沥青质粒子的附着能力强,可有效充填与封堵孔壁微裂缝、微孔隙,粘接破碎岩块或颗粒,提高孔壁稳定性。淡水膨润土基浆中加入1%的GFT型防塌减阻剂,其润滑系数降低率达80%以上。经青海鱼卡煤田勘探区ZK30-7孔及ZK30-8孔2个钻孔的现场应用,证明了GFT型防塌减阻剂对破碎地层具有良好的护壁效果;同时能显著降低钻具扭矩,体现出优良的润滑性能。

In order to solve the high asphalt softening point, poor dispersibility, poor lubricity at relatively low temperature and weak borehole wall stability, GFT anti-collapse and drag reduction agent was developed mainly preparing by asphalt and resin material with the softening point at 35℃.This agent exhibits its advantages of good stability and lubrication; it can effectively reduce the filtration of drilling fluid without the viscosity increasing;due to the strong adhesion ability of as-phaltene particle, the agent can effectively fill and seal the microcracks and microporosity of borehole wall and bond broken rocks or particles to increase the stability.With 1%GFT anti-collapse and drag reduction agent adding into freshwater ben-tonite slurry, the lubricating coefficient decreases is up to more than 80%.Through field application of GFT in boreholes of ZK30-7 and ZK30-8 in Yuqia coalfield exploration region, it is proved that GFT anti-collapse and drag reduction agent has good wall protection effect in broken formation, and can significantly reduce the torque of drilling tool with its excellent lubricity being present.