神木双山区块安全快速钻进钻井液技术

Study on Drilling Fluid Tecnology for Improving Penetration Rate in Shenmu-Shuangshan Block

神木双山区块水平井首次采用三开井身结构,二开裸眼井段将长达2 400 m,在这一井段地层极易出现缩、卡、漏、垮塌等复杂,针对上述技术难题,优选出了安全快速钻进钻井液体系,并在神木双山区块应用了2口井。实验表明,该体系表现出良好的润滑防卡性和良好的井眼净化能力,性能易调控、低滤失、高黏度切力,泥饼薄而韧。在整个斜井段施工过程中,2口井井眼始终处于良好净化状态,起下钻无阻卡,井底无沉砂,很好地解决了长裸眼段下存在的井壁坍塌、润滑防卡、携带岩屑等技术难题,把二开钻井周期缩短到20 d以内,而且确保了12h把φ177.8 mm技术套管安全顺利下至井深2 890 m,创造了长庆水平井下技术套管时间最短的新记录。

The horizontal well in Shenmu-Shuanshan has three sections,with the second section opened for 2,400 m.Problems such as tight hole,stuck,loss and collapes were often encountered in this section.A safe and fast drilling fluid system had been prepared and applied in two wells.Filed application shows that this fluid had desirable property of lubricity and hole cleaning, high quality of the mud cake and low filtration rate.No blockage and no pipe-sticking during tripping,no sand setting in downhole were occurred in the drilling of deviated section.Difficult problems including borehole slough,lubricity,anti-sticking,carry-out and suspending cuttings were solved in large-dimension borehole and long open interval.The drilling period was shortened to within 20 days,at the same time the 7'casings were sent to the depth of 2,890 m safely in 12 hours.