空气泡沫钻井流体体系及性能评价

Air-foam Drilling Fluid System and Its Evaluation

从保护井壁、提高井壁稳定性等技术要求出发,筛选了高效发泡剂、稳泡剂、泥页岩抑制剂,并确定各组分最佳含量,研制了空气泡沫钻井流体体系,该体系由0.3%TWS+0.15%XC+0.03%YIM+0.5%GXG组成。考察了空气泡沫流体抑制页岩水化膨胀、水化分散能力、岩芯浸泡效果及抗温性能。结果表明,该空气泡沫流体体系页岩24 h水化膨胀量2.64 mm,页岩滚动回收率91.4%,岩芯在配方体系中浸泡24 h完好无损,温度90℃时泡沫体系的半衰期仍保持30 min以上,表明该泡沫配方体系具有较强的抑制性和良好的抗温性,能够较好地解决空气泡沫钻井中井壁失稳问题。

High efficient foaming agent, foaming stabilizer, shale inhibitor and so on were selected to meet the technic requirements for protecting hole, and improving hole stability. The optimum compositions for drilling fluid system were determined,which comprised 0.3% TWS,0.15% XC,0.03% YIM, and 0.5% GXG. The air - foam drilling fluid system was evaluated in inhibiting shale from hydrated expansion, hydrated dispersion, core immersion effect, and temperature - resistance. The result showed the air - foam drilling fluid system had 2.64 mm of expansion after hydrating shale 24 hours, shale rolling recovery of 91.4%. The shale core remain perfect after immersing in drilling fluid system. Half time of drilling fluid system at 90 ℃ remain over 30 minutes showing the system had good inhibitory capability and temperature resistance, thus could solve the problem of the hole instability.