In order to deal with the difficulty of 6～10 rock drillability,2 500 ～ 5 000 Mpa formation hardness,4. 1 ℃/100m average geothermal gradient and low ROP in deep formation of Qingshen gas field, the optimized and revised calculation model for formation water production,gas volume,and borehole stability were used to investigate the gas/foam drilling feasibility in Well Gulong 1. An optimized gas/foam drilling is applied in this well from Quan 2 section to Deng 3 section with depth from 3 100 to 4 301. 4 m and wellbore diameter of 311. 1 mm. The average ROP is 7. 53 m/h,which is 3. 6 times faster than the offset well. The drilling cycles was reduced by 28 days.%针对庆深气田深层岩石可钻性级值高达6～10级、地层硬度高达2 500～5 000 MPa、平均地温梯度高达4.1℃／100m和机械钻速低等难题,应用优选、修正后的地层出水量计算模型、出气量计算模型、井壁稳定性评估模型,对古龙1井的泉二段至登三段地层气体／雾化钻井的可行性进行了研究,优化设计出了气体／雾化钻井技术方案.该钻井技术方案在超深井古龙1井进行了现场应用,应用井段为井深3 100.00～4 301.05 m,应用井段井眼尺寸为311.1 mm.应用结果表明,该井段平均机械钻速为7.53 m/h,是邻井古深1井相同层位常规钻井段的3.6倍,钻井周期同比缩短28 d.
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