苏20-17-15H井是一口三开开发水平井,水平段长869 m,完钻井深为4 620 m,垂深为3 445.27 m。该井刘家沟组地层承压能力低,易发生压力诱导性漏失;安定组、直罗组和石盒子组地层的大段泥岩、砂岩互层水敏性较强,井壁坍塌掉块严重;延安组、延长组地层易缩径,起下钻阻卡严重;纸坊组地层造浆性强,易发生井径扩大;水平井段存在井眼清洁、拖压问题等。该井一开使用膨润土浆钻井液,二开使用聚合物和聚磺钻井液,平均机械钻速为10.27 m/h,三开使用低固相钻井液,平均机械钻速为4.99 m/h,并通过使用相应的维护处理措施,实现了安全、快速的钻进要求。 The Su-20-17-15H well is a three-level open horizontal well with a horizontal section length of 869 m, a finished drilling depth of 4 620 m and a vertical depth of 3 445.27 m. The low pressure bearing capacity of the Liujiagou formation in this well is prone to pressure-induced loss; the large mudstone and sandstone interbeds of the Anding Formation, Zhiluo Formation and Shihezi Formation are highly water-sensitive, and the wellbore collapses seriously Yan’an Formation and Yanchang Formation are easy to reduce in diameter and blockage from bottom hole. The formation of Zaofang formation is strong and the well diameter is easy to expand. There are wellbore cleaning and towing problems in horizontal well. The well opened with bentonite drilling fluid, the second open using polymer and polysulfonic drilling fluid, the average penetration rate of 10.27 m / h, three open low solids drilling fluid, the average penetration rate of 4.99 m / h, And by using the appropriate maintenance measures to achieve safe and fast drilling requirements.