蜀南地区定向浅层气井快速钻井技术

Directional and Fast Drilling Technology for Shallow Gas Wells in Southern Sichuan Basin

同福场构造属于蜀南地区威远—龙女寺构造群,在三叠系嘉陵江组地层有较好的油气水显示,是目前勘探的重点。针对该区块上部井漏垮塌频繁、须家河组地层研磨性强、浅层气发育等钻井难点,提出了强化"三强"聚合物无固相钻井液性能、进入气层前尽量降低钻井液密度、优选钻头类型与优化钻井参数、定向钻进多采用复合钻进以避免中途起钻以及强化浅层气井控等多项技术措施。现场应用于同福001-X1井,其平均机械钻速为6.17m/h,钻井周期为17.1d,创造了该构造完钻周期的最短纪录,钻井提速效果明显。

Belonging to the Weiyuan-Longnvshi structure group in southern Sichuan Basin, with a good oil/gas/water show in its Triassic Jialingjiang Formation, the Tongfuchang structure be-comes the key exploration target. Aiming at drilling difficulties of lost circulation and collapse often appearing at the upper, strong formation abrasiveness and developed shallow gas in Xujiahe For-mation,some technical measures have been proposed, such as: (1) strengthening the performance of 'three strongs' (strong block-age, strong inhibition and strong enveloping) polymer non-solid drilling fluid; (2) reducing the drilling-fluid density before enter-ing gas layer; (3) optimizing the bit type and drilling parameters; (4) adopting the compound drilling during directional drilling in or-der to avoid halfway tripping out; and (5) strengthening the well control of shallow gas. Field application to Tongfu 001-X1 well shows that the average penetration rate is 6.17 m/h, and the drill-ing cycle of 17.1-day creates the shortest record for this structure. Drilling rate has been increased obviously.