元坝地区超深含硫气井安全快速钻井难点及对策

川北元坝地区是中国石化南方海相重点勘探区域，其钻井完钻井深超过7 000 m，属于超深含硫气井。针对该区陆相地层研磨性强、可钻性差，井身质量控制难度大、海相地层盐膏层发育、井漏和井控安全问题突出等施工难点，提出了安全快速钻井技术对策：①运用气体钻井技术提高机械钻速，减少井漏复杂事故；②结合邻井资料，优选钻头类型，优化钻井参数；③制订井下安全钻井技术措施，预防地层掉块和键槽卡钻、缩径和压差卡钻、断钻具和钻头等井下复杂情况的发生。

Challenges and counter-measures for safe fast drilling in ultra-deep sour gas wells at Yuanba area

Yuanba area is a key exploration area of Sinopec in the north Sichuan basin. The wells drilled are ultra deep sour gas wells with a total depth of each exceeding 7000 m. The continental strata there have such features as being abrasive, having poor drillability, being hard to control wellbore quality, and the ocean strata there are characterized by the developed gypsum rock beds, lost circulations and difficult well control. Safe and rapid drilling technical measures are suggested as follows: a. gas drilling technology should be adopted to improve the ROP and reduce many accidents like circulation loss; b. bit type and other drilling parameters should be optimized according to the data of neighboring wells; c. safety countermeasures should be planned out to prevent downhole accidents such as formation collapse, sloughing hole sticking, pressure differential shrinking &; sticking, drilling pipe and bit breaking, etc.