天然气勘探与开发2025，Vol.48Issue(4)：90-97,8.DOI:10.12055/gaskk.issn.1673-3177.2025.04.009
深层页岩气⌀311.2mm井眼安全快速钻井优化配套技术
Optimized supporting technologies for safe and rapid drilling of ⌀311.2mm borehole for deep shale gas:A case study of Da'an block in western Chongqing
摘要
Abstract
In order to improve the safe drilling efficiency of ⌀311.2 mm borehole for the deep shale gas in the Da'an block of western Chongqing on the southeastern margin of the Sichuan Basin,some supporting technologies including the bit selection,drilling fluid optimization,acid-gas control,and lost circulation treatment were adopted to address the technical challenges,such as the wellbore collapse and bit balling up in the Lower Jurassic Lianggaoshan-Ziliujing Formations,the strong abrasiveness of the Upper Triassic Xujiahe Formation,the developed pyrite and chert in the Upper Permian Longtan-Middle Permian Qixia Formations,and the lost circulation and acid-gas contamination in the Lower Triassic Jialingjiang-Middle Permian Maokou Formations.The stratigraphic characteristics and drilling difficulties were analyzed,and the key measures for enhancing the rate of penetration(ROP)in hard-to-drill formations were identified.In addition,drilling parameters and bottom hole assembly(BHA)were optimized,and an anti-contamination drilling fluid system and the lost circulation treatment process were improved.The results show that,(i)the application of drill bits SD6542BF and ES1656TEU in the Xujiahe Formation,and GS1606T,SD6542BF and TS616 in the Longtan-Qixia Formations increases the ROP to 6.36 m/h and 3.47 m/h,respectively;(ii)the high-density organic salt polysulfonate drilling fluid system,combined with calcium oxide,calcium chloride and gypsum treatment agent can effectively address acid-gas contamination,maintaining the pH value of drilling fluid equal to or greater than 10 and the calcium ion concentration greater than 600 mg/L;(iii)the implementation of the three-level measures of plugging while drilling,targeted bridge-slurry plugging,and cement plugging improves significantly the success rate of lost circulation treatment,reducing the proportion of lost circulation-related non-productive time(NPT)to 0.48％;and(iv)the optimized trajectory design and screw curvature(1.00°-1.25°)and the increased proportion of composite drilling have achieved one-trip drilling of Xujiahe Formation 7 well times,with an average drilling cycle of 26.28 d and a ROP of 6.58 m/h.It is concluded that the supporting technologies can significantly improve the drilling efficiency of ⌀311.2 mm borehole in the Da'an block,and provide technical support for the safe and efficient development of deep shale gas.关键词
四川盆地东南缘/渝西大安区块/深层页岩气/钻头优选/钻井液优化/酸性气体防控/井漏处置/钻井提速Key words
Southeastern margin of the Sichuan Basin/Da'an block of western Chongqing/Deep shale gas/Bit selection/Drilling fluid optimization/Acid-gas control/Lost circulation treatment/ROP enhancement分类
能源科技引用本文复制引用
简旭,王军,贺立勤,黄彦发,付华才,邓开建,钟广荣,蔡刚..深层页岩气⌀311.2mm井眼安全快速钻井优化配套技术[J].天然气勘探与开发,2025,48(4):90-97,8.基金项目
中国石油集团川庆钻探工程有限公司科研项目"渝西大安—永川区块311.2mm井眼优快提速技术研究"(编号:CQ2024B-5-Z5-3). （编号:CQ2024B-5-Z5-3）
