Home / Standards / GB/T 40547-2021 GB/T 40547-2021 Active Design guidelines for coalbed methane well drilling and completion 煤层气钻完井设计指南 Standard Type GBT ICS 73.040 CCS D20 Status 现行 Issue Date 2021-08-20 Implementation 2022-03-01 Responsible Dept 中国煤炭工业协会 Drafting Unit N/A