ZDY6000LD (B) directional drilling technology and equipment were used to conduct cross-layer directional drilling for gas drainage in Xiqu Coal Mine of Shanxi Xishan Coal and Electricity Co., Ltd. On March 12, 2021, when 3-2# branch reached 468m, a drilling stuck accident occurred. The technicians of CCTEG Xi’an Research Institute were sent to deal with the accident. They formulated an accident handling plan and decided to adopt large-diameter sleeve-milling fishing technology. This technical plan has been successfully applied in many mining areas. After 8 consecutive days of milling and fishing, all buried drilling tools were successfully salvaged, including YHD2-1000 (A) measurement while drilling system, Φ73mm MECCA drill pipe, Φ73mm downhole motor and Φ94mm drill bit. This saved more than 220,000 USD for the mine.
Ф127mm Sleeve-milling drill pipe
Sleeve-milling drill bit