Development trend of nearly horizontal directional drilling technology in coal mines of China

The nearly horizontal directional drilling technology in coal mine is a new technology in drilling engineering field,which is mainly used in gas drainage hole and geologic exploration hole.This paper briefly retrospected the status of nearly horizontal directional drilling technology in coal mine underground,characters and coverage for the two main directional drilling measures were analyzed.Based on Chinese coal mine underground geologic conditions,coal properties and directional drilling requirements several suggestions were raised for the application of directional drilling technology.Finally,the expectation for the development trends was made.