Drilling technology with guide pipe in the second section pilot hole of large-diameter well in coal mining area

In the process of large-diameter well construction, it's necessary to complete the first section drilling and cement with large-diameter pipe in the surface hole to reduce the risk of subsequent reaming. But this step could lead the pilot hole of the second section to reduce drilling speed as carrying cuttings incompletely. Finally we have put forward setting guide pipe drilling technology to solve the cycling problems by means of theoretical analysis and site comparative test. Practices show that it has important referential value for the second section drilling of large-diameter well by using drilling technology with guide pipe.