Application of Air Drilling Technology in CBM Well of Liulin Area

Abstract:

Air drilling is an important drilling technology to effectively develope coalbed methane with the characteristics of low circulating pressure loss, strong carrying capacity, better hole cleaning and advantages of preventing wellbore leakage and protecting reservoir. But it also faces complicated engineering and geological problems such as wellbore stabilization and hydrodynamic condition. Research was conducted on rock strata features, hydrogeololgy condition, water saturation character and foam drilling mud design; and according to the formation characteristics, the matching technology suitable for air drilling was designed in Liulin district. During the construction of 7 coalbed methane wells in liulin district, drilling period was shortened by 50%, reservoir was protected effectively, and the production of vertical wells and horizontal well reached 1000 cubic meters and 15000 cubic meters with great applicaton prospect.