A New Mechanical Specific Energy Model for Composite Impact Drilling

Composite impact drilling technology is one of the important techniques to increase drilling speeds in deep hard formations. In order to evaluate the efficiency of drilling with a composite impactor in real time and effectively, and to further improve the drilling speed in deep formations, the mechanical specific energy (MSE) model of drilling with a composite impactor was studied. Based on previous theoretical studies on MSE, and considering the effect of the composite impactor on the axial and torsional impact of the drill bit during operation, a new MSE model for composite percussion drilling was established. The results show that the evaluation of the drilling efficiency by MSE obtained by this calculation model is consistent with the actual situation of a Lufeng X well. It can be more widely used in wells drilled with composite impact tools and meet the needs of field operations.