FIELD: mining.
SUBSTANCE: suggested group of inventions refers to rock destroying tool and to method of well drilling. A percussion drill bit for drilling of underground formation has the central lengthwise axis and operates owing to applying repeated axial percussions to the drill bit at transferring rotation movement around the axis relative to underground fraction. Also the drill bit contains at least one axial cutting element for rock destroying under the effect of axial percussions, it contains chipping cutting elements for cutting drillable rock under the effect of rotation motion; the said chipping cutting elements have the first chipping cutting element. Notably at least one axial cutting element is disposed relative to the first chipping cutting element so as to engage drillable rock during the percussion earlier, than the first chipping cutting element. A drilling system contains a drill column, a percussion drill bit, the first driving facility for drill bit rotation in a well and the second driving facility for executing repeating axial percussions onto the drill bit. The method of well drilling in underground formation consists in following stages: facilitating the said drilling system, arranging the drill bit on underground formation subject to drilling, executing rotation motion of the drill bit around the axis with maintaining force at the drill bit axially directed into underground formation, executing recurring percussions onto the drill bit.
EFFECT: increased service life of drill bit due to increased efficiency of chipping cutting elements.
15 cl, 1 ex, 1 tbl, 8 dwg
