Well drilling acceleration tool

A speed-enhancing drilling tool, comprising:

• an upstream drill string, including a drive motor and a first driving rod coupled with the drive motor, wherein the first driving rod extends in an axial direction, and the drive motor is configured to drive the first driving rod in rotation;
• a downstream drilling bit;
• and
• a percussive device installed between the upstream drilling string and the downstream drilling bit, and configured to generate impact on the downstream drilling bit in the axial direction, the percussive device comprising:
• a rotary driving part configured to rotate around its axis, and having an upper end engaged with the first driving rod to rotate together with the first driving rod;
• a rotary working part having an upper end engaged with a lower end of the rotary driving part and a lower end connected with the downstream drilling bit, wherein the rotary working part is configured to be driven by the rotary driving part to rotate about its axis, and axially movable relative to the rotary driving part;
• and
• a percussion generating part arranged around the rotary working part and having an upper end abutting against an elastic member, wherein the percussion generating part is configured to move along the axial direction relative to the rotary working part, so as to impact the rotary working part downwardly along the axial direction under action of the elastic member,
• wherein the rotary driving part further comprises a second driving rod connected to a lower end of the first driving rod, and the second driving rod comprises an upstream segment and a downstream segment connected to the upstream segment, an outer diameter of the upstream segment being smaller than that of the downstream segment, wherein a lower driving tooth with an upwardly facing surface is formed on an outer wall of the second driving rod at an area connecting the upstream segment with the downstream segment,
• wherein the percussion generating part further comprises a percussive sleeve arranged around the second driving rod, the percussive sleeve including a first sleeve segment and a second sleeve segment located below and connected with the first sleeve segment, an inner diameter of the first sleeve segment being smaller than that of the second sleeve segment, wherein an upper driven tooth with a downwardly facing surface is formed on an inner wall of the percussive sleeve at an area connecting the first sleeve segment with the second sleeve segment, and
• the percussive sleeve is able to reciprocally move axially relative to the second driving rod under cooperation of the lower driving tooth and the upper driven tooth when the second driving rod rotates relative to the percussive sleeve.