Patent ID: 11885223
Assignee: THE CHARLES MACHINE WORKS, INC.
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 18:
19. The method of claim 18 further comprising:
after rotating the inner pipe string with the first motor such that the first rotation rate and the second rotation rate are equal:
ceasing rotation of the inner pipe string and the outer pipe string;
removing a section of the inner pipe string and the outer pipe string; and
thereafter, repeating the steps of:
rotating the outer pipe string using a second motor;
measuring a first rotation rate of the inner pipe string;
measuring a second rotation rate of the outer pipe string;
determining if the first rotation rate exceeds a predetermined threshold; and
if the first rotation rate exceeds a predetermined threshold, rotating the inner pipe string with the first motor such that the first rotation rate and the second rotation rate are equal.