| 摘要 |
FIELD: mining.SUBSTANCE: during operation in casing string, drill string bottom layout is raised by reducing fluid density in casing string above drill string bottom layout, creating upward force applied to drill string bottom layout. When drill string bottom layout is lifted in casing string, fluid is pumped to top end of annular space, and displaced fluid is discharged from top end of casing string. Fluid flow supplied to top end of annular space is monitored and compared to displaced fluid flow discharged from casing string.EFFECT: enhanced efficiency of drill string bottom layout lifting.20 cl, 14 dwg |
