METHOD FOR DRILLING WELLS ON DEPRESSION Russian patent published in 2005 - IPC

FIELD: mining industry.

SUBSTANCE: closed circulation of drill mud is performed by volumetric type pump, included in assembly of drilling tool immediately before chisel. As a pump of volumetric type reversed screw face drive is used. Portion of rotations of drilling column is spent on rotation of screw pump rotor. Operation of rotor starts when load is applied to stator in form of hydraulic resistances to flow in drilling column, chisel and ring-shaped space and reaction of face during application of axial load to chisel. All power spent on drilling is transferred through drilling column to screw pump and chisel. Pressure of drill mud, fed by common slurry pump, on mouth in manifold, is minimal. Feeding of drill mud into manifold is performed in low-pressure mode. Aeration of drill mud is performed by feeding gas into manifold together with mud. Mouth bracing of drill plant made with possible control of well in case of fluid influxes is utilized. Operation of volumetric type pump is used to provide al hydraulic power, spent on circulation of drill mud, including compensation of hydraulic losses in drilling column, in ring-shaped space, in nozzles of chisel and with transfer of required hydraulic energy to provide hydro-monitoring effect of hydro-monitoring jets coming from chisel nozzles, and also hydraulic losses in mouth bracing of drilling plant.

EFFECT: lower energy costs, cheaper operation.

1 dwg, 1 ex