METHOD FOR DRILLING AND REPAIRING WELLS WITH LOW FORMATION PRESSURES AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2024 - IPC E21B7/00 E21B21/08 E21B29/00 E21B37/00 

FIELD: oil and gas industry.

SUBSTANCE: invention can be used when drilling and repairing wells with abnormally low formation pressure (ALFP). A drill string with a working tool is lowered into the well, into which a device is installed between the upper and the lower parts, including a jet pump and a self-sealing cup-type packer element, configured to rotate relative to the axis of the device to ensure tightness during operation of the device and dividing the annulus of the well into the upper and the lower annulus. An active fluid flow is supplied through the upper part of the drill string into a device in which the active fluid flow is divided into two parts. One part of the flow is directed into the lower annulus of the well to circulate fluid in the near-wellbore zone. The other part of the flow is directed to a jet pump, which lifts the passive medium along the bottom of the drill string from the bottom-hole zone and directs it to the upper annulus of the well for removal to the surface. The bottom is cleaned by moving the drill string down, drilled and milled by rotating the drill string with the working tool while simultaneously moving down or up.

EFFECT: loss of drilling fluid is minimized when carrying out work in wells with ALFP.

4 cl, 10 dwg