METHOD FOR CONTROLLING THE LOWER COLUMN FOR DESCENT WITH SECURITY SYSTEM DUPLICATION Russian patent published in 2022 - IPC E21B33/35 E21B34/16 

FIELD: petroleum and gas industry.

SUBSTANCE: technical result is achieved due to a method for controlling the lower column for descent with safety system duplication, including: closing the lower ball valve of the testing subsea Christmas tree assembly and the shutoff valving of the bypass valve, ensuring cutting of the rope/cable /flexible tubing; activating the emergency disconnection mechanism, ensuring the planned disconnection of the lower column for descent; closing the shutoff valving of the testing subsea Christmas tree assembly, ensuring emergency plugging of the borehole; closing the shutoff valving of the subsea Christmas tree assembly, shutoff valving of the bypass valve, followed by activating the emergency disconnection mechanism, ensuring emergency disconnection of the lower column for descent; activating the backup control of the lower column for descent using an internal hydraulic service line, in case of loss of control signals arriving at the lower column for descent, ensuring activation of the emergency disconnection mechanism with disconnection thereof and disconnection of the tool for descent and ascent of the tubing suspension; wherein additional pressure is supplied by means of an internal hydraulic service line in addition to the force from the apparatus for automatic emergency closing of the upper ball valve and the lower ball valve.

EFFECT: ensured increase in the safety in case of emergency disconnection of equipment as a result of emergency situations.

1 cl, 4 dwg