DEVICE FOR COMBINED AND SEPARATE OPERATION AND MAINTENANCE OF FORMATION PRESSURE IN TWO PRODUCTIVE FORMATIONS IN OFF-LINE MODE Russian patent published in 2013 - IPC E21B43/00 

FIELD: oil and gas industry.

SUBSTANCE: device consists of a production string, on the string head of which there installed are injection valves including a head valve with a sealer installed on it, a tee-piece with a side tap for supply of injection fluid to upper formation by means of tubing string. A packer is installed on the tubing to isolate lower formation from upper formation. In order to supply injection fluid to lower formation and perform underground repair, the device is equipped with a string of flexible pipes, which passes through the sealer, which are located inside the tubing string, and with an additional packer that together with the first packet isolates the well space related to upper formation. The tubing string is equipped in its lower part with the sealer of flexible pipe string and equipped with a branch pipe with a fastener that retains it. The lower part of the branch pipe is equipped with a check valve, and upper part is equipped with a controlled check valve and a disconnector, the lower part of which is connected to the branch pipe and the upper one is connected to flexible pipe string. A circulation valve is installed on the tubing string between packers.

EFFECT: maintenance of formation pressure.

1 dwg