PUMPING WELL CUT-OFF SYSTEM (VERSIONS) Russian patent published in 2014 - IPC E21B34/06 E21B43/16 

FIELD: oil and gas industry.

SUBSTANCE: cut-off system includes equipment of the well with at least one packer with or without return valve downstream connected to the cut-off landing nipple directly or through one or several tubes, and running in and out of an electric submersible pump unit at the pipe string. At that the cut-off valve consist of a lock, a case with input and output passing channels, sealing collars, a controlled element and a locking group. According to the invention the system is equipped with a hollow shank interconnected hydraulically from bellow to the cut-off controllable element and to the cavity of the pipe string over the electric submersible pump unit from the above. For this purpose the pipe string and hollow shank upstream and downstream the electric submersible pump unit are equipped respectively with axial and off-centre upper and lower couplings with taps interconnected by a hydraulic channel passing close to the electric submersible pump unit. At that the upper coupling has either a through axial channel or a through off-centre channel or a through axial landing channel. When the upper coupling is made with the landing axial channel then a divider for two cavities is run in at the additional pipe string of a less diameter with a side return valve. The lower coupling is connected hydraulically to remote measuring equipment. Besides the hollow shank with or without crossover unit is equipped with a disconnector with a running tool or without it. At that the cut-off valve is either run in to the well or set to the landing nipple before running in of the electric submersible pump unit or run in to the well at the running tool under the hollow shank and placed to the landing nipple. At that the disconnector under the hollow shank is connected to the disconnector or its controlled element or the landing nipple. The cut-off valve with a lock is equipped by a pressure adjuster and its sealing collars are set either lower or upper than the output passing channel. The case and controlled element of the cut-off valve form a working chamber connected through the hollow shank and hydraulic channel to the cavity of the pipe string or additional pipe string over the electric submersible pump unit. The controlled element is made as a piston or plunger or bellows capable of the locking group opening and closing at start-up and shutdown of the electric submersible pump unit or at the target generation or release of excess pressure in the additional pipe string or the pipe string. The closing group is made as a support saddle assembly and a gate or as a cylinder and a plunger gate. The piston or bellows or the gate is spring-loaded under the preset force. The cut-off valve is made with or without control mechanism to fix position of the controlled element rotated at the rod or in a case of a coded bushing with through or blind cam slots designed for the limiter in the case or at the rod respectively.

EFFECT: improving operational efficiency of the pumping well due to prevention of the productive stratum bullheading downstream the packer at replacement of the electric submersible pump unit.

3 cl, 21 dwg