Constant-pressure and constant-quantity type swab and constant-pressure and constant-quantity swabbing method

Abstract

The invention provides a constant-pressure and constant-quantity type swab and a constant-pressure and constant-quantity swabbing method. The constant-pressure and constant-quantity type swab comprises an upper joint, a sealing assembly, a valve body, a valve element assembly and a fishing socket; the upper end of the upper joint is connected with a ball connector, a center pipe is connected intothe lower end of the upper joint, and a first liquid outlet hole is formed in the side wall of the upper joint; the sealing assembly sleeves the periphery of the central pipe; the upper end of the valve body is directly or indirectly connected to the lower end of the central pipe, a pore plate cover is arranged on the inner side of the upper end of the valve body, and a ball seat short section isconnected to the inner side of the lower end of the valve body; the valve element assembly is arranged between the pore plate cover in the valve body and an upper end opening of the ball seat short section, an annular gap is formed between the valve element assembly and the inner side wall of the valve body, and the upper end opening of the ball seat short section is blocked by the valve element assembly under the action of gravity; and the fishing socket is connected to the outer side of the lower end of the ball seat short section, and a barb elastic piece is arranged on the inner side wallof the lower end of the fishing socket. The constant-pressure and constant-quantity swabbing method is implemented by adopting the constant-pressure and constant-quantity type swab.

Description

technical field

[0001] The invention relates to the field of liquid drainage and swabbing equipment for oil testing operations in low-permeability oilfields, in particular to a constant-pressure and constant-volume pump and a constant-pressure and constant-volume swabbing method thereof. Background technique

[0002] At present, hydraulic pumps are used in the oil well testing operation site to carry out oil testing operations, but during the pumping process, due to the quality of the rubber cartridges matching the pumps, improper operation by the operator, deep submersion or rough inner wall of the tubing, etc. It is very easy to cause the suction rubber tube to fall off in small pieces or in pieces and fall into the oil pipe. Continue the pumping operation, and the fallen rubber cartridge fragments float on the liquid surface, making it difficult for the pump to enter the liquid surface to extract the liquid. When the pumping rubber cartridge falls off too much, it is eas...

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