Hydraulic push-return impact oscillator

Abstract

The invention discloses a hydraulic push-return impact oscillator, comprising an upper connector, a barrel and a lower connector connected in a threaded manner sequentially from top to bottom. A diversion assembly, a reciprocating drive assembly and a backpressure valve assembly are nested in the barrel. The diversion assembly comprises a guide sleeve, an upper valve block, a valve block, a lower valve block and a distribution plate. The reciprocating drive assembly comprises a drive piston and a reversing valve. The backpressure valve assembly comprises a backpressure valve head, a backpressure valve block and a discharge sleeve. Pumped high-pressure liquid is in the oscillator and diverted by the diversion assembly to provide hydraulic drive horsepower for the reciprocating drive assembly, the reversing valve controls the drive piston to finish an upper stroke and a lower stroke, the drive piston also drives the backpressure valve head to reciprocate, the backpressure valve head periodically opens or closes the backpressure valve block so as to enable a pulse backpressure-relief process in a string, the drive piston will impact on the upper valve block or the lower valve block at the end of each stroke, and therefore, periodical mechanical impact is generated.

Description

technical field [0001] The invention belongs to the technical field of drilling tools for oil and natural gas exploitation, and in particular relates to a hydraulic push-back impact oscillator. Background technique [0002] During the drilling process, the hydraulic oscillator can generate vibration along the axis of the drilling tool assembly or the drill pipe through hydraulic action. During the drilling process, part or all of the drilling tool assembly or the drill pipe is in contact with the well wall, so that friction will be generated during the movement. Vibration along the axis can significantly reduce this friction. Therefore, in all drilling processes, two effects can be produced by reducing friction: it can transfer part of the weight of the drill tool assembly to the drill bit, and reduce the torsional vibration of the drill tool assembly due to friction. [0003] Especially in the directional drilling mode using steerable motors, the frictional resistance gre...

AI Technical Summary

Problems solved by technology

[0005] But at present, hydraulic oscillator tools generally use the screw motor to drive the disc valve to achieve pulse back pressure. The screw motor stator is a special spiral structure of rubber material, and the rotor is a specific spiral structure processed by a special CNC lathe and a special tool. , the cost of the tool is high, and the structure is more complicated

On the one hand, the manufacturing cost is high, and on the other hand, the maintenance of the tools after use is relatively difficult. Professional operators from the original factory are required to disassemble and maintain them in special workshops and special tools. The more common method is to send them back to the original factory for maintenance, resulting in Tool maintenance costs are also high and the maintenance cycle is long, which is not suitable for low-cost operations.

[0006] In addition, when the working fluid is a multiphase fluid such as foam, the screw motor must be equipped with a downhole gas separator to maximize the motor’s effectiveness. Application of Long Horizontal Section Horizontal Wells and Low Pressure Gas Reservoirs

[0007] When the downhole temperature is high or contains chemical substances that are corrosive to rubber, it will often cause the rubber stator of the screw motor to fail, resulting in a short service life

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