HYDRAULIC JAR OF DRILLING ASSEMBLY (VERSIONS) AND CONTROL METHOD OF HYDRAULIC JAR Russian patent published in 2010 - IPC E21B31/113 

FIELD: oil and gas industry.

SUBSTANCE: as per one version of the design the hydraulic jar includes tubular housing, spindle located in the housing, annular space between spindle and housing and pressure release mechanism located in annular space. Pressure release mechanism mainly divides the annular space into the first and the second parts. Pressure release mechanism includes the first and the second annular elements connected to each other when pressure in the second part of annular space is lower than the specified value, and the flow channel of fluid medium between the first and second parts of annular space. Flow channel of fluid medium has the first size when pressure in the second part of annular space is lower than the specified value, and the second size exceeding the first size when pressure in the second part of annular space is equal to the specified pressure value or higher.

EFFECT: increasing reliability of the design.

24 cl, 12 dwg