CENTRALISER Russian patent published in 2010 - IPC E21B17/10 

FIELD: oil and gas production.

SUBSTANCE: centraliser comprises a shaft and expanding packing elements made of an elastic material and mounted on the shaft. The expanding packing elements are designed as at least two spherical segments running into one another with equidimensional radiuses of spheres closable with their distant end faces towards each other on mainly cylindrical segment of the shaft, and are reinforced with a relatively elastic closed-ladder or squirrel-cage binding mounted in a thrust of the spherical segments. Locks of the closed ladder or the squirrel cage can be designed as longitudinal plates directed along the symmetry axis of the shaft. The end faces of the spherical segments closable towards each other can be overlapped or connected through sleeve bush spacers. Elasticity of the binding can be greater than that of the shaft, but smaller than that of the spherical segments.

EFFECT: improved efficiency of centering the tool.

4 cl, 1 dwg