CASING STRING CENTRALIZER FOR ITS ROTATION DURING CEMENTING Russian patent published in 2020 - IPC E21B17/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and can be used in cementing casing strings during well construction. Casing string centralizer for its rotation during cementing includes casing installed on casing pipe, made of spring steel and including upper and lower belts in form of cylindrical rings, connected to centering ribs, uniformly located in circumferential direction and arched in plane of convex outwards, and equipped with housing movement limiters. Limiters of movement are fixedly installed on casing pipe and are made in the form of rings with threaded holes, in which fixing screws are installed, which interact with casing pipe. Top and bottom belts of centralizer in the form of cylindrical rings are equipped with seats arranged uniformly along circumference of rings with inner cone, into which steel balls are installed with possibility of interaction with casing pipe. At the same time cylindrical rings are provided on outer side with safety rings excluding steel balls falling out of seats. On outer surfaces of centering ribs there are longitudinal notches.

EFFECT: improving operating reliability of the casing string centralizer and enlarging its operational capabilities due to possibility of free rotation of the casing during cementing.

1 cl, 2 dwg