PCR-type Bow-Spring welded Centralizers are applied for casing strings centering during
their RIH and cementing inside wells. Centering of a casing string is provided with preset
bow spring properties of centralizer planks. PCR-type bow-spring centralizers consist
of two shells and 6 bow springs with a specific profile and section.
The principal difference of PCR centralizers from PC centralizers is a plank radially
curved inward and the outer diameter. PCR centralizer outer diameter is less for some
millimeters than well bore diameter which it is run in.
The technical result is achieved through the construction of PCR bow-spring centralizer.
It consists of centering arch planks and two solid shells, the centralizer arch spring
planks have a radial shape in section. This prevents cutting of casing inner surface
with centralizer sharp planks edges and wall layer destruction in open well bore. As
the result, casing passing through a well bore becomes easier, especially in low-angle
and horizontal parts as centralizer arch planks interact with casing and well bore inner
surface through sliding friction with the lowest friction coefficient.