FIELD: drilling of oil and gas wells, particularly, devices for centering of casing strings. SUBSTANCE: centralizer includes hollow body and clamping bushing. Located on body and clamping bushing are centering ribs in form of spiral. Lead of helix of body rib is larger that that of helix of clamping bushing rib. Screw threads of opposite direction are made on internal conjugated surfaces of body and clamping bushing. Direction of spiral of body centering ribs is opposite to direction of its internal screw thread. EFFECT: higher reliability of centralizer fastening to casing. 2 cl, 3 dwg
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|---|---|---|---|
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| CONTROLLED ASSEMBLY OF BOTTOMHOLE MOTOR FOR DRILLING OF DIRECTIONAL AND HORIZONTAL WELLS | 1997 |
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RU2131967C1 |
