CASING PIPES CONNECTION ASSEMBLY Russian patent published in 2018 - IPC E21B17/02 E21B17/08 

FIELD: mining.

SUBSTANCE: group of inventions refers to equipment used in conjunction with operations performed in underground wells. Well system comprises a casing string installed within the wellbore and having an upper casing section and a lower casing section, a casing connector, an upper coupling sleeve, a lower coupling sleeve, and an inner coating applied to the respective inner cylindrical surfaces of the upper and lower couplings. Casing connector is mounted within the wellbore and is located between the upper and lower casing sections, the casing connector having an upper end and a lower end. Upper coupling sleeve has a first portion attached to the upper section of the casing, and a second portion connected to the upper end of the casing connector, the first and second parts of the upper coupling being secured to each other by an upper contact surface. Lower coupling has a first portion attached to the lower section of the casing, and a second part connected to the lower end of the casing connector, the first and second parts of the lower connecting sleeve are secured together by a lower contact surface. Inner coating extends axially at least along the upper and lower contact surfaces. While each first part of the upper and lower couplings is made of a first material, and each second part of the upper and lower couplings is made of a second material different from the first material.

EFFECT: high resistance to wear of the casing connector.

25 cl, 4 dwg