CASING STRING SHOE Russian patent published in 1997 - IPC

FIELD: oil and gas production industry. SUBSTANCE: this relates to drilling and fixing of oil and gas wells, and namely to tools and devices for cementation of producing and intermediate technical casing strings. Improved quality of cementation of casing strings is ensured due to fact, that device has hydraulic motor. Motor is made up of stator secured on lower part of casing string, and rotor fixed in stator. Rotor is fixed by means of axial and radial supports. Rotor together with stator form space of working members. Also provided is unbalanced weight which is secured on lower end of hydraulic motor. Unbalanced weight is made with at least one flat in outer surface and with passage located against flat. This passage connects inner space of unbalanced weight with outer space. Rotor is also made with inner space and with holes. These holes connect space of working members with inner space of rotor and further with inner space of unbalanced weight. EFFECT: high efficiency. 2 dwg