DOWNHOLE APPARATUS AND METHOD FOR WELL ACTIVITIES (OPTIONS) Russian patent published in 2018 - IPC E21B33/13 E21B43/26 

FIELD: mining.

SUBSTANCE: group of inventions relates to methods for well activities, well cementing, well system. In the method, the well system comprises a downhole apparatus defining an axial flow passage with a cement volume and including a section with a changing profile along the axial flow passage. And the device comprises a housing and a plurality of sealing elements disposed along the housing for leak-tight engagement with the internal surface of a section with a changing profile of the downhole apparatus, which is descended through the axial flow passage of the downhole apparatus while maintaining a tight contact point during the entire time the device passes through the downhole apparatus. Above downhole cementing method comprises directing a volume of cement through a column containing a fracturing tool, directing the cement to the annulus, and lowering the downhole system through the column.

EFFECT: technical result is the improvement of the efficiency and reliability of tools.

36 cl, 9 dwg