METHOD FOR SEALING-AND-UNSEALING HOLLOW PLUG SECURING IN CIRCULATION ORIFICES OF WIRE-BASED WELL SCREEN BODY WITHOUT THREAD USAGE Russian patent published in 2007 - IPC E21B43/08 

FIELD: oil refinery industry, particularly downhole oil and gas production equipment, namely wire-based well screens.

SUBSTANCE: method involves boring circulation orifices having predetermined shapes in well screen body; producing sealing-and-unsealing plugs conformed to the shape of the circulation orifices and having thimble-shaped hollow bottoms; inserting hollow plugs in circulation orifices of well screen body; retaining plugs in the circulation orifices. Circulation orifices are provided with two-stage smooth cylindrical surfaces arranged so that orifice surface parts having larger diameters are located from outer body side. Plug also has two-stage smooth cylindrical surface with surface part having larger diameter located from plug orifices. Hollow plugs are freely inserted well screen body orifices as far as they abut against ledge of lower orifice stage so that plug end projects from well screen body wall for predetermined length. The predetermined length is defined by reference hairline made in plug surface. Upper plug end having opened orifice is within body orifice and distance between upper plug end and body surface ΔS=S₀-S_l, where S₀ is depth of orifice stage having larger diameter and S_l is depth of hollow plug stage having larger diameter. Plugs are fixed in well screen body orifices by local plastic deformation method. Local plastic deformation method involves applying pressing tool action to upper well screen body surface in orifice zone so that body metal encloses plug surface touching the body and metal covers opened plug end. Plugs are secured to well screen body orifices by local plastic deformation method where pressing tool acts simultaneously on plug orifice sides and opened ends thereof so that plug metal snugly fits contact surface of well screen body.

EFFECT: decreased labor inputs for well screen production and decreased plug metal consumption.

8 cl, 5 dwg