METHOD AND APPARATUS FOR FILTER WELL FORMING Russian patent published in 2005 - IPC

FIELD: mining industry, means used in the case of water production well completion during well boring or repair to prevent sand withdrawal from poorly consolidated or unconsolidated production bed.

SUBSTANCE: method of filter well forming involves installing filter column in well bore; pouring and flushing large formations of gravel filling, wherein the flushing is performed through at least two spraying devices. Directions of lower spraying device jets correspond to original slope angle of gravel filling in bed liquid. Directions of upper spraying device jets correspond to round curves so that cross-section of annular cavity between well bore and filter column is overlapped by changing jet curvature radii. Apparatus for filter well forming includes filter column with gravel filling, flushing tube with blocking means and check valve, and at least two spray devices installed between blocking means arranged on a body. The body is secured to flushing tube and has radial channels closed with spring-loaded radial valve. Check valve is pivotally connected to upper part of radial valve.

EFFECT: provision of optimal gravel distribution through the whole filtering zone, increased reliability and completeness of drill cuttings removal, improved gravel fractions distribution inside annular cavity.

3 cl, 1 ex, 1 dwg