Integral well filter and screen and method for making and using same

Abstract

An integral well filter and screen and a method for making and using it are described. A first embodiment includes a perforated cylindrical well screen with a filter assembly in its interior. The filter assembly includes a pliable filter material bonded to a filter support. The filter support is a plastic lattice rigid enough to hold the shape of the filter assembly and keep the filter material in contact with the inner surface of the well screen, yet deformable enough that the filter assembly can be formed into a shape consistent with the interior of the well screen. A second embodiment includes a well screen with a filter made of a rigid, porous material placed inside the well screen. Because the filter is rigid, it needs no filter support. Methods of manufacturing each of the embodiments are presented. For the first embodiment, the method includes bonding the filter support to the filter material; forming the filter assembly into a cylindrical shape complementary to the inner surface of the well screen; securing abutting edges of the filter assembly to maintain its shape and rigidity, and ensure complete filtration, and inserting the filter assembly into the well screen. The manufacture of the filter in the second embodiment is similar, but does not include the bonding of a filter support to the rigid, porous material. Finally, a method of installing the filter and screen in a horizontal well is presented.