Well screen fitting and method of sealing same to a casing

Claim 1

In combination, a well casing and a well screen fitting for sealing a well screen to the interior surface of said well casing through which it is moved to its final position, said well screen fitting comprising an elongated cylindrical body member having a recess in one end for receiving a well screen, a circumferential groove in the wall of the body at a position spaced axially from said recess, a generally V-shaped flexible sealing ring having a base portion and inner and outer wall portions extending upwardly from said base portion, said sealing ring being positioned along its entire axial extent in said groove with said base portion located at the end of the groove closest to the recess, the inner wall portion of the ring having its inner surface in tight engagement with the inner wall of the groove throughout the length thereof and the outer wall portion of the ring being formed so as to extend outwardly in a skirt-like fashion relative to the outer surface of the fitting, the combined wall thickness of said inner and outer wall portions being between 70-80% of the radial distance between the inner wall of the circumferential groove and the inner wall of the well casing, the outer wall portion of the ring being of sufficient resiliency and axial extent that it will fold over on itself and be compressed when the fitting and sealing ring are moved a short distance in said well casing in the direction opposite to that used for installing the fitting into the casing.