Prepacked well screen and casing assembly

摘要

Prepacked well screen and casing assembly for use in wells provides very substantial savings in the expense and time required to complete a well as compared to the conventional techniques of down-hole perforating and gravel packing. The assembly includes an external casing or liner member which would be provided with a large number of perforations during manufacture. A pipe base screen jacket assembly is positioned concentrically within the casing and attached to it by readily machinable upper and lower annular ring members. The hollow cylindrical annulus between the screen and casing is filled with a resin-coated gravel pack material which is cured after the fill operation to maintain its integrity. The assembly can be hung in the uncased producing zone of a new well by a liner hanger or could be placed in an existing cased well which is to be reworked by first milling away the existing casing in the production zone. If reworking of the well should ever be required, a washover tool can be used to remove the annular ring members so that the screen jacket assembly could be replaced or repacked by conventional techniques.