Downhole pump seating nipple with perforations

Abstract

A pump seating nipple for retaining a downhole pump assembly in a fixed position within a production tubing string has a generally cylindrical body defining a nipple bore for receiving the downhole pump assembly. The pump seating nipple attaches to the production tubing string. At the bottom end of the body, the nipple bore is open to the bore of the production tubing string. An upper portion of the body surface engages a pump assembly seating cup. The body has a lower skirt which defines openings which allow gas flow from the nipple bore into the casing annulus.

What is claimed is: 
     
         1 . A pump seating nipple for retaining a pump assembly in a fixed and sealed position within a production tubing string disposed within a casing string to define a casing annulus therebetween, the pump seating nipple being insertable in the production tubing string and comprising:
 a substantially cylindrical body defining a nipple bore extending from a top end of the body to a bottom end of the body, wherein the body comprises an upper portion for receiving the pump assembly at least partially therein and a lower skirt which has an inside diameter larger than the pump assembly and which defines at least one opening extending through the lower skirt for fluid communication from the nipple bore to the casing annulus.   
     
     
         2 . The pump seating nipple of  claim 1  wherein the top end defines a top threaded surface for removable attachment of the top end to the upper joint, and the bottom end defines a bottom threaded surface for removable attachment of the bottom end to the lower joint. 
     
     
         3 . The pump seating nipple of  claim 1  wherein the body defines a chamfer between the top end of the body and an upper portion of an inner surface. 
     
     
         4 . The pump seating nipple of  claim 1  wherein the lower skirt has an internal diameter larger than the internal diameter of the upper portion of the body. 
     
     
         5 . The pump seating nipple of  claim 4  wherein the body defines a chamfer between the inside diameter of the upper portion and the inside diameter of the lower skirt. 
     
     
         6 . The pump seating nipple of  claim 1  wherein the at least one opening comprises a plurality of openings arranged in a plurality of columns or rows circumferentially spaced apart on the body. 
     
     
         7 . A downhole assembly adapted to be disposed within a casing string and comprising:
 (a) a production tubing string defining a production bore and disposed within the casing string to define a casing annulus therebetween;   (b) a downhole pump assembly disposed within the production bore comprising a barrel with a perforated fitting for fluid communication from the production bore into the barrel, and an attached resilient annular seating cup;   (c) a pump seating nipple disposed in the production tubing string, the pump seating nipple comprising a substantially cylindrical body comprising an outer surface, and an inner surface defining a nipple bore extending from a top end of the body to a bottom end of the body for receiving the downhole pump at least partially therein, wherein the nipple bore is in fluid communication with the production bore at the bottom end of the body;
 wherein the inner surface comprises an upper portion to engage the seating cup to resist relative movement between the downhole pump assembly and the body and to prevent gas migration between the downhole pump assembly and the body; and 
 wherein the body comprises a lower skirt having an inside diameter greater than a pump outside diameter and which defines at least one opening extending from a lower portion of the inner surface to the outer surface for fluid communication from the nipple bore to the casing annulus, wherein the at least one opening is disposed above the perforated fitting.