Casing hanger assembly

Abstract

The present invention relates generally to a well casing hanger system that provides for orientation of a hanger with respect to a landing ring during installation. The shape of the mating features of the landing ring and hanger is such that rotation to a specific alignment will occur during installation if there is an initial rotational offset.

What is claimed is: 
     
         1 . A well casing hanger assembly for coupling and orienting a second well casing to a first well casing or a well cellar, the assembly comprising:
 a landing ring for attachment to a first well casing, conductor pipe or a well cellar, the landing ring having a first feature; and   a casing hanger for attachment to an external surface of a second well casing, the casing hanger having a second feature,
 wherein the second feature is configured to mate with the first feature whereby downward movement of the casing hanger causes the second feature to contact and mate with the first feature and continued downward movement of the casing hanger causes a rotational interaction between the mated first feature and second feature and resulting movement and alignment of the casing hanger in a predetermined orientation with respect to the landing ring. 
   
     
     
         2 . The well casing hanger assembly of  claim 1 ,
 wherein the first feature has a side that is not parallel to a longitudinal axis of the first well casing.   
     
     
         3 . The well casing hanger assembly of  claim 1 , further comprising:
 a plurality of features disposed on the landing ring,
 wherein each of the plurality of features are complementary in size and shape to the second feature, so that when the casing hanger is advanced towards the landing ring, the second feature engages the first feature or one of the plurality of features, thereby causing alignment of the casing hanger relative to the landing ring in one of several discrete rotational orientations.