Installation assembly for a subsea wellhead

Abstract

A system for load transfer from a wellhead to the sea bed adjacent a subsea well, including a suction pile for securing to the sea bed, and a wellhead housing assembly having a longitudinal axis and attached to the suction pile, the wellhead housing for subjection to an axial load acting in a direction parallel to the longitudinal axis, and a bending load acting in a direction not parallel to the longitudinal axis. The system further includes a suction pile connector that transmits the axial load and the bending load from the wellhead housing through the suction pile toward the sea bed, and that is attached to the suction pile, the suction pile connector engaged with the wellhead housing to substantially maintain the relative positions of the wellhead housing and the suction pile.

That claimed is: 
     
         1 . A system for load transfer from a wellhead to the sea bed adjacent a subsea well, comprising:
 a suction pile for securing to the sea bed;   a wellhead housing having a longitudinal axis and attached to the suction pile, the wellhead housing for subjection to an axial load acting in a direction parallel to the longitudinal axis; and   a suction pile connector that transmits the axial load from the wellhead housing through the suction pile toward the sea bed, and that is attached to the suction pile, the suction pile connector engaged with the wellhead housing to substantially maintain the relative positions of the wellhead housing and the suction pile.   
     
     
         2 . The system of  claim 1 , wherein the suction pile connector substantially circumscribes the wellhead housing and has an inner surface defining a recess, and wherein the suction pile connector further comprises a dog connector positioned in the recess and movable toward the longitudinal axis of the wellhead housing into engagement with the wellhead housing to restrict relative axial movement between the suction pile connector and the wellhead housing. 
     
     
         3 . The system of  claim 2 , wherein the dog connector has teeth extending toward the wellhead housing to engage the wellhead housing. 
     
     
         4 . The system of  claim 3 , wherein the wellhead housing has an outer surface with ridges positioned to correspond to the teeth so that when the dog connector moves into engagement with the wellhead housing, the teeth of the dog connector engage the ridges of the wellhead housing. 
     
     
         5 . The system of  claim 4 , wherein the teeth of the dog connector each have a lower surface, and the ridges of the wellhead housing each have an upper surface, and when the axial load is applied to the system, the lower surfaces of the teeth engage with the upper surfaces of the ridges so that the axial load is transmitted from the wellhead housing to the suction pile connector through the dog connector. 
     
     
         6 . The system of  claim 2 , wherein the dog connector is hydraulically actuated. 
     
     
         7 . The system of  claim 2 , wherein the dog connector is mechanically actuated. 
     
     
         8 . A system for load transfer from a wellhead to the sea bed adjacent a subsea well, comprising:
 a suction pile for securing to the sea bed;   a wellhead housing having a longitudinal axis and attached to the suction pile, the wellhead housing for subjection to a bending load acting in a direction not parallel to the longitudinal axis; and   a suction pile connector that transmits the bending load from the wellhead housing through the suction pile toward the sea bed, and that is attached to the suction pile, the suction pile connector engaged with the wellhead housing to substantially maintain the relative positions of the wellhead housing and the suction pile.   
     
     
         9 . The system of  claim 8 , wherein the wellhead housing has an outer surface with an outwardly directed shoulder. 
     
     
         10 . The system of  claim 9 , wherein the suction pile connector has an inner surface with an inwardly directed shoulder positioned to correspond to the outwardly directed shoulder of the outer surface of the wellhead housing. 
     
     
         11 . The system of  claim 10 , wherein when the bending load is applied to the wellhead housing, rotational movement of the wellhead housing relative to the suction pile connector is restricted by engagement of the outwardly directed shoulder of the outer surface of the wellhead housing with the inwardly directed shoulder of the suction pile connector. 
     
     
         12 . The system of  claim 10 , wherein the wellhead housing is subjected to an axial load acting in a direction parallel to the longitudinal axis, and the suction pile connector transmits the axial load from the wellhead housing through the suction pile toward the sea bed. 
     
     
         13 . The system of  claim 12 , wherein the suction pile connector substantially circumscribes the wellhead housing and has an inner surface defining a recess, and wherein the suction pile connector further comprises a dog connector positioned in the recess and movable toward the longitudinal axis of the wellhead housing into engagement with the wellhead housing to restrict relative axial movement between the suction pile connector and the wellhead housing. 
     
     
         14 . The system of  claim 13 , wherein the dog connector has teeth extending toward the wellhead housing to engage the wellhead housing, and the wellhead housing has an outer surface with ridges positioned to correspond to the teeth. 
     
     
         15 . The system of  claim 14 , wherein when the bending load is applied to the wellhead housing, rotational movement of the wellhead housing relative to the suction pile connector is restricted by engagement of the outwardly directed shoulder of the outer surface of the wellhead housing with the inwardly directed shoulder of the suction pile connector, and the teeth of the dog connector do not contact the ridges of the wellhead connector. 
     
     
         16 . A method of transmitting a load from well equipment to a sea floor, the method comprising:
 a) coupling the well equipment to a suction pile using a suction pile connector, the suction pile connector defining a recess with a dog connector, the dog connector having at least one tooth for engagement with the well equipment;   b) transmitting an axial load from the well equipment to the dog connector via the tooth of the dog connector;   c) transmitting the axial load from the dog connector to the suction pile connector;   d) transmitting the axial load from the suction pile connector to the suction pile; and   e) transmitting the axial load from the suction pile to the sea floor.   
     
     
         17 . The method of  claim 16 , wherein the well equipment has a shoulder and the suction pile connector has a corresponding shoulder, the method further comprising:
 transmitting a bending load from the well equipment to the suction pile connector via the well equipment shoulder and the suction pile connector shoulder.   
     
     
         18 . The method of  claim 17 , further comprising:
 transmitting the bending load from the suction pile connector to the suction pile; and   transmitting the bending load from the suction pile to the sea floor.   
     
     
         19 . The method of  claim 16 , further comprising:
 f) prior to step b), driving the at least one tooth of the dog connector into engagement with the well equipment using hydraulic or mechanical force.   
     
     
         20 . The method of  claim 19 , wherein the well equipment at least one ridge on an outer surface thereof, and step f) further comprises:
 driving the at least one tooth of the dog connector into engagement with the at least one ridge of the outer surface of the well equipment.