Wellhead completion assembly capable of versatile arrangements

Abstract

A wellhead completion assembly has a head connected to surface casing. A rotatable flange or the like can be used to connect various components to a threaded end of the head. A casing hanger installs in the head, and the hanger's upper end extends beyond the head's top edge. This exposed end has an external threaded connection to connect to various wellhead components using a rotatable flange or the like. For example, a locking ring can threadably connect to the head's threaded end to support the hanger in the head. Then, a rotatable flange can threadably connect to the hanger's exposed end so that another component, such as a completion spool or gate valve, can nippled up directly to the hanger. When the hanger is fluted, a pack-off assembly can allow testing off inner and outer sealing integrity via a test port accessible through an opening in the locking ring.

What is claimed is: 
     
       1. wellhead completion assembly, comprising:
 a casing head connecting to casing at a wellhead and having a first external threaded connection adjacent a first end; 
 a casing hanger landing in the casing head and having a shoulder and a second end, the second end extending beyond the first end of the casing head and having a second external threaded connection, the second external threaded connection connectable to a connector to support at least one additional component above the casing hanger; 
 a pack-off plate disposed on the second end of the casing hanger adjacent the shoulder, the pack-off plate having an upper surface, an inner portion, and an outer portion, the inner portion sealable sealably engaging an external surface of the casing hanger, the outer portion sealable sealably engaging an internal surface of the casing head; and 
 a head ring threadably connecting to the first external threaded connection of the casing head and defining an opening through which the second end of the casing hanger extends, a portion of the head ring directly engaging the upper surface of the pack-off plate. 
 
     
     
       2. The assembly of  claim 1 , wherein the pack-off plate comprises:
 a first pair of sealing seats on the outer portion, 
 a second pair of sealing seats on the inner portion, and 
 a test port defined in the upper surface and accessible through the opening in the head ring, the test port communicating with the inner and outer portions between the first and second pairs of sealing seats. 
 
     
     
       3. The assembly of  claim 1 , wherein the casing head comprises a single-bowl arrangement defining an internal shoulder within an internal bore, the casing hanger landing on the internal shoulder to be supported therein. 
     
     
       4. The assembly of  claim 1 , wherein the casing head comprises a double-bowl arrangement defining an internal shoulder within an internal bore, the casing hanger landing on one or more components supported by the internal shoulder. 
     
     
       5. The assembly of  claim 1 , wherein the casing hanger defines at least one flute, and wherein the pack-off plates plate seals fluid communication through the at least one flute. 
     
     
       6. The assembly of  claim 1 , further comprising a hanger ring positionable about the external surface of the casing hanger, and wherein the pack-off plate comprise a lip positionable in wedged engagement between the hanger ring and a portion of the external surface of the casing hanger. 
     
     
       7. The assembly of  claim 4 , wherein the casing head for the double-bowl arrangement comprises at least two head components interconnectable to one another, a first of the head components having the internal shoulder therein, a second of the head components having the first external threaded connection to which the head ring threadably connects. 
     
     
       8. The assembly of  claim 6 , wherein the inner portion of the pack-off plate threadably connects to a third threaded connection on the external surface of the casing hanger. 
     
     
       9. A wellhead completion assembly, comprising:
 a casing head connecting to a first casing and having a first external threaded connection adjacent a first end, the casing head comprising a double-bowl arrangement defining an internal shoulder within an internal bore; 
 a casing hanger landing on one or more other components supported by the internal shoulder of the casing head, the casing hanger defining at least one flute and having a shoulder and a second end, the second end extending beyond the first end of the casing head and having a second external threaded connection, the second external threaded connection connectable to a connector to support at least one additional component above the casing hanger; 
 a head ring threadably connecting to the first external threaded connection of the casing head and defining an opening through which the second end of the casing hanger extends; and 
 at least one pack-off component positioning positioned between the shoulder of the casing hanger and a portion of the head ring, the at least one pack-off component sealably engaging an external surface of the casing hanger and sealably engaging an internal surface of the casing head, the at least one pack-off component sealing fluid communication through the at least one flute in the casing hanger. 
 
     
     
       10. The assembly of  claim 9 , wherein the casing head for the double-bowl arrangement comprises at least two head components interconnectable to one another, a first of the head components having the internal shoulder therein, a second of the head components having the first external threaded connection to which the head ring threadably connects. 
     
     
       11. The assembly of  claim 9 , wherein the at least one pack-off component comprises a pack-off plate having—
 an inner portion threadably connecting to a third threaded connection on the external surface of the casing hanger, and 
 an outer portion sealably engaging the internal surface of the casing head. 
 
     
     
       12. The assembly of  claim 11 , wherein the at least one pack-off component comprises a hanger ring positionable about the external surface of the casing hanger, and wherein the pack-off plate comprise a lip positionable in wedged engagement between the hanger ring and a portion of the external surface of the casing hanger. 
     
     
       13. The assembly of  claim 9 , wherein the at least one pack-off component comprises a pack-off plate having—
 a first pair of sealing seats on an outer portion, 
 a second pair of seals sealing seats on an inner portion, and 
 a test port defined in an upper surface of the plate and accessible through the opening in the head ring, the test port communicating with the outer portion between the first pair of sealing seats and communicating with the inner portion between the second pair of sealing seats. 
 
     
     
       14. A system for a wellhead completion assembly, comprising:
 a first head component having one end connectable to casing at a wellhead and having a first external threaded connection adjacent another end; and 
 second head components each having second an internal threaded connections connection adjacent one end and having a second external threaded connections connection adjacent another end, the second each internal threaded connection connectable to the first external threaded connection on the first head component, the second internal and external threaded connections of each of the second head components being complementary and threadably interconnectable to one another, 
 wherein the first head component is Used independently on the wellhead for a single-bowl arrangement of the wellhead completion assembly, 
 wherein one of the second head components is used in conjunction with the first head component for a first multiple-bowl arrangement of the wellhead completion assembly, the second internal threaded connection of the one second head component connecting to the first external threaded connection on the first head component to stack the one second head component on top of the first head component; and 
 wherein two or more of the second head components are used in conjunction with the first head component for second multiple-bowl arrangements of the wellhead completion assembly, the second internal and external threaded connections of the second head components interconnecting to one another to stack the two or more second head components on top of one another, the internal threaded connection of a lowermost one of the second head components connecting to the first external threaded connection on the first head component to stack the second head components on top of the first head component. 
 
     
     
       15. The system for the assembly of  claim 14 , further comprising:
 a casing hanger supported supportable in the wellhead completion assembly, the casing hanger having a distal end extending beyond the first head component in the single-bowl arrangement or beyond a topmost end one of the second head components in the multiple-bowl arrangements of the wellhead completion assembly, the distal end having an external threaded connection connectable to a connector to support at least one additional component above the casing hanger; and 
 a head ring threadably connectable to the first external threaded connection on the first head component in the single-bowl arrangement or threadably connectable to the second external connection of a topmost one of the second head components in the multi-bowl arrangement multiple-bowl arrangements, the head ring defining an opening through which the distal end of the casing hanger extends. 
 
     
     
       16. The system for the assembly of  claim 15 , wherein a portion of the head ring directly engages a shoulder of the casing hanger, and wherein the casing hanger comprises—
 a pair of sealing seats on an outer surface, and 
 a test port defined in the shoulder and accessible through the opening in the head ring, the test port communicating between the pair of sealing seats. 
 
     
     
       17. The system for the assembly of  claim 15 , further comprising a pack-off plate disposed in the topmost end one of the wellhead completion assembly head components between the casing hanger and a portion of the head ring, wherein the pack-off plate comprises:
 an upper surface positioning adjacent the portion of the head ring; 
 an inner portion engaging an external surface of the casing hanger, and 
 an outer portion engaging an internal surface of the wellhead completion assembly. 
 
     
     
       18. The system for the assembly of  claim 17 , wherein the pack-off plate comprises:
 a first pair of sealing seats on the outer portion, 
 a second pair of sealing seats on the inner portion, and 
 a test port defined in the upper surface and accessible through the opening in the head ring, the test port communicating with the inner and outer portions between the first and second pairs of sealing seats. 
 
     
     
       19. The system for the assembly of  claim 14 , further comprising:
 a hub threading on the first external threaded connection of the first head component in the single-bowl arrangement or threading on the second external threaded connection of the topmost one of the second head components in the multi-bowl multiple-bowl arrangements; and 
 an adapter disposing disposed on the an end of one the first or second head component components and locking to the hub, the adapter connecting connectable to at least one additional component above the wellhead assembly. 
 
     
     
       20. The system for the assembly of  claim 14 , wherein in the first and second multiple-bowl arrangements, the one or more second head components are removable from the first head component to expose an end of a stuck pipe in the wellhead completion assembly; and wherein a rotatable flange connects to the first external threaded connections of the first head component to support one or more additional components above the first head component. 
     
     
       21. A hanger pack-off assembly, comprising:
 a casing hanger positionable in a casing head and having a first external threaded connection about an external surface; 
 a hanger ring positionable about the external surface of the casing hanger; and 
 a pack-off plate defining an a first opening through first and second sides of the plate, the first opening having a first internal threaded connection threading onto the first external threaded connection on the casing hanger, an outer surface of the plate having a first pair of sealing seats formed thereabout, an inner surface of the plate having a second pair of sealing seats formed thereabout, a test port defined in the first side of the plate and communicating with the inner and outer surfaces between the first and second pairs of sealing seats, the pack-off plate comprising a lip positionable in wedged engagement between the hanger ring and a portion of the external surface of the casing hanger. 
 
     
     
       22. The assembly of  claim 21 , further comprising a head ring threadably connecting connectable to the casing head and defining an a second opening therethrough, wherein the casing hanger has a distal end extending through the second opening, the distal end having a second external threaded connection to which a component connects to the casing hanger. 
     
     
       23. A wellhead completion method, comprising:
 connecting a casing head to surface casing; 
 landing a casing hanger in the casing head to support production casing in the surface casing such that an upper end of the casing hanger extends beyond an upper end of the casing head; 
 disposing a pack-off plate on the upper end of the casing hanger, the pack-off plate sealably engaging an external surface of the casing hanger and sealably engaging an internal surface of the casing head; 
 threadably connecting a head ring on the upper end of the casing head and directly engaging an upper surface of the pack-off plate with the head ring, the upper end of the casing head fitting through an opening of the head ring; 
 threading a connector to the upper end of the casing hanger; and 
 connecting an additional component above the casing hanger by connecting to the connector. 
 
     
     
       24. The method of  claim 23 , wherein disposing the pack-off plate on the upper end of the casing hanger comprises threading an inside portion of the pack-off plate on external thread threads on the upper end of the casing hanger. 
     
     
       25. The method of  claim 23 , wherein disposing the pack-off plate on the upper end of the casing hanger comprises sealing an inner pair of seals on the pack-off plate against the external surface of the casing hanger and sealing an outer pair of seals on the pack-off plate against the internal surface of the casing head. 
     
     
       26. The method of  claim 25 , further comprising testing the inner and outer pairs of seals via a test port defined in the upper surface of the pack-off plate and accessible through the opening in the head ring. 
     
     
       27. The method of  claim 23 , wherein disposing the pack-off plate on the upper end of the casing hanger comprises:
 wedging a lip on the pack-off plate between a hanger ring and the external surface of the casing hanger, and 
 engaging the hanger ring against the internal surface of the casing head. 
 
     
     
       28. The method of  claim 23 , wherein threading the connector to the upper end of the casing hanger comprises threading a rotatable flange to the upper end of the casing hanger. 
     
     
       29. The method of  claim 28 , wherein connecting the additional component above the casing hanger comprises connecting a gate valve for a facing operation to the rotatable flange. 
     
     
       30. The method of  claim 23 , wherein before threadably connecting the head ring, threading the connector to the upper end of the casing hanger, and connecting the additional component above the casing hanger, the method comprises initially removing a blow out preventer stack and a first rotatable flange from the casing head, the first rotatable flange being threaded on an external thread on the casing head. 
     
     
       31. The method of  claim 30 , wherein the first rotatable flange is rated for a first working pressure, and wherein the connector threading to the upper end of the casing hanger comprises a second rotatable flange having a second working pressure greater than the first working pressure. 
     
     
       32. The method of  claim 23 , wherein landing the casing hanger comprises passing the casing hanger on a running tool through a blow out preventer stack installed on the casing head. 
     
     
       33. A wellhead completion assembly, comprising:
 a casing head connecting to casing at a wellhead and having a first external threaded connection adjacent a first end; 
 a casing hanger landing in the casing head and having a second end and a shoulder, the casing hanger comprising a pair of sealing seats on an outer surface and comprising a test port defined in the shoulder, the test port communicating between the pair of sealing seats, the second end extending beyond the first end of the casing head and having a second external threaded connection, the second external threaded connection connectable to a connector to support at least one additional component above the casing hanger; and 
 a head ring threadably connecting to the first external threaded connection of the casing head and defining an opening through which the second end of the casing hanger extends, a portion of the head ring directly engaging the shoulder on the casing hanger, the test port in the shoulder of the casing hanger being accessible through the opening in the head ring. 
 
     
     
       34. The assembly of  claim 33 , wherein the casing head comprises a single-bowl arrangement defining an internal shoulder within an internal bore, the casing hanger landing on the internal shoulder to be supported therein. 
     
     
       35. The assembly of  claim 33 , wherein the casing head comprises a double-bowl arrangement defining an internal shoulder within an internal bore, the casing hanger landing on one or more components supported by the internal shoulder. 
     
     
       36. The assembly of  claim 35 , wherein the casing head for the double-bowl arrangement comprises and at least two head components interconnectable to one another, a first of the head components having the internal shoulder therein, a second of the head components having the first external threaded connection to which the head ring threadably connects. 
     
     
       37. A wellhead completion assembly, comprising:
 a casing head connecting to a first casing and having a first external threaded connection adjacent a first end, the casing head comprising a double-bowl arrangement defining an internal shoulder within an internal bore; 
 a casing hanger landing on one or more other components supported by the internal shoulder of the casing head, the casing hanger having a shoulder and a second end, the second end extending beyond the first end of the casing head and having a second external threaded connection, the second external threaded connection connectable to a connector to support at least one additional component above the casing hanger; 
 a head ring threadably connecting to the first external threaded connection of the casing head and defining an opening through which the second end of the casing hanger extends; 
 a hanger ring positionable about an external surface of the casing hanger; and 
 a pack-off plate positioning positioned between the shoulder of the casing hanger and a portion of the head ring, the pack-off plate having an inner portion threadably connecting to a third threaded connection on the external surface of the casing hanger, the pack-off plate having an outer portion sealably engaging an internal surface of the casing head, the pack-off plate comprising a lip positionable in wedged engagement between the hanger ring and a portion of the external surface of the casing hanger. 
 
     
     
       38. The assembly of  claim 37 , wherein the casing head for the double-bowl arrangement comprises and at least two head components interconnectable to one another, a first of the head components having the internal shoulder therein, a second of the head components having the first external threaded connection to which the head ring threadably connects. 
     
     
       39. The assembly of  claim 37 , wherein the casing hanger defines at least one flute, and wherein the at least one pack-off plate seals fluid communication through the at least one flute. 
     
     
       40. The assembly of  claim 37 , wherein the pack-off plate comprises—
 a first pair of sealing seats on the outer portion, 
 a second pair of seals sealing seats on the inner portion, and 
 a test port defined in an upper surface of the plate and accessible through the opening in the head ring, the test port communicating with the outer portion between the first pair of sealing seats and communicating with the inner portion between the second pair of sealing seats.