Drilling/frac adapter and method of use

Patent metadata

Field	Value
Publication number	US-8950485-B2
Application number	US-201113341703-A
Country	US
Kind code	B2
Filing date	Dec 30, 2011
Priority date	Jul 15, 2011
Publication date	Feb 10, 2015
Grant date	Feb 10, 2015

Abstract

A method of drilling and fracturing a well includes installing a drilling/frac adapter on a lower wellhead housing. The drilling/frac adapter has a higher internal pressure rating than the lower wellhead housing. The operator drills through the drilling/frac adapter to a desired depth, then runs and cements a casing string in the well. A lower packoff is installed in an annulus between the casing hanger and the lower wellhead housing and an upper packoff is set in an annulus between the drilling/frac adapter and the casing hanger. Frac fluid is pumped through the frac tree into the casing string at a higher pressure than the pressure rating of the lower housing but less than the pressure rating of the drilling/frac adapter. Then, the upper packoff and the drilling/frac adapter are removed from the lower housing and installing an upper wellhead housing on the lower wellhead housing.

First claim

The invention claimed is:

1. A method of drilling and fracturing a well, comprising:
(a) installing a drilling/frac adapter on a lower wellhead housing, the drilling/frac adapter having a higher internal pressure rating than the lower wellhead housing;
(b) drilling through the drilling/frac adapter to a desired depth, then running and cementing a casing string in the well, the casing string having a casing hanger located partly in the lower wellhead housing and partly in the drilling/frac adapter;
(c) installing a lower packoff in an annulus between the casing hanger and the lower wellhead housing and an upper packoff in an annulus between the drilling/frac adapter and the casing hanger;
(d) installing a frac tree on the drilling/frac adapter and pumping frac fluid through the frac tree into the casing string at a higher pressure than the pressure rating of the lower housing but less than the pressure rating of the drilling/frac adapter, the upper packoff isolating the lower wellhead housing from the pressure of the frac fluid; and
(e) removing the upper packoff and the drilling/frac adapter from the lower housing and installing an upper wellhead housing on the lower wellhead housing.

2. The method according to claim 1 , wherein:
the drilling/frac adapter has a valve port extending through a side wall; and wherein the method further comprises before step (b):
mounting a valve to the valve port, the valve having a pressure rating greater than the lower wellhead housing.

3. The method according to claim 2 , wherein:
in step (c) the upper packoff seals to the drilling/frac adapter below the valve port; and
during step (d) the frac fluid being pumped into the frac tree is in fluid communication with the valve port and the valve.

4. The method according to claim 1 , wherein step (d) further comprises installing a frac bushing on the upper packoff within the drilling frac/adapter.

5. The method according to claim 1 , wherein step (c) comprises running the upper and lower packoffs simultaneously.

6. The method according to claim 1 , wherein step (d) further comprises prior to pumping frac fluid, installing a protective sleeve within the upper packoff and casing hanger, and then pumping the frac fluid through the protective sleeve.

7. The method according to claim 6 , wherein the protective sleeve admits frac fluid being pumped to an annular clearance between the protective sleeve and the casing hanger.

8. The method according to claim 1 , further comprising:
installing a blowout preventer stack on the drilling/frac adapter before step (b);
after step (c) and before step (d), installing a retrievable plug in the casing hanger and removing the blowout preventer stack; and
retrieving the plug through the frac tree before pumping frac fluid through the frac tree in step (d).

9. The method according to claim 1 , further comprising:
after pumping frac fluid through the frac tree in step (d), installing a retrievable plug in the casing hanger before removing the frac tree in step (e).

10. The method according to claim 1 , further comprising:
inserting a wear bushing into the drilling/frac adapter before drilling in step (b); and
retrieving the wear bushing before running the casing string in step (b).

11. A method of drilling and fracturing a well, comprising:
(a) providing a drilling/frac adapter having a bore with an axis, a valve port extending laterally from the bore, and a valve mounted to the valve port;
(b) installing the drilling/frac adapter on a lower wellhead housing that has a lesser internal pressure rating than the drilling/frac adapter and the valve, then drilling through the drilling/frac adapter and the lower wellhead housing to a desired depth;
(c) running and cementing a casing string in the well, the casing string having a casing hanger landing in the lower wellhead housing and having an upper end within the bore of the drilling/frac adapter;
(d) installing a lower packoff in an annulus between the casing hanger and the lower wellhead housing and an upper packoff in an annulus between the drilling/frac adapter and the casing hanger below the valve port;
(e) installing a frac tree on the drilling/frac adapter and pumping frac fluid through the frac tree, the drilling/frac adapter, the casing hanger and into the casing string, the frac fluid exerting an internal pressure against the drilling/frac adapter, the casing hanger and the casing string, the upper packoff isolating the lower wellhead housing from the internal pressure of the frac fluid against against the lower wellhead housing; and
(f) removing the upper packoff and the drilling/frac adapter from the lower housing and installing an upper wellhead housing on the lower wellhead housing.

12. The method according to claim 11 , wherein step (e) further comprises installing a frac bushing on the upper packoff within the bore of the drilling frac/adapter.

13. The method according to claim 11 , wherein step (d) comprises running the upper and lower packoffs simultaneously.

14. The method according to claim 11 , wherein step (e) further comprises prior to pumping frac fluid, installing a protective sleeve within the upper packoff and the casing hanger, the protective sleeve having an inner diameter exposed to the pressure of the frac fluid being pumped.

15. The method according to claim 11 , further comprising:
installing a blowout preventer stack on the drilling/frac adapter before drilling in step (b);
after step (d) and before step (e), installing a retrievable plug in the casing hanger and removing the blowout preventer stack; and
retrieving the plug through the frac tree before pumping frac fluid through the frac tree in step (e).

16. The method according to claim 11 , further comprising:
after pumping frac fluid through the frac tree in step (e), installing a retrievable plug in the casing hanger before removing the frac tree in step (f).

17. The method according to claim 11 , further comprising:
inserting a wear bushing into the drilling/frac adapter before drilling in step (b); and
retrieving the wear bushing before running the casing string in step (c).

Assignees

• Wilkins Danny R
• Holtkamp Thomas H
• Smith Jerry D
• Ge Oil & Gas Pressure Control Lp

Inventors

• Wilkins Danny R
• Holtkamp Thomas H
• Smith Jerry D

Classifications

• E21B43/2607 Primary

  Surface equipment specially adapted for fracturing operations · CPC title

• E21B33/068

  having provision for introducing objects or fluids into, or removing objects from, wells (cementing-heads E21B33/05) · CPC title

• E21B43/26 Primary

  by forming crevices or fractures · CPC title