Wellhead emission control system
A system for reducing methane emissions from a natural gas or oil wellhead. Some oil and gas wells leak a flow of natural gas, referred to as the surface casing vent flow. The system includes a catalytic oxidizing assembly operably connectable to the wellhead and configured to receive the surface casing vent flow therefrom. The catalytic oxidizing assembly includes a catalyst pad heated to a temperature sufficient to reduce the methane in the surface casing vent flow to carbon dioxide in the presence of oxygen. When the temperature and flow rate of the methane is sufficient, the heat generated by the exothermic oxidative reaction of the methane is sufficient to maintain the surface temperature of the catalyst pad, allowing the system to deactivate the heating element. The system can further include a separator configured to isolate a gas component of a surface casing vent flow when liquid is present.
1. A methane emission control system for a wellhead, comprising:
a catalytic oxidizing assembly operably connectable to the wellhead and configured to receive a surface casing vent flow therefrom, the catalytic oxidizing assembly including a catalyst pad and a heating element;
a pressure control valve configured to bypass the surface casing vent flow from the catalytic oxidizing assembly if a flow rate of the surface casing vent flow falls below a floor level, the floor level of the flow rate corresponding to a flow rate wherein exothermic oxidation of methane of the surface casing vent flow maintains a threshold temperature of the catalyst pads;
the catalyst pad including a material configured to oxidize methane; and
the heating element configured to heat the catalyst pad to the threshold temperature to initiate oxidation of methane of the surface casing vent flow.
2. A methane emission control system for a wellhead, comprising:
a catalytic oxidizing assembly operably connectable to the wellhead and configured to receive a surface casing vent flow therefrom, the catalytic oxidizing assembly including a catalyst pad and a heating element;
a pressure release valve configured to bypass the surface casing vent flow from the catalytic oxidizing assembly if a flow rate of the surface casing vent flow exceeds a ceiling level;
the catalyst pad including a material configured to oxidize methane; and
the heating element configured to heat the catalyst pad to a threshold temperature to initiate oxidation of methane of the surface casing vent flow.
3. A wellhead system for reducing methane emissions, comprising:
a surface casing vent
a catalytic oxidizing assembly operably connected to the surface casing vent and configured to receive a surface casing vent flow therefrom, the catalytic oxidizing assembly including a catalyst pad and a heating element;
a pressure control valve configured to bypass the surface casing vent flow from the catalytic oxidizing assembly if a flow rate of the surface casing vent flow falls below a floor level, the floor level of the flow rate corresponding to a flow rate wherein exothermic oxidation of methane of the surface casing vent flow maintains a threshold temperature of the catalyst pad;
the catalyst pad including a material configured to oxidize methane; and
the heating element configured to heat the catalyst pad to the threshold temperature to initiate oxidation of methane of the surface casing vent flow.
4. A wellhead system for reducing methane emissions, comprising:
a surface casing vent;
a catalytic oxidizing assembly operably connected to the surface casing vent and configured to receive a surface casing vent flow therefrom, the catalytic oxidizing assembly including a catalyst pad and a heating element;
a pressure release valve configured to bypass the surface casing vent flow from the catalytic oxidizing assembly if a flow rate of the surface casing vent flow exceeds a ceiling level;
the catalyst pad including a material configured to oxidize methane; and
the heating element configured to heat the catalyst pad to a threshold temperature to initiate oxidation of methane of the surface casing vent flow.
5. The methane emission control system of claim 1 , further comprising a separator operably connectable to the wellhead in series with the catalytic oxidizing assembly, the separator configured to isolate a gas component from a liquid component of the surface casing vent flow.
6. The methane emission control system of claim 1 , wherein the heating element is configured to heat the catalyst pad to at least 150° C.
7. The methane emission control system of claim 1 , wherein the catalytic oxidizing assembly is connectable to a surface casing vent of the wellhead via piping.
8. The methane emission control system of claim 1 , wherein the material of the catalyst pad is selected from a group consisting of platinum and palladium.
9. The methane emission control system of claim 1 , wherein the catalytic oxidizing assembly is contained within a housing.
10. The methane emission control system of claim 9 , wherein the housing is watertight.
11. The methane emission control system of claim 1 , wherein the catalytic oxidizing assembly is supported aloft via a stand.
12. The methane emission control system of claim 2 , further comprising a separator operably connectable to the wellhead in series with the catalytic oxidizing assembly, the separator configured to isolate a gas component from a liquid component of the surface casing vent flow.
13. The methane emission control system of claim 2 , wherein the heating element is configured to heat the catalyst pad to at least 150° C.
14. The methane emission control system of claim 2 , wherein the catalytic oxidizing assembly is connectable to a surface casing vent of the wellhead via piping.
15. The methane emission control system of claim 2 , wherein the material of the catalyst pad is selected from a group consisting of platinum and palladium.
16. The methane emission control system of claim 2 , wherein the catalytic oxidizing assembly is contained within a housing.
17. The methane emission control system of claim 16 , wherein the housing is watertight.
18. The methane emission control system of claim 2 , wherein the catalytic oxidizing assembly is supported aloft via a stand.
19. The wellhead system of claim 3 , further comprising a separator operably connected to the wellhead in series with the catalytic oxidizing assembly, the separator configured to isolate a gas component from a liquid component of the surface casing vent flow.
20. The wellhead system of claim 3 , wherein the heating element is configured to heat the catalyst pad to at least 150° C.
21. The wellhead system of claim 3 , wherein the catalytic oxidizing assembly is connectable to the surface casing vent of the wellhead via piping.
22. The wellhead system of claim 3 , wherein the material of the catalyst pad is selected from a group consisting of platinum and palladium.
23. The wellhead system of claim 3 , wherein the catalytic oxidizing assembly is contained within a housing.
24. The wellhead system of claim 23 , wherein the housing is watertight.
25. The wellhead system of claim 3 , wherein the catalytic oxidizing assembly is supported aloft via a stand.
26. The wellhead system of claim 4 , further comprising a separator operably connected to the wellhead in series with the catalytic oxidizing assembly, the separator configured to isolate a gas component from a liquid component of the surface casing vent flow.
27. The wellhead system of claim 4 , wherein the heating element is configured to heat the catalyst pad to at least 150° C.
28. The wellhead system of claim 4 , wherein the catalytic oxidizing assembly is connectable to the surface casing vent of the wellhead via piping.
29. The wellhead system of claim 4 , wherein the material of the catalyst pad is selected from a group consisting of platinum and palladium.
30. The wellhead system of claim 4 , wherein the catalytic oxidizing assembly is contained within a housing.
31. The wellhead system of claim 30 , wherein the housing is watertight.
32. The wellhead system of claim 4 , wherein the catalytic oxidizing assembly is supported aloft via a stand.