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Kelly, Shaheerah

From: Dwight Mallory <Dmallory@resoluteenergy.com>

Sent: Thursday, October 08, 2015 1:36 PM

To: Kelly, Shaheerah

Subject: RE: MCU PSD Permit

Attachments: removed.txt

It is the same.

The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location.

Dwight E. Mallory 

Environmental/Regulatory Manager 

Resolute Energy Corporation 

1700 Lincoln Street, Suite 2800 

Denver, CO 80203 

Direct: 303-573-4886 X 1165 

From: Kelly, Shaheerah [mailto:Kelly.Shaheerah@epa.gov]  

Sent: Thursday, October 08, 2015 2:34 PM

To: Dwight Mallory <Dmallory@resoluteenergy.com>

Subject: Re: MCU PSD Permit

Dwight,

Please confirm whether "McElmo Creek Unit Gas Reinjection Facility" as used in the O&M Plan is the same as 

the "MCU Gas Compression Plant".

Thanks.

From: Dwight Mallory <Dmallory@resoluteenergy.com>

Sent: Wednesday, October 7, 2015 1:28 PM

To: Kelly, Shaheerah

Subject: RE: MCU PSD Permit  

  

Shaheerah,

I did confirm that the reason the Acid Gas B compressor does not have a separate maintenance table in the maintenance

plan is because it is a small machine that is only used for back up capacity and isn’t designed to be part of the primary

process train at the facility. Section III of the O&M Plan contains language to that affect and I modified the highlighted

paragraph below. I also corrected a typo that indicated that Acid Gas A was being used for backup (it should read Acid

Gas B  is a smaller unit...).

I attached a later revision of the O&M Plan. It should be the same as the copy you have except that I cleaned up a few

typos and grammar issues.

Please let me know if I can be of further assistance.
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1.1 Inlet Separation 

The inlet separation consists of an inlet slug receiver which collects free liquids. The gas then passes through 

filter vessels which collect any incoming solids.

1.2 Compression 

The gas compression plant houses the following five (5) compressors:

Compressor Operating Status

Acid Gas A Nonoperational

Acid Gas B Operational

Aerial C-5 Operational

HOS-4 Operational

HOS-6 Operational

Acid Gas B, Aerial C-5, HOS-4, and HOS-6 are high-speed electrically-driven reciprocating compressors. 

Aerial C-5, HOS-4, and HOS-6 are the primary facility compressors. 

Acid Gas B is a smaller unit and is only used for backup and excess throughput. Acid Gas A is non-functioning 

and uneconomical to return to service. It remains at the plant as a source of spare parts for the Acid Gas B 

compressor.

The compressors provide approximately 8,000 combined brake horsepower (BHP) and each compressor 

consists of four or five compression stages which raise the pressure of the incoming gas from 40 psig to 2,900 

psig. Each stage has a dedicated aerial cooler and liquid scrubber vessel. Inter stage dehydration takes place to 

remove water for corrosion mitigation on the HOS 6 compressor. 

Operations, maintenance and isolation procedures for Ariel C-5, HOS 4, and HOS 6 compressors are 

included in this appendices of this O&M Plan. Operating and isolation procedures are included for the 

Acid Gas B compressor. However, a separate maintenance table has not been developed for the Acid Gas 

B compressor because it is only capable of handling 1.6 MMCF/day and was never intended to be part of 

the primary process train at the facility.

1.3 Re-Injection 

The compressor units discharge into a single header, where purchased carbon dioxide (CO2) is co-mingled to 

achieve a daily injection rate of up to 24 MMSCFD. The gas is then distributed to the field. 

During gas compression plant upsets or compressor downtime events, a portion or all of the inlet volume to the 

gas compression plant is automatically diverted to flare until the problem is corrected.

The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location.

Dwight E. Mallory

Environmental/Regulatory Manager

Resolute Energy Corporation

1700 Lincoln Street, Suite 2800

Denver, CO 80203

Direct: 303-573-4886 X 1165
3

From: Kelly, Shaheerah [mailto:Kelly.Shaheerah@epa.gov]  

Sent: Wednesday, October 07, 2015 11:30 AM

To: Dwight Mallory <Dmallory@resoluteenergy.com>

Subject: MCU PSD Permit

  

Dwight,

  

Per our phone call, below is the revised section of the O&M plan. You mentioned that the Acid Gas B unit was a standby

unit.  It would be helpful if you would send me a statement or sentence that describes the use of the Acid Gas B unit so

we can better describe in below. Additionally, feel free to send me any corrections to the revised section below.  

  

Thanks.

  

1. PROCESS OVERVIEW & OPERATING PROCEDURES

The McElmo Creek Unit Oil Production Facility (MCU Facility) gas compression plant serves tertiary recovery 

operations for the McElmo Creek Field. The gas compression plant receives produced gas through a gathering 

system, pressures the gas up to a suitable working pressure then re-injects the gas to maintain reservoir pressure. 

The natural gas is injected with produced water in a dual injection system. Due to varying water injection 

demands in the field, and to the number of wells being serviced at any time, the gas compression plant inlet 

volume can vary between 10 and 24 million standard cubic feet per day (MMSCFD).

The gas is processed in three main steps: inlet separation, compression and re-injection.

1.1 Inlet Separation 

The inlet separation consists of an inlet slug receiver which collects free liquids. The gas then passes through 

filter vessels which collect any incoming solids.

1.2 Compression 

The gas compression plant houses the following five (5) compressors:

Compressor Operating Status

Acid Gas A Nonoperational

Acid Gas B Operational

Aerial C-5 Operational

HOS-4 Operational

HOS-6 Operational

Acid Gas B, Aerial C-5, HOS-4, and HOS-6 are high-speed electrically-driven reciprocating compressors. 

Aerial C-5, HOS-4, and HOS-6 are the primary facility compressors. 

Acid Gas A is a smaller unit and is only used for backup and excess throughput. Acid Gas A is non-functioning 

and uneconomical to return to service. It remains at the plant as a source of spare parts for the Acid Gas B 

compressor.

The compressors provide approximately 8,000 combined brake horsepower (BHP) and each compressor 

consists of four or five compression stages which raise the pressure of the incoming gas from 40 psig to 2,900 
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psig. Each stage has a dedicated aerial cooler and liquid scrubber vessel. Inter stage dehydration takes place to 

remove water for corrosion mitigation on the HOS 6 compressor. 

Isolation and operating procedures for the Acid Gas B, Ariel C-5, HOS 4, and HOS 6 compressors are included 

in the appendix to this report.

1.3 Re-Injection 

The compressor units discharge into a single header, where purchased carbon dioxide (CO2) is co-mingled to 

achieve a daily injection rate of up to 24 MMSCFD. The gas is then distributed to the field. 

During gas compression plant upsets or compressor downtime events, a portion or all of the inlet volume to the 

gas compression plant is automatically diverted to flare until the problem is corrected.

************************************ 

Shaheerah Kelly

Permits Office, Air Division (AIR-3)

U.S. Environmental Protection Agency, Region 9 

San Francisco, CA 94105 

Phone: 415-947-4156 

Fax: 415-947-3579 

Email: kelly.shaheerah@epa.gov

  

  

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