GHG Mitigation Efforts
Leak Detection and Repair (LDAR):
Our methane and air emission controls include a robust LDAR program. Any detected leaks found during periodic inspections are repaired promptly to minimize emissions. Our LDAR program meets or exceeds federal and state (WV and OH) requirements. The LDAR program inspections utilize a state-of-the-art Optical Gas Imaging (OGI) Forward Looking Infrared Radar (FLIR) camera to identify leaks. We employ four full-time technicians to conduct and record the results of the LDAR inspections. These technicians have successfully completed FLIR camera training and are certified OGI camera operators. Inspections are conducted jointly by LDAR inspectors and operations personnel. Any detected leaks are typically repaired during the inspection. If the repair cannot occur during the inspection, the issue is tracked in our maintenance ticketing software and is fixed as soon as practicable, but no later than 30 days unless there is justification for placement on our Delay of Repair (DOR) list. 100% of Antero’s permitted facilities undergo LDAR inspections.
Practices to Reduce Flaring/Gas Combustion:
Antero reduces the amount of gas that requires combustion by flares or similar devices by using multiple stages of separation along with vapor recovery units and vapor recovery towers. This engineering control minimizes the amount of waste gas that is generated at the tanks. The remaining waste gas generated is either captured by a vapor recovery system and sent into the pipeline, burned in an enclosed combustion devices (ECD) with a control efficiency of at least 98%, or a combination of both.
To minimize flaring emissions during completion activities, Antero utilizes balanced drill outs. This technique limits the amount of gas that reaches the surface during completions. Since the amount of gas that reaches the surface is very minimal, the amount of gas that is required to be flared is also very minimal. The minimal gas that does reach the surface is not of a saleable quality, so it is destructed by a flare with a control efficiency of at least 98%.
Additional GHG Mitigation Efforts:
In addition to the efforts outlined above, Antero has completed or initiated the following methane emissions reduction activities:
- We operate burner management systems with three stages of pressure control to optimize combustor efficiency on storage tanks and to minimize methane emissions.
- We use weighted thief hatches on all new tanks to reduce tank emissions.
- We utilize green completions/balanced drill outs for all well completions to reduce emissions.
- We test pressure relief valves on a routine basis and repair or replace valves as necessary, reducing the amount of incidentally released methane.
- We switched to air-actuated pneumatic controllers at most compressor stations to eliminate the methane emissions that occur with gas-operated controllers. We do not utilize high-bleed controllers at any of our midstream facilities.
- We completed the transition from intermittent bleed to low bleed pneumatics at all of our new production facilities to further reduce associated methane emissions.
- We replaced gas-operated compressor engine starters with air or electric starters at select compressor stations to eliminate the methane emissions that occur with gas-operated starters.
- During construction, we implemented the use of hot taps when making a connection to an active line to prevent the need for blowing down long segments of pipe.
- Optimized glycol recirculation rates are utilized with flash tank separators on glycol dehydration units.
- Facility LDAR inspections were conducted at twice the frequency required by regulations during 2018.
Antero has formed a GHG/Methane Reduction team that meets quarterly to review, analyze and determine if we can implement emerging methane detection and quantification technologies applicable to E&P and Midstream operations. The team is currently investigating the following methane reduction technologies and practices:
- Developing a plug and abandonment plan for certain older vertical wells that were acquired in conjunction with property acquisitions. Plugging and abandoning older, low producing wells should reduce methane emissions.
- Reviewing options to recover gas from Midstream pigging operations.
- The replacement of TEG dehydrators with desiccant dehydrators where feasible.
- Installing electric driven centrifugal pumps on dehydration units that allow for Antero to fine tune the circulation rates, which in turn reduces flash emissions.
- Injecting blowdown gas into fuel systems at new stations to eliminate associated venting emissions.
- Utilizing technologies to assist with pipeline pump downs prior to maintenance and pigging to reduce gas venting.
- Utilizing electric compression at our new compressor stations to minimize emissions caused by gas combustion where feasible.
- Evaluating switching to air-actuated pneumatic controllers at the remainder of our compressor stations and at new production facilities to eliminate the methane emissions that occur with gas-operated controllers.