Reducing Hydrocarbon Emissions in Gas Lift Operations

ertWill Nelle, the Director of Technology and Innovation at Estis, delivered this exciting presentation on emissions reduction technologies in gas lift at the Southwestern Petroleum Short Course in April of 2024.  Below is a video recording of the full presentation, a brief synopsis, as well as a link to the slide deck. Enjoy!

Reducing Hydrocarbon Emissions in gas lift operations


Will Nelle, Estis Compression


Hey everyone! Will Nelle here, Director of Technology and Innovation at Estis. Thanks for joining me today. I promise this will be more interesting than you might think, even if you're not a compressor nerd like me. Let's talk about compressors and gas lift operations. Before you roll your eyes and leave, hear me out. This isn't a bait and switch, and I promise you'll find something useful here.

So, a little about me—I’ve been in the compressor industry for 22 years. I get that compressors might not be everyone’s cup of tea. For many, they’re just a necessary evil. But compressors are crucial to gas lift operations, which are becoming increasingly popular. That means you have to deal with compressors whether you like it or not.

The Annoying Side of Compressors

Now, let’s face it: the environmental regulations that come with compressors can be a real pain. Terms like EPA, NSPS, Quad OB, Quad OC, and Subpart W might make your eyes glaze over. If you've ever had to read those regulations, you know they can feel like a special kind of torture. But we can’t ignore them; they’re a reality. My goal today is to help you push those regulations to the side so you can focus on what you love: oil and gas production.

Seeing the Bigger Picture

Imagine looking at an oil and gas facility through an Optical Gas Imaging (OGI) camera. Even if you're not used to these images, you can easily spot gas emissions, or "plumes," from various points, especially from compressors. Compressors are a significant source of methane emissions in oil and gas facilities. It’s a big deal, and we can’t ignore it.

Understanding Methane Emissions

From studying emissions, it's clear that compressors contribute heavily to methane leaks. If you’ve done internal studies, your numbers might differ, but the bottom line is the same: methane emissions from compressors are significant. We need to tackle them head-on. The main sources of these emissions in compressors are blowdown, pneumatic actuators, compressor rod packing, and engine crankcase blow-by. Traditionally, blowdowns and pneumatic actuators are seen as the biggest offenders, but when you dig into the numbers, it turns out engine crankcase blow-by and compressor rod packing are actually worse.

Breaking Down the Leaks

Let’s break it down further. Engine crankcase blow-by happens when combustion gases escape past the piston rings into the engine crankcase, and then vent into the atmosphere. It’s a normal process for any engine, from natural gas engines on compressor packages to the car you drive.

On the compressor side, compressor rod packing tries to seal compressed gases inside the cylinder, but it’s not perfect, and some gas always leaks out. Again, this usually vents directly to the atmosphere.

Pneumatic actuators, which use gas pressure to move valves or louvers, leak in small, intermittent bursts. Though they contribute less overall, it’s still a leak we need to address.

Current Solutions and Their Drawbacks

So, what can we do about these leaks? For pneumatic actuators, we can use air compressors or electric actuators instead of gas. But these solutions are costly and might not be worth it for the small volume of gas they handle. For rod packing leaks, some vent to flares, others use vapor recovery compressors, but these methods also have their challenges and costs.

Engine crankcase emissions are often uncontrolled, simply venting to the atmosphere. This needs a better solution.

Enter CEVAC: A Game-Changer

This brings us to the CEVAC system (Compressor Emissions Evacuator), a patent-pending innovation from Estis. We developed CEVAC to handle these fugitive methane emissions efficiently. Here’s how it works: CEVAC collects emissions from various sources (like compressor rod packing and engine crankcase blow-by) and channels them into the engine intake system, burning them as fuel instead of venting them.

How It Works

We use an oil mist separator to ensure only gas enters the engine (no liquids). This system is scattered across the compressor package, but the key part is that it reroutes emissions to be burned in the engine, reducing methane emissions significantly.

Real-World Success

We installed our first commercial CEVAC system in early 2023 and now have about 50 in the field, with more on the way. Feedback from operators has been great—they’re not finding leaks during their LDAR surveys, which means CEVAC is working as intended.

EPA and Compliance

One big question is how the EPA views this system. While the EPA doesn’t certify systems, we had a third-party regulatory company review CEVAC. They confirmed it meets various federal emissions regulations, allowing operators to comply without the hassle of frequent packing replacements and detailed volume measurements.

Performance Data

We also tested how CEVAC affects engine exhaust emissions. The results were promising: even with CEVAC running, emissions stayed well below federal limits. This means we’re not just shifting the problem to the exhaust—we’re genuinely reducing overall emissions.

Wrapping Up

To sum up, compressors are a major source of methane emissions in oil and gas production, and we can’t ignore that. Traditional mitigation methods aren’t cutting it, but CEVAC offers a way to eliminate these emissions, comply with regulations, and let you focus on your core work: oil and gas production.

Got questions? Feel free to ask. And if you’re curious about more details or want to see the system in action, come by our booth later. We're always happy to chat and share more about how CEVAC can make your life easier and your operations cleaner.