About CCUS

Projects

Carbon capture, transport, and storage is a proven process that can create a new Louisiana industry, sustain existing jobs and benefit local communities.

Overview

Louisiana has the right recipe for safe carbon storage. Its geology is like a giant underground layer cake built over millions of years. Rivers left behind sands and gravel, and then seas added layers of shale and rock, over and over as sea levels rose and fell. The resulting layers of porous sandstone act like a sponge for storage, sealed in by the solid rock layers, hundreds of feet thick. This layer cake of sand and rock has securely held oil and natural gas for millions of years and can just as safely store captured CO2 emissions.

After decades of drilling in Louisiana, ExxonMobil has detailed knowledge of Louisiana's subsurface. We use that expertise to find prime locations for safe and effective storage, secure permits, construct the storage wells and eventually store CO2.

Subsurface Geology

Allen Parish

Iberville Parish

St. Landry Parish

Benefits

  • Sustains Louisiana jobs by enabling manufacturers to lower their carbon emissions to satisfy environmental regulations and successfully compete in the global marketplace
  • Provides millions of state and local tax revenues
  • Creates well-paying construction jobs
  • Creates another beneficial use for/provides greater economic value to land above the storage site and along the pipeline route
  • Encourages economic development locally and across the state
  • Reduces the carbon-intensity of many products and activities that Louisianians enjoy, thus allowing them to continue enjoying them at affordable prices into the future
  • Reduces the amount of CO2 that would have entered the atmosphere

A Heavily Regulated Process

Permit Process video
  • Primacy: The EPA granted Louisiana the authority to regulate CO2 storage because the Louisiana Department of Conservation and Energy (LDCE) has deep knowledge of Louisiana’s geology, decades of experience with underground wells, and a regulatory regime that meets or exceeds federal standards.
  • Class VI Permit: Storing CO2 underground requires a Class VI (Class Six) permit to construct and operate each CO2 storage well. The permit process is designed to ensure the CO2 will stay safely and permanently underground and will not affect U.S. Drinking Water (USDW), which are sources of water that even if undrinkable today, could be treated to become drinkable in the future.
  • Research Well Permit: To receive a Class VI permit, operators must provide extensive evidence to prove that storing CO2 in a particular site would be safe. To collect this evidence, operators may need to drill a research well to conduct the underground studies. Doing so requires a permit.
  • Long, Detailed Process: From start to finish, the process of identifying locations, studying the geology, collecting and analyzing data, and eventually reviewing the data with regulators can take about two years or more. Because data from the research well process contributes to the Class VI application, companies may apply for both permits at the same time. If the research well returns poor results, the Class VI application can be withdrawn.

*Site research required by Class VI permits can be completed without using Class V research wells. If they are used, the Class V and Class VI permit processes can happen at the same time.

Initial Study: Locating a Safe and Secure Storage Site

At ExxonMobil, safety guides our search for storage locations. Before we even express interest in storing CO2 in a certain location, we conduct extensive research to find areas of the underground “layer cake” that are most likely to support safe and secure CO2 storage.

Before Applying for Permits

  • Narrowing Down Locations: We use our extensive geological data, developed during decades of exploration in Louisiana, to look for areas that are expected to have:
    • Large layers of pore space
    • Multiple layers of thick cap rock
    • No faults or fractures that would allow CO2 to escape
  • Determining Feasibility: Once a promising area is identified, we then consider a number of other feasibility factors. A critical one is whether landowners in the area would be willing to grant underground storage rights in exchange for fair, market-based compensation.

Research Well Permit Process

Once geology and land agreements align, ExxonMobil begins a detailed research process designed to determine whether the specific site can be proven to support safe, secure and environmentally responsible CO2 storage. Based on the results, we decide whether to continue pursuing the project or turn to other options.

Permit Process video

This effort often involves drilling a research well to:

  • Collect rock samples to study the quality of the rock formations
  • Inject brine, salty water similar to what already exists underground, into the proposed storage area to test how the brine moves within the pore space and whether the cap rock continues to contain the liquid.

Application for Research Well

LDCE requires a permit to drill this type of research well. As part of the permit process, ExxonMobil must provide information about our:

  • Location
  • Well design and construction details
  • Research plan

Research Well Phase

Installing the Research Well: If approved, we build the research well to essentially the same standards as those required for CO2 injection wells, even though the research well will not be used to store CO2. LDCE periodically inspects the construction of the well to ensure it is built according to regulations.

In-Depth Research: Once we start drilling, the real research begins.

  • Studying the geology: Collecting rock samples and data to identify the layers of pore space, where CO2 would go, and cap rock, the seal that would keep it in place.
  • Mapping water sources: Identifying the locations and depths of underground sources of drinking water (USDW) so they can be protected.
  • Evaluating reservoir behavior: Injecting fluids, typically brine similar to what already exists underground, to see how liquids move through the pore space.
  • Confirming sealing capacity: Examining whether the cap rock continues to prevent fluids from migrating out of the storage layer.
  • Gathering data for Class VI permit: Producing the initial technical data required for the permit application.

Some of ExxonMobil’s top subsurface experts spend several months carefully analyzing the data in preparation for a Class VI permit, which would undergo thorough regulatory review.

Class VI Process

The Class VI (Class Six) permit process is designed to ensure the CO2 will stay safely and permanently underground and will not affect U.S. Drinking Water (USDW), sources of water that even if undrinkable today, could be treated to become drinkable in the future.

Learn More

Class VI Permit video

The process incorporates the research well findings, if a research well was installed, and is designed to:

  • Determine the area of storage: Identify the boundaries of the area under which CO2 is expected to be stored; repair or plug any unsafe wells within the area.
  • Certify the geology: Demonstrate there are multiple layers of cap rock that are hundreds of feet thick, stretch beyond the storage area and do not allow CO2 to pass through them.
  • Confirm well design: Show how wells will be engineered with corrosive protection and multiple layers of steel and cement to prevent leaks of CO2 or other fluids.
  • Validate operational planning: Detail the proposed daily injection rates; the volume to be stored; how the movement of the CO2, reservoir pressure, and condition of the wells will be monitored; and how to respond to the unlikely event of an emergency.
  • Assure financial responsibility: Prove the operator can fund long-term responsibilities.

Operations Phase

Once LDCE confirms the operational plans and well construction meets regulatory requirements, it will grant the Class VI permit so operators can begin storing CO2.

Learn More

Operations / Storing CO2 Underground

 
  • Process: CO2 is pumped more than a mile down the well into the storage layer where it mixes with the brine that exists within the pores of the storage layer. This brine is so salty (oftentimes 3-4x saltier than water in the Gulf of America) it cannot be treated for human use.
  • Natural pressure: At about a mile deep, the brine moves through the pores of the storage layer because it is naturally under about 2,500 pounds per square inch (psi) of pressure.
  • Added pressure: Injecting CO2 only raises the reservoir pressure slightly — about 1-8 percent near the well and 1–3 percent further away across the storage zone.
  • Locked in: The cap rock, which is hundreds of feet thick, keeps both the brine and CO2 sealed underground because it is impermeable and typically can withstand nearly twice the pressure, about 4,500 psi of pressure.

Once underground, although some of the CO2 remains mobile, either settling lower in the pore space or floating up under the cap rock, a large portion of the CO2 will actually dissolve into the brine. Over time, some of this dissolved CO2 will react with the minerals in the rock and solidify.


Ongoing Regulatory Oversight

After startup, operators remain subject to long-term regulatory requirements. LDCE requires them to conduct:

  • Continuous monitoring and reporting
  • Mechanical integrity testing
  • Area of Review (AOR) evaluations and updates
  • Corrosion and materials integrity testing
  • Emergency response planning and training
  • Financial responsibility assurance tests

Post Operations Phase

After decades of storage activity, operations will eventually come to an end, but LDCE will continue its regulatory oversight for decades more. Operators must continue monitoring the CO₂ plume and pressures after injection ends. Only after LDCE determines the site is stable can the operator transfer long-term responsibility to the state.

Storage Safety

Hear From ExxonMobil Employees on CO₂ Underground video

CO2 storage sites are designed, constructed and operated in a way that protects people and the environment, especially sources of underground drinking water (USDW).

  • Geography: Operators conduct extensive research to prove the storage layer is geologically sound and covered by multiple layers of cap rock that are hundreds of feet thick, stretch well beyond the storage area, and are impermeable so CO2 cannot pass through them. These thick, natural formations have securely held oil and natural gas for millions of years and can just as safely store captured CO2 emissions.
  • Well design: Wells are built to encase the CO2 with three layers of corrosion-resistant steel and two layers of fortified cement. They also have shutdown valves at the top and a specially designed plug at the bottom to prevent any fluids from traveling back up.
  • Operational planning: Operators conduct detailed research to determine safe injection rates and pressures that set plans in motion to maintain them.
  • Monitoring and testing: The movement of the CO2, reservoir pressure and condition of the wells are tracked by state-of-the art technologies.
  • Emergency response planning and training: Although operators work to maintain safe operations, they plan and train how to respond to the unlikely event of an emergency, quickly and effectively.

Pipeline Safety

Hear From ExxonMobil Employees on CCUS Pipeline Safety video
“Statistics on the transportation of CO₂ in its supercritical form has been safer relative to other hazardous liquids/gases; releases have been rare, and releases have rarely impacted people or the environment.” Pipeline and Hazardous Materials Safety Administration (PHMSA)

CO2 pipelines have been operating safely for more than 50 years in the U.S.– and for more than 15 years in Louisiana.

  • Pipelines transporting CO2 in a near-liquid state are covered by hundreds of federal safety requirements.
  • ~ 5,200 miles of CO2 pipelines safely transport ~68 million tons of CO2 per year in the U.S.
  • Publicly available government pipeline safety data show CO2 pipeline incidents are rare and declining.
  • From 2001 to 2024, PHMSA recorded an average of less than five reportable incidents per year, no fatalities and one injury – a contractor hurt during an excavation of a CO2 pipeline.
  • CO2 pipelines have a lower incident rate than other hazardous pipelines. From 2001 to 2024, the average CO2 pipeline incident rate was approximately 0.001 incidents per pipeline mile.
  • Across the entire industry there were three incidents in 2022, four in 2023, and one in 2024. All with no injuries.
  • CO2 releases typically result in relatively minor, on-site impacts. On average, CO2 incidents result in damages valued 10 times less than the cost of incidents caused by other hazardous liquids pipelines.

Our Commitment to Landowners

Landowners play a key role in our CO2 storage projects. That is why ExxonMobil works to build long-term, respectful relationships based on transparency and trust.

Learn more

Landowner experience video

Frequently Asked Questions

What is carbon dioxide (CO2)?

CO2 is a colorless, odorless and non-flammable gas. It is everywhere. Humans exhale it. Plants live on it. It gives soft drinks their fizz. In addition to its being a naturally occurring gas, CO2 is also created from certain chemical reactions, including when we burn oil or natural gas to manufacture products or generate electricity. It is safe at normal concentrations. At very high concentrations, it can reduce oxygen levels, which is why operators install safeguards to keep concentrations at safe levels.

What is carbon capture and storage (CCS)?

CCS is the process of capturing CO2 from manufacturing facilities before it is released to the atmosphere, transporting it by pipeline to areas certified for safe and permanent storage and placing it about a mile deep, under the same type of impermeable layers of rock that have kept oil and natural gas underground for millions of years.

Why capture and store CO2?

CO2 plays an important role in the atmosphere. It helps trap the sun's heat, warming our planet and protecting it from the frigid temperatures of outer space. However, too much CO2 in the atmosphere traps too much heat and risks raising the earth's temperature. Many things we use produce CO2, including cars, planes, agricultural equipment and the manufacturing of countless daily essentials and building materials such as steel and concrete. As the world works to limit the level of CO2 in the atmosphere, we will either need to limit these activities or reduce the amount of CO2 these activities produce. If we capture the CO2 at the manufacturing site before it is released to the atmosphere, we can continue to benefit from activities and products that produce CO2, while meeting new limits on CO2.

What are the benefits of CCS?

CCS projects generate new investment dollars, sustain existing jobs in Louisiana’s critical industries, create new well-paying construction jobs, provide millions of dollars of compensation to landowners, and generate millions of dollars in state and local tax revenues. CCS also encourages economic development locally and across the state and reduces the carbon-intensity of many products and activities that Louisianians enjoy, thus allowing their enjoyment at affordable prices into the future.

How will the CO2 be kept securely underground?

Potential CO2 storage sites are carefully selected only after undergoing rigorous analysis to ensure they are suitable. Once stored, the CO2 is held in place by multiple layers of impermeable seal rock, hundreds of feet thick. These are the same types of cap rock that have kept oil and natural gas safely in place for millions of years. Over time, stored CO2 will either mineralize, dissolve or be otherwise securely trapped.

Will it affect groundwater or drinking water?

Underground sources of drinking water, defined by the EPA as sources of water that even if too dirty to be drinkable could be treated to become drinkable, will be protected by both the design of the well and the geology. The pipe used to place the CO2 underground is made of corrosion-resistant steel and is surrounded by two other steel pipes, both of which are encased in specialty cement formulated to withstand long-term exposure to CO2 and brine. The CO2 is placed in a porous storage layer thousands of feet below the sources of drinking water and underneath multiple layers of impermeable cap rock. We will continuously monitor the source of underground drinking water and rock layers in between to confirm CO2 has not left the storage layer.

What is a research well?

A research well, permitted by the Louisiana Department of Conservation and Energy, is used to better understand underground geology and determine if the underground rocks in the area are suitable for safely and permanently storing CO2 and can meet stringent environmental and safety standards. The research well findings are used to prepare an application for a Class VI permit that is required to install and operate a CO2 storage well.

Resources

Louisiana Land Commitment
Louisiana CCS Benefits
CO2 Pipeline Safety
CO2 Pipeline Regulation
ExxonMobil Low Carbon Solutions
CO2 Underground Storage Safety

See All Links

Parishes

Project details may vary by parish. For the most accurate and up-to-date information relevant to your community, please use the links below to access parish-specific pages.

Allen Parish


Iberville Parish


St. Landry Parish


Breaking Down the Process

Capturing, transporting and safely storing carbon dioxide (CO2) emissions is a proven process that will create a new Louisiana industry and help sustain jobs in the state’s industries that produce CO2. Learn more about each element of the CCS process.

Capture


Transportation


Storage


If you have any questions or feedback, please contact our team directly using the link below or by calling us at 888-804-4788.

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