Source: Equinor official website

Carbon Dioxide Storage: A Beacon of Hope for Climate Change and a Key Path to a Low-Carbon Future

Carbon dioxide storage (a core technology of CCS/CCUS) is being regarded by the global energy industry as an important solution to address climate change. It enables oil giants to continue providing stable energy to the world while reducing carbon emissions, seemingly building a pragmatic bridge for the transition from high-carbon to low-carbon energy. Over the past few decades, billions of US dollars have been invested globally to promote the development of CCS, and several projects have successfully achieved CO₂ capture and permanent storage, injecting strong momentum into the achievement of carbon neutrality goals. This technology is not only a key path to addressing climate challenges but also an innovative force driving the green transition of the energy industry.

Deep Saline Aquifers: Injecting CO₂ into underground saline aquifer spaces, which is currently the most potential method.

Depleted Oil and Gas Reservoirs: Injecting CO₂ into depleted oil and gas fields.

Enhanced Oil Recovery (EOR): Driving out crude oil while injecting CO₂, achieving a win-win situation of economic benefits and environmental protection.

Deep Unmineable Coal Seams: Adsorbing CO₂ on the surface of coal seams.

Through chemical reactions, CO₂ combines with magnesium- and calcium-containing silicate minerals (such as olivine and serpentine) to form stable solid carbonate rocks (such as marble-like substances). Theoretically, this method is the safest because it is permanent solid storage.

Dissolution Type: Injecting CO₂ into deep oceans (below 3,000 meters) to dissolve it in seawater.

Lake Type: Forming “CO₂ lakes” on the deep seabed. (Note: This method is highly controversial and not mainstream due to potential risks to marine ecology.)

Biomass Carbon Sink: Fixing carbon in plants and soil through photosynthesis by means of afforestation, wetland protection, etc.

Industrial Utilization: Converting CO₂ into chemical raw materials, plastics, building materials, or synthetic fuels.

Currently, the most mainstream, technologically mature form with large-scale commercial application potential is geological storage.

Among geological storage, the following two paths are the most common:

Enhanced Oil Recovery (EOR): It is currently the most commercialized. Oil companies inject carbon dioxide into oil reservoirs to dilute crude oil and increase pressure, thereby driving out residual oil that cannot be extracted from the ground. This method can generate economic benefits to offset part of the capture costs, so it is the most widely used.

Deep Saline Aquifer Storage: It has the largest potential and storage capacity at present. It uses deep underground (usually below 800 meters) non-potable saline aquifers to store carbon dioxide. Although it cannot be directly converted into oil like EOR, it is the core technical path to achieve large-scale carbon neutrality due to the wide distribution of such geological structures.

A recognized pioneer in the industry. It is currently cooperating with Shell and TotalEnergies to advance the Northern Lights transnational carbon storage project, a landmark in Europe.

Aker Solutions has won the EPC (Engineering, Procurement, Construction) contract for onshore receiving terminal facilities and subsea injection systems. They are responsible for the overall system integration from onshore terminals to subsea injection devices.

Phase 1 Project

Progress Status: Construction was completed in 2024, and commercial operation is expected to start in the third quarter of 2025.

Aker Solutions is responsible for the engineering and construction of the onshore receiving terminal, Subsea7 undertakes the laying and installation of the 100-kilometer subsea pipeline, and OneSubsea is responsible for the development of the subsea injection system. The steel pipes for the 100km main line of Phase 1 are supplied by Germany’s EUROPIPE (using X65 grade carbon steel), welded and prefabricated by Subsea7 at its base in Vigra, Norway, and laid on the seabed using professional vessels. It has a carbon storage capacity of 1.5 million tons per year (1.5 Mt/y). Construction contents include a dedicated CO₂ loading and unloading terminal, a 100-kilometer subsea pipeline, and 2 injection wells.

Phase 2 Project

Launched in the second quarter of 2025, it is planned to be put into production in 2028. Aker Solutions will continue to be responsible for the expansion of onshore facilities, Subsea7 for the procurement and installation of new pipelines, and SLB OneSubsea for the subsea injection system.

Phase 2 Branch Line (5km): Also undertaken by Subsea7 for EPCI (Engineering, Procurement, Construction, and Installation), connecting new injection devices. It adopts high-strength carbon steel meeting DNV 450 FPDS (corresponding to API 5L X65) standards, and the inner wall of the pipeline is coated with high-performance liquid epoxy resin to cope with the characteristics of supercritical CO₂. Key constructions include 9 new large-scale CO₂ storage tanks, expansion of terminal facilities, and 2 additional injection wells. The storage capacity will be greatly increased to more than 5 million tons per year (5 Mt/y).

Phase 2 has introduced self-healing/quantum monitoring technology, which senses millisecond-level pressure fluctuations through optical fibers to prevent long-range brittle fracture.

HEM-AFT Model (Full Name: Homogeneous Equilibrium Model – Augmented Fracture Tool): “High-Fidelity Physics-Based Supercritical CO₂ Pipeline Crack Arrest Monitoring and Risk Assessment Technology”.

Developed jointly by University College London (UCL) and SINTEF (Norwegian Institute of Industrial Research), the core of this “self-healing” monitoring system lies in solving the unique “crack arrest” problem of supercritical CO₂ pipelines through ultra-fast physical modeling.

Supercritical CO₂ pipelines face a more dangerous problem than natural gas pipelines: when a small crack in the pipeline causes pressure relief, CO2 will expand violently and cool down rapidly (dropping below -78°C), leading to brittle transition of the steel. This embrittlement will cause cracks to propagate along the pipeline at an extremely fast speed, forming a “zipper-like” burst hundreds of meters or even kilometers long.

Operation Mechanism of the Monitoring System

This system is called “self-healing” monitoring, which does not mean that the metal material grows automatically, but achieves a safe closed loop through “predictive control – real-time intervention”:

1. Distributed Fiber Optic Sensing (DFOS): Optical fibers are attached along the entire outer wall of the pipeline. Using the principle of Brillouin scattering, the optical fibers can sense tiny strain changes and temperature fluctuations up to 0.01°C.

2. One-Millionth of a Second Detection: Sound waves and sudden temperature changes generated by pressure relief are transmitted back through optical fibers. The digital twin model compares them in real time in the background. If the system judges that the fluctuation has “fracture-induced characteristics”, it will send a signal before the crack penetrates the pipe wall.

3. Automatic Control Valve (“Self-Healing” Behavior): The system will instantly trigger the intelligent actuators on both sides of the affected pipe section, and offset the local cooling pressure by adjusting the pressure wave to prevent crack propagation.

In 2026, the application of Northern Lights Phase 2 covers a 110-kilometer subsea pipeline from the onshore receiving terminal to the deep-sea injection well. Traditionally, to prevent long-range fracture, it is necessary to thicken the pipe wall or add expensive “crack arresters”. This monitoring system allows the use of relatively thin X65 grade steel, reducing the pipe material cost by about 15%. In the simulation test of the Phase 2 project, the system’s recognition accuracy for potential leakage points has been improved to 99%, and the early warning response time has been shortened to less than 150 milliseconds.

It has one of the world’s largest capture and storage capacities. The ongoing Rose Carbon Capture and Storage (CCS) project is a key permanent geological sequestration hub project developed by ExxonMobil Low Carbon Solutions in Jefferson County, Texas, providing CO₂ transportation and underground permanent storage services.

Project Location and Geological Conditions: The storage site is located on more than 13,000 acres of private land. CO₂ is injected 0.5–1.5 miles (approximately 2,640–7,920 feet) below the surface, and the injection layers are mainly the Upper Frio Sands and Fleming Sands geological formations.

Infrastructure: 18-mile (approximately 29-kilometer) new CO₂ pipeline: connecting the Mid-County capture source to the storage site in western Jefferson County (TX-245 Rose CCS Pipeline, operated by ExxonMobil Low Carbon Logistics). The pipeline is designed for high-pressure dense-phase CO₂ transportation.

Progress and Regulatory Status (as of April 2026): June 2024: Drilling activities started.

October 2025: The U.S. EPA officially issued 3 Class VI UIC (Underground Injection Control) permits, allowing the conversion of test wells into permanent storage injection wells. This is a key milestone for the project, supporting long-term geological sequestration.

2025–2026: Applying to the Texas Railroad Commission (RRC) for state-level Class VI permits (or state permits under primacy). The project has entered the prehearing and hearing stages (a hearing was held in March 2026), with local residents expressing concerns about safety and environmental impacts (including groundwater, earthquakes, and leakage risks). Some hearings involved protests, but the project is still progressing.

A highly representative transitioning owner. Through its subsidiary 1PointFive, it is building Stratos, the world’s largest Direct Air Capture (DAC) plant, in the Permian Basin, planning to permanently store the captured carbon dioxide underground or use it for enhanced oil recovery.

The Stratos project, located in the Permian Basin of Texas, USA, is currently the world’s largest under-construction Direct Air Capture (DAC) plant. The following is detailed contracting, construction, and infrastructure information of the project:

The project adopts an innovative modular construction model to significantly shorten the construction period.

Worley has provided comprehensive support from Front-End Engineering Design (FEED) to the current construction phase. They jointly developed a modular assembly line called “DACtory” with 1PointFive, which assembles capture units on the ground and hoists them as a whole, reducing the construction period from the expected 29 months to 15 months.

The location of Stratos is highly strategic, directly utilizing the mature oil and gas infrastructure in the Permian Basin. It mainly uses the existing CO2 pipeline system of Occidental Petroleum (Oxy). Occidental Petroleum operates the world’s largest CO2 pipeline system (with a total length of more than 2,500 miles) in the Permian Basin for its traditional Enhanced Oil Recovery (EOR) business.

It adopts high-density steel pipes meeting API 5L standards (usually X65 or X70 grade), specially designed for transporting supercritical or liquid carbon dioxide. To cope with acid corrosion caused by the combination of CO2 and trace water, the inner wall of the pipeline usually needs special epoxy resin coating treatment, and is equipped with strict drying and pressure monitoring systems.

Storage Path: The captured CO2 is transported through pipelines to deep saline aquifers (brine layers) more than 2,600 meters underground for permanent geological storage. The project has obtained a Class VI injection permit issued by the U.S. Environmental Protection Agency (EPA).

Latest Progress: As of the beginning of 2026, the project has entered the commissioning phase and is expected to officially start commercial operation in 2026.

It operates one of the world’s largest CCS projects in Australia — Gorgon, which injects carbon dioxide associated with the extraction process into deep underground saline aquifers. Gorgon CCS Project

Owners (Party A): Chevron (operator, holding 47.3%), ExxonMobil (25%), Shell (25%), and three Japanese energy companies.

Kellogg Joint Venture Group (KJVG), a consortium composed of four companies: KBR (Kellogg), JGC (JGC Corporation), Hatch, and Clough. They are responsible for the design and construction management of the entire Gorgon Liquefied Natural Gas Plant and its associated CCS facilities.

The pipeline design of the Gorgon project is extremely demanding because CO2 needs to be transported from the onshore plant to the injection platform under extremely high pressure. EUROPIPE (a German company) provided key high-strength large-diameter steel pipes. Saipem is responsible for the installation of subsea pipelines and related infrastructure. The pipeline material adopts API 5L X65 or equivalent grade high-strength carbon steel. Since CO2 may precipitate water under pressure changes leading to acid corrosion, the inner wall of the pipeline adopts high-performance liquid epoxy resin inner coating. In the injection port area directly in contact with the saline aquifer, Super Duplex Stainless Steel is used to resist the double erosion of extremely high salinity and acidic environment.

No matter how CCS evolves in the future, one thing is certain: any project involving large-scale transportation and injection of supercritical CO₂ requires the highest standards of pipeline safety and long-term risk control.

GM Piping is at the forefront of this low-carbon transition — we do not sell concepts, but only focus on providing the highest standard flanges, pipe fittings, valves, and pipeline systems. With the help of the powerful intelligent AI model BANGUO, combined with the HEM-AFT model to be integrated in the future (high-fidelity physics-based supercritical CO₂ pipeline crack arrest monitoring and risk assessment technology), we help global projects achieve upgrades from material selection to full-life-cycle intelligent health management.

On the path of the continuous development of carbon storage technology, let every ton of CO₂ be transported through a safe, intelligent, and reliable pipeline system — this is the most pragmatic contribution that GM Piping can make to the earth’s low-carbon future.