Cost efficient, low carbon alternatives for cementing wells | SLB

Cost efficient low carbon alternatives for cementing wells

Published: 01/25/2024

EcoShield geopolymer cement-free system.

Cement is one of the most abundantly produced materials in the world and a substantial source of carbon emissions across the globe. Reducing carbon emissions from cement is a priority in the oil and gas exploration and production sector because cement is used in nearly every well drilled today.

SLB’s Sustainability Manager Sarah Moradi and Global Product Champion for Cementing Saurabh Kapoor discuss why low-carbon and cement-free systems matter for the industry and our planet. They also explain what SLB is doing as a technology company to offer both a technically sound and environmentally friendly alternative to traditional cementing solutions.

Q: Why are decarbonization and sustainability significant in well construction? 

Sarah Moradi: Decarbonization and sustainability in well construction are essential for minimizing environmental impact, complying with regulations, meeting social expectations and fostering innovation.

Many regions around the world have implemented regulations related to environmental protection and carbon emissions. Moreover, stakeholders, including investors and the public, are increasingly concerned about sustainability.

Q: The cementing process is one of the biggest contributors when it comes to the global carbon footprint. How is SLB working to address this?

Saurabh Kapoor: Cement is one of the biggest contributors of emissions due to its energy intensive manufacturing process, which accounts for slightly more than 5% of the global CO2 emissions.

Reducing carbon emissions from cement is a priority in the oil and gas exploration and production (E&P) sector because cement is used in nearly every well drilled today, with an impact of about one ton of carbon emissions per ton of cement used.

It is essential to ensure that future infrastructure is low carbon and does not lock in emissions for extended periods. More than 5 million metric tons of COequivalent global emissions a year could be avoided during the well construction process by using a sustainable alternative.

Our technology solutions do just that: Offer a more sustainable alternative for producers. For example, our CemFIT Heal flexible self-healing cement system provides a competent annular seal, delivers superior mechanical properties and auto-repairs during the life of the well. This assures longterm well integrity, reducing both direct and indirect COemissions.

Q: What other innovative technologies and solutions are emerging to address challenges we face with cementing? Are they as reliable and effective as conventional Portland cement?

SK: Cement-making requires carbon-intense heating. To make Portland cement, the most common type of cement used globally, limestone and clay need to be heated together in a kiln to about 2,500 degrees Fahrenheit.

But a bigger problem with making cement is what’s known as process emissions. Because limestone contains a lot of carbon, the process of heating it results in a chemical reaction that releases carbon dioxide.

Over the last several years, SLB took on the challenge of developing a well cementing system without cement. Last year, EcoShield™ we launched the geopolymer cement-free system that minimizes the CO2 footprint of a well’s construction.

In addition to its embodied COemissions, Portland cement creates significant transportation-related emissions from manufacture to deployment. The EcoShield system uses locally sourced natural materials and industrial waste streams in its composition, making this a far more sustainable well integrity method.

As a low carbon alternative, the system eliminates up to 85% of embodied CO2 emissions compared with conventional cement systems, thus enabling the benefits of a circular economy.

Q: Speaking of the Portland cement system, conventional cement systems used in carbon storage wells can be detrimental to well integrity because they can degrade rapidly upon exposure to CO2. How are you addressing this issue to make underground carbon storage a reality?

SK: Loss of well integrity could be one of the main risks contributing to leakage of CO2 from underground carbon capture and storage sites. Globally, various industries are evaluating the potential to store carbon underground.

We’ve developed a technology to address this. Our EverCRETE CO2 resistant cement system not only maintains integrity under exposure to the most critical CO2 conditions, but it also has a self-healing ability to repair cracks and micro annuli on contact with CO2.

Q: Tells us about EverCRETE and EcoShield technologies – how do they work and have they been used successfully?

SK:The EverCRETE system enables efficient underground storage to keep greenhouse gasses out of the atmosphere. The technology has been successfully placed in multiple carbon capture and sequestration projects globally

With the EcoShield system, performance can match or even top the technical performance of conventional cement systems. The cement-free system can be deployed throughout various phases of the well life cycle, including abandonment. It can also be deployed across a range of field applications, including corrosive environments.

SLB has successfully deployed the EcoShield system in over 100 wells and counting. These trials validated the ability of the technology to fit within standard oilfield cementing workflows without major changes to the design process, onsite execution, or post-job evaluation while substantially reducing the CO2 footprint in the well construction process.

Q: What needs to change for industry to accept solutions like EcoShield or EverCRETE?

SM: Investment in the development of chemistries to fit oil and gas applications needs to increase. And there needs to be a regulatory willingness to change and adapt to new sustainable alternatives There also needs to be a mindset change to adopt new offerings.

We are working to help accelerate the industry’s path to net zero and that includes reducing carbon emissions from cement. Our CemFIT Heal, EcoShield and EverCRETE systems are examples of cementing technologies that are driving high performance, sustainably.

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