Mature fields

Guest Editorial: Brownfield Optimization—The Key To Unlocking Sustainable Oil and Gas?

While innovative solutions are being examined for decarbonization, there is one topic that is rarely emphasized as a key driver in the path toward a more-sustainable future—brownfield optimization.

Drone View Of an Oil Or Gas Drill Fracking Rig Pad As The Sun Rises In New Mexico
Source: Getty Images

The topic of sustainability within the oil and gas industry has dominated news agendas in recent years. As "Net Zero by 2050" goals loom closer, the sector is under greater pressure than ever to decarbonize operations and source oil and gas via more-sustainable methods.

With the energy transition continuing at pace, the growth of renewable energy has been exponential. Energy sources such as nuclear and wind are set to account for a greater portion of the energy mix. Renewables expenditure is also expected to double over the next 10 years to more than $1,300 billion per year, and grid expenditure is likely to exceed $1,000 billion per year in 2030.

However, oil and gas will undoubtedly play a crucial role in meeting global energy demand for the foreseeable future. A recent industry reporthighlighted that conventional hydrocarbons are set to comprise 49% of the energy mix in 2050, emphasizing the sustained requirement for traditional hydrocarbons.

It is no secret the oil and gas sector is a high producer of carbon emissions, and according to the International Energy Agency, global production, transportation, and processing of oil and gas emitted the equivalent of 5.1 billion tons of CO2 in 2022. That’s almost 15% of total energy-related greenhouse gas emissions. So, how do we as an industry continue to extract this much needed energy source in a more-sustainable manner?

Methods to curb this emission are already in practice, with operators utilizing new technology to reduce waste-gas production, return the gas to on-site product streams, and reinject methane into reservoirs. A notable example came from ExxonMobil in January of this year with the company announcing it had stopped routine flaring of natural gas from production in the top US shale basin, using compressors to push natural gas to a pipeline. It has also allocated $17 billion through 2027 to lower its greenhouse gas emissions globally.

Electrification is also a hot topic, with operators investigating methodologies for how to reduce emissions from offshore assets. bp, Equinor, and Ithaca Energy recently signed a memorandum of understanding to explore electrification options for their offshore production facilities in the West of Shetland area in the North Sea. Electrification solutions could include power from shore, potentially from onshore wind, or from offshore wind. Full electrification would require in the region of 200 MW of power. If successful, the fields would become the first oil and gas developments on the UK Continental Shelf to be powered by electricity delivering a fully renewable solution.

These latest industry moves are bold. They certainly show that much-needed action is now taking place and that industry is responding to social and environmental pressures to make changes.

Yet, while new and innovative solutions are being examined, there is one topic which is rarely emphasized as a key driver in the path toward a more-sustainable future—brownfield optimization.

Mature fields present exponential prospects for the oil and gas industry to support global energy demands with a reduced carbon footprint. So, why is this not dominating the news agenda?

Simply put, many operators are unaware of the opportunities they present.

Brownfields are defined as oil or gas accumulations that have matured to a production plateau or even progressed to a stage of declining production. The advancement of technology has allowed existing developments which would have traditionally been abandoned to be rejuvenated. While this ultimately enhances production, it also delivers significant sustainability benefits.

Many reservoirs are abandoned, not because the oil reserves are fully depleted, but because they are too difficult, and costly, to reach. Norway is leading the way in this sphere, with some of the some of the highest recovery rates in the world.

The Troll field is a particularly strong example. It was initially deemed uneconomical with a thin oil column, and the reservoir structure made it nearly impossible to produce oil with conventional vertical wells. However, Equinor realized the value of technology investment to boost extraction and has pioneered the use of innovative systems, most recently coupling multilaterals and expandable drilling liners to gain greater economic value.

In comparison, many of the basins in the US land market which have been plagued with production issues for over 40 years are now prolific producers with the development of horizontal fracturing techniques. Even with advances in extended recovery techniques, the current recovery rate is still less than 12%. When oil prices peaked around 2008, operators worked quickly to drill, but this haste resulted in damaged formations which now require significant remediation to ensure they remain economical.

Ten years ago, when oil prices were high and environmental impact was lower on the priority list, an operator would simply shut up shop and begin drilling in a new field. But times have changed, and new technology is creating opportunities that were unthinkable at the time.

However, the tide is starting to turn. A recent report from Rystad Energy highlighted that workover spend is projected to jump by nearly 20% in 2023 and total $58 billion, with operators aiming to extract additional resources for existing wells, opposed to drilling new ones.

Expandable tubulars have been one of the greatest game-changers for brownfield optimization. The progression of this technology allows operators to solve complex well-integrity issues such as reducing water production, sand ingress, or nonproducing perforations without losing valuable inner diameter (ID), keeping the production viability high. Furthermore, sidetrack drilling to allow for greater reservoir drainage with horizontal wells enables economic operations to take place, keeping the production conduit large.

Modern expandable technology uses high-performance materials and seals, enabling them to handle high treating pressures as well as the induced loads from large temperature cooldowns seen in the fracturing environment or deep wells. Many conventional straddles deployed during well-intervention operations restrict the ID of the well, which can negatively impact production rates and wellbore access and increase project costs. As operators attempt to gain greater recovery and extend the life of existing fields, it’s essential that an enhanced flow area is achieved. Expandable patches are ultimately restoring and relining existing wells, allowing operators to continue producing from a reserve which may have been previously deemed uneconomical.

By utilizing and essentially recycling existing infrastructure and surface equipment, the requirement for drilling drastically reduces, and therefore the recovery of oil becomes far more sustainable. Some of the latest expandables available on the market today don’t even require rigs, with wireline deployment a possibility, reducing a project’s carbon footprint even further.

There is substantial work to do in changing mindsets and educating operators in the opportunities available to them through expandable technology. Governments also play a crucial role in driving this initiative.

Hydrocarbons remain an essential element of the energy mix, so it is critical that incentives which support emission reductions in this sector are in place. There is no denying that the oil and gas sector still follows a ‘race-to-be-second approach,’ so by subsidizing technology development and funding pilot projects, substantial carbon reductions can be garnered in the extraction of oil and gas.

There have been promising moves, with the US Department of Energy announcing in February this year it was seeking applications for up to $74 million in funding for pilot projects that can help advance the commercialization of enhanced geothermal systems. It also revealed it would invest $131 million for 33 research and development (R&D) projects to advance the wide-scale deployment of carbon-management technologies to reduce CO2 pollution. This funding is already enabling greater R&D in much-needed technologies.

Expandables will be key in supporting CCS projects, allowing relining of the full wellbore ensuring well integrity from an aged well. Currently, most oil and gas casing materials are manufactured with high-grade carbon steel. For operations where high levels of CO2 are present, exotic steels are required. The industry is still largely unaware that this steel grade can already be applied in expandable casing—opening significant opportunities in the CCS sector and allowing existing oil and gas wells to be repurposed for CCS purposes. Progress is already evident with projects in the US, UK, Kuwait, and Australia.

As the decarbonization of oil and gas intensifies, greater collaboration is required between operators, supply chain, government, and industry bodies to ensure that we effectively harness the opportunities available to us. By combining shared knowledge with existing technologies, significant efficiencies can be garnered in brownfield operations, allowing the industry to strike the balance of meeting global energy demands while substantially reducing carbon footprint.