The world is holding its breath, wondering: Is our ocean-stored carbon dioxide secure? As Norway and other nations embark on the ambitious mission of storing CO2 in undersea reservoirs, a team of researchers from the Norwegian University of Science and Technology (NTNU) is tackling the critical questions that arise. But here's where it gets controversial—how do we ensure this stored CO2 isn't leaking into the ocean? And how can we monitor it effectively?
Martin Landrø, an NTNU geophysicist and director of the Centre for Geophysical Forecasting (CGF), emphasizes the fundamental concerns: "Where has my CO2 gone? Is it leaking or not?" These questions are at the heart of the matter.
Norway, home to the world's longest-running undersea CO2 storage project at the Sleipner gas field, has injected a staggering 20 million tons of CO2 into a saline aquifer called the Utsira Formation. This is where the CGF researchers step in, employing a powerful data-analysis technique called full-waveform inversion to scrutinize the site's data.
A groundbreaking paper by CGF PhD Ricardo Jose Martinez Guzman reveals the technique's potential in confirming the presence and quantity of CO2. Philip Ringrose, a professor at CGF, explains, "We've gone from foggy glasses to a crystal-clear view, allowing us to visualize and comprehend the intricate layers and feeders." This advancement is a game-changer in CO2 storage monitoring.
Currently, companies use ships to tow acoustic sensors over these underwater formations, a time-consuming and costly process. But is there a better way? In land-based CO2 storage, drilling wells is an option, but not feasible for deep-sea sites like Norway's.
Ringrose highlights their unique approach: "We're pushing the boundaries of geophysics to prove its effectiveness." To achieve this, the CGF has constructed a new laboratory featuring a 2-by-4-meter water tank with a mockup of the Utsira Formation's top layer, simulating the cap rock that prevents CO2 leakage.
The lab's beauty lies in its ability to challenge the system. Kasper Hunnestad, a CGF postdoc, explains, "We can manipulate the data and see how it affects our understanding of CO2 distribution." This innovative approach could reduce monitoring costs and enhance accuracy.
CGF's industrial partners eagerly await the lab's results, recognizing the potential business opportunities. Centre director Landrø suggests an intriguing solution: using fiber optic cables instead of conventional seismic cables for monitoring. This technology has already proven successful in tracking whales, so why not CO2?
As the CGF continues its research, the world watches with anticipation. Will their efforts revolutionize CO2 storage monitoring? And what other innovative solutions might emerge? The answers could shape the future of carbon storage and our planet's health.
