Simulating secure CO2 storage
The race is on to develop the most secure solution for storing CO2 in the earth's crust. A new method studies precisely how this greenhouse gas is bound inside rocks.
Article from The Research Council of Norway
But how secure against leakage is this practice, and what is the holding capacity of different kinds of rock?
The Norwegian company Numerical Rocks AS has been studying how carbon dioxide moves and becomes "locked inside" the microstructure of sandstone and other rock.
CO2 will be safely stored in suitable geological formations deep below the ground. (Illustration: Bellona/Prosjektlab)
Sealed in by capillary forces
Using computer simulations of two-phase flow (CO2 and water) incorporated directly into three-dimensional images of reservoir rock, researchers and petroleum operators can calculate how gases and fluids either move or get trapped by capillary forces in the tiny hollow spaces (called capillaries) within a porous rock.
The method itself is simple enough, but the data algorithms behind it are extremely complex and require high-performance computational power, explain Thomas Ramstad and Håkon Rueslåtten of Numerical Rocks.
Studying flow in reservoir rock
"We calculate reservoir parameters based on a slow, continuous flow of water and CO2 within the pore system of the rock - and we represent this on a digital, three-dimensional image of the rock," says Senior Research Scientist Ramstad.
The 3D simulation above shows the distribution and movement of CO2 in sandstone capillaries under stationary flow conditions. On the right, non-stationary flow conditions (which occur near an injection well) are simulated. (Illustration: Numerical Rocks AS )
"The result is an animated 3D simulation of fluids within the rock, which enhances researchers' physical understanding of how these substances behave."
Stationary flow refers to the snail-paced movement of substances, typically just 30 cm per day, which takes place far from the injection well. This flow is controlled by capillary pressure conditions. The CO2 trapped in a rock's pores by capillary force does not leak out, even if the impermeable rock types above it crack open.
Numerical Rocks is now studying flow under non-stationary conditions - in the immediate vicinity of the injection wells - where the pressure is variable and flow occurs much more quickly.
Useful for petroleum sector
Numerical Rocks is certain that the need for this kind of simulation service will grow.
"Demand will increase as CO2 storage becomes more common," asserts Håkon Rueslåtten. "There is no doubt this will become a core activity of many major petroleum players."
The research has received public funding under the Norwegian RD&D CCS programme (CLIMIT), which is administered by the state enterprise Gassnova and the Research Council of Norway.
China 'Fastest-Moving' on CO2 Capture, Global CCS Institute
China, which is developing more than half of the carbon-capture and storage projects announced within the last year, is quickly becoming a leader in deployment of systems to cut emissions from power plants, according to the Global CCS Institute.
Article from Bloomberg
Currently there are 75 carbon-capture and storage, or CCS, projects in development worldwide compared with 74 a year ago, Brad Page, chief executive officer of the institute, said today on a media call. Nine were newly identified, including five in China, and eight were canceled or put on hold, he said.
"China is the fastest-moving nation now on CCS," Page said. The country "has moved very rapidly from right down in the bottom of our league tables to now being number three in the world in terms of number of projects," he said. The U.S. andCanada have the most projects.
Chinese companies are beginning to participate in projects in other countries, and that is a trend that may continue, Page said. China Petrochemical Corp., Asia's biggest refiner that's known as Sinopec Group, last month won an engineering contract for Summit Power Group LLC's CCS project in Texas.
"That may well turn out to be just a sign of things to come," Page said. "It's a very important development."
The Global CCS Institute is based in Canberra, Australia.