Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel method for investigating pore geometry in rocks

18.06.2018

Based on persistent homology theory, researchers from Japan's Kyushu University presented a new parameter and a new method for evaluating the heterogeneity of porosity

Whether or not we realize it, mathematics permeates our lives in countless ways. Sometimes, the role of mathematics is difficult to grasp, but other times it's rock solid.


Figure: Left: This is a digitalized 3D natural rock, Center: Spheres cloud representing pore topological features, Right: Persistence diagram.

Credit: International Institute for Carbon-Neutral Energy Research (I2CNER) / Institute of Mathematics for Industry (IMI), Kyushu University

Although the mineral grains that form a rock are important, it is the pores--the empty spaces between those grains--that often carry vital resources such as oil, gas, and drinking water.

The geometry of pores can strongly affect the storage, flow, and extraction of those resources. Thus, improving understanding of pore geometry is of great interest to many researchers and industry professionals.

In a fusion of mathematics and earth science, researchers from the International Institute for Carbon-Neutral Energy Research (I2CNER) and the Institute of Mathematics for Industry (IMI) of Kyushu University have now developed an innovative method to characterize pore geometry, based on a concept called persistent homology theory, as reported in a study published in Water Resources Research.

An important difference between natural rocks and artificial media is that the physical characteristics of rock tend to be relatively heterogeneous. This state-of-the-art method is particularly useful for characterizing that heterogeneity in pores.

As study first author Fei Jiang explains, "In the proposed method, complex pore geometry is first transformed into sphere cloud data. Then, a persistence diagram is calculated from the point cloud. A new parameter, the distance index H as a metric, is derived from the persistence diagram, and is proposed to characterize the degree of rock heterogeneity."

A strong relationship was confirmed between heterogeneity and the distance index H. In addition, a new empirical equation using this metric H is proposed to predict the effective elastic modulus of rocks.

"To test the newly proposed method based on the geometry of real rocks, four types of rock with different pore structures, including two carbonates and two sandstones, were investigated," co-author Takeshi Tsuji explains. "Persistence diagram analysis was more effective for quantitatively estimating the heterogeneity of relatively homogeneous sandstone compared with the conventional method. This new method was also superior in terms of distinguishing the different rock types."

Additional advantages of this method of analysis are that the persistence diagram is relatively stable with small changes in pore space, and the distance index H can be calculated very efficiently. Information extracted from persistence diagram analysis can be used to directly predict physical properties (such as permeability and elasticity) based on the microstructures of rocks. Thus, persistence diagram analysis may prove to be an important new tool for understanding the heterogeneity of pores in different rock types.

###

The article, "Pore Geometry Characterization by Persistent Homology Theory" was published in Water Resources Research at DOI: 10.1029/2017WR021864.

Media Contact

Akiko Uematsu, Public Relations Group, WPI-I2CNER
wpisyogai@jimu.kyushu-u.ac.jp
81-928-026-935

http://i2cner.kyushu-u.ac.jp/en/ 

Akiko Uematsu, Public Relations Group, WPI-I2CNER | EurekAlert!
Further information:
http://dx.doi.org/10.1029/2017WR021864

More articles from Earth Sciences:

nachricht Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen

nachricht The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>