The 3rd RPI for January-February 2016: Erling Fjær

Chief Scientist at SINTEF Petroleum Research in Trondheim, Norway
Adjunct Professor at the Norwegian University of Science and Technology (NTNU)

About the influencer 

Erling Fjær is a chief scientist at SINTEF Petroleum Research in Trondheim, Norway. He also holds a position as adjunct professor at the Norwegian University of Science and Technology. For the last 30 years, he has been working within the areas of rock mechanics and rock physics.

Erling was educated in theoretical physics, followed by a PhD in solid state physics and a couple of years as post doc within the same subject. In the mid 80'ies, as the Norwegian petroleum industry was rapidly expanding, Erling was recruited to work within petroleum related research by a friend and former fellow student, Rune Holt, who suddenly found himself in charge of a large research project where most of the team had left for more exciting opportunities. Since then, they have worked in the same team on topics related to rock mechanics and rock acoustics, resulting among other things in the textbook "Petroleum Related Rock Mechanics", written together with Per Horsrud, Arne Raaen and Rasmus Risnes, first published in 1992 and in a second edition in 2008.

A few weeks after the Chernobyl accident in 1986, Erling met Dr. Leon Thomsen in Moscow, at the 2nd International Workshop on Anisotropy. A couple of years later this connection resulted in an Amoco-funded project with the objective to study experimentally the impact of cracks on elastic waves – a major cause for seismic anisotropy. Among the outcomes of this project was a technique to manufacture synthetic rocks with controlled crack geometry, a necessary step in order to verify several theoretical models.

The relationship between elastic wave velocities and rock mechanical properties has been a central part of Erling's work within rock physics. One of the outcomes of this work is a model describing the relationship between static and dynamic moduli, which is the core element in a commercialized tool for determination of strength and stiffness from wireline logs. A method for estimation of dispersion in the range from seismic to ultrasonic frequencies is another outcome of this work.

Your pathway for success in becoming a well known name in the rock physics community

My education in physics gave me several mathematical tools and approaches to problem solving that has been very useful for me in my work within rock physics. This transition from one branch of science to another has worked well for me. 

I have also been lucky to work in an environment that has been demanding for results while at the same time has given me freedom to chase my own ideas, in a balance that has been suitable for me. And I was lucky to enter into this research area at a favourable time. The development of petroleum related research in Norway in the 80'ies was spurred by the policy of the Norwegian authorities at the time, who stated that oil companies bidding for blocks in the North Sea would improve their chances of being awarded if they also invested in research at Norwegian institutions. This gave us possibilities to compete for funding that we could use to build laboratories and develop competence. Equally important, it also brought us in contact with the technical experts of the oil companies, some of whom were world leading experts within their areas. The support and advice from these people, as well as my colleagues, has been absolutely essential for me. 

Being lucky is not only a question of being at the right place at the right time. It is also a question of being able and willing to enter a window of opportunity when it opens up for you – even when there is doubt about your ability to reach that goal. I love to take on challenging problems, and I hate to fail – but sometimes I do. And so it should be. If you never fail as a researcher, your ambitions are too low.

Challenges you see in moving rock physics to the next level

Rock physics is a complex area, with several exciting challenges. A few examples:

- Much of our knowledge in rock physics is based on laboratory tests at ultrasonic frequencies, which are orders of magnitude above the seismic and sonic frequencies of field data. Following the developments in experimental techniques that allow for low frequency measurements in the lab, an update of this knowledge is called for – in particular regarding partially saturated rocks.
- Attenuation is a source of information that has not yet been properly utilized. 
- Much of what has been seen as "noise" in the past will be utilized as valuable sources of information in the future. 
- There is still a need for better models that can connect seismic data to rock mechanical properties, in particular for other rock types than sandstone.

Note also that rock physics will play a central role in future exploration of other planets. That will certainly take rock physics to a new level, literally speaking.

Advice for early career scientists (rock physicists, geophysicists, etc.)

From my perspective, rock physics seems like a fascinating area for a young scientist, with many intriguing questions yet to be solved and more to be identified as the development proceeds. Thus, there will be no shortage of exciting problems for the next generations of scientist. The major challenge will be to convince industry and authorities about the benefits of investing in rock physics.

It is difficult to predict future demand for rock physicists, especially now as the climate changes seem to be more challenging than the supply of energy. However, there will always be a demand for clever scientists, so the best advice I can give is to do your best, go to conferences and publish your results, have fun and look out for new opportunities. I do not know which problems you will be working on at the end of your careers, but I am sure that many of you will be working on a different branch of science than today. That need not be a problem. On the contrary, taking your knowledge from rock physics into another branch of science may be good – for you, for the society and for the development of science.

Good luck!

We thank Erling for his continuous contributions to the rock physics community.