Energy, Resources and the Environment

Earth Sciences: ‘Rocks for Jocks’, or hard science?

ERE Matters May 29, 2015

According to some Republicans in the US, Earth Sciences cannot be regarded as one of the ‘pure sciences’, or hard science. Is Earth Sciences simply Rocks for Jocks, or do the earth sciences actually encompass some fundamental work here? Suggestions have been made that NASA should steer its focus away from Earth Sciences and more onto space exploration and research. If NASA complies, it would most likely mean that will be redirected from Earth Sciences to Planetary Sciences, leaving less budget to study our own planet. A final vote still needs to be made, but what should the outcome be?

“Earth sciences are a fundamental part of science. They constitute hard sciences that help us understand the world we live in and provide a basis for knowledge and understanding of natural hazards, weather forecasting, air quality, and water availability, among other concerns.”

– American Geophysical Union CEO Christine McEntee –

I wholeheartedly agree with Christine McEntee, without Earth Sciences we would definitely not be able to study and better understand some of the most challenging issues society is facing these days: climate change, earthquakes, and energy production, to name a few. Less money automatically will mean less research being done to know more about our own planet. Knowing more about Earth will also help us to understand those other far-away inhabitable planets we are after.

Read the whole article on Science Insider, as well as one of the replies at the AGU Blogoshere. How do you feel about Earth Sciences as a pure science? Do you agree? What research are you doing to help us forward in understanding the Earth (or other planets)? Let us know 🙂

Total Solar Eclipse from the Perspective of Space (by Maximilian Reuter, taken from ImagGeo)

Words on Wednesday: Flow-through experiments on water–rock interactions in a sandstone caused by CO2 injection at pressures and temperatures mimicking reservoir conditions

ERE Matters May 20, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

This week, we would like to share with you the latest manuscript of Farhana Huq, who was our guest-blogger on Monday! 🙂

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Huq, F., S.B. Haderlein, O.A. Cirpka, M. Nowak, P. Blum, P. Grathwohl, 2015. Flow-through experiments on water–rock interactions in a sandstone caused by CO2 injection at pressures and temperatures mimicking reservoir conditions. Applied Geochemistry, v58, 136–146.

Highlights:

Altmark sandstone showed CO₂-induced fluid–rock interactions under in-situ conditions.
Dissolution of anhydrite and calcite cements was inferred from fluid analysis.
Sample permeability increased by a factor 2.

Abstract:

Flow-through experiments were performed in a newly designed experimental setup to study the water–rock interactions caused by CO₂ injection in sandstones obtained from the Altmark natural gas reservoir under the simulated reservoir conditions of 125°C and 50 bar CO₂ partial pressure. Two different sets of experiments were conducted using CO₂-saturated millipore water and CO₂-saturated brine (41.62 g L^-1 NaCl and 31.98 g L^-1 CaCl₂·2H₂O), mimicking the chemical composition of the reservoir formation water. The major components in the sandstone were quartz (clasts + cement), feldspars, clay minerals (illite and chlorite), and cements of carbonates and anhydrite. Fluid analysis suggested the predominant dissolution of anhydrite causing increased concentrations of calcium and sulfate at early time periods at non-equilibrium geochemical conditions. The Ca/SO₄ molar ratio (>1) indicated the concurrent dissolution of both calcite and anhydrite. Dissolution of feldspar and minor amounts of clay (chlorite) was also evident during the flow-through experiments. The permeability of the sample increased by a factor of two mostly due to the dissolution of rock cements during brine injection. Geochemical modeling suggests calcite dissolution as the major buffering process in the system. The results may in future studies be used for numerical simulations predicting CO₂ storage during injection in sandstone reservoirs.

Reaction vessel used in the CO2/brine/rock reaction experiments on the Altmark sandstone – courtesy Farhana Huq

I’m a Geoscientist: Suzanne Hangx – ‘Subsurface’ Officer

ERE Matters March 16, 2015

It’s I’m a Geoscientist week! Or more exactly: weeks. From March 9 until March 20, the EGU supports I’m a Geoscientist to help students engage with scientists about real science. The Energy, Resources and Environment Division of the European Geosciences Union encompasses a broad range of different ERE-related topics, from surface to subsurface, spanning all aspects of geosciences. In order to demonstrate how broad the Division actually is, and what you can do as a geoscientist to be involved with energy, resources or the environment, we asked the members of the ERE committee to introduce themselves and explain how their day-to-day work relates back to ERE.

From above ground, we will dive down below into the subsurface with Suzanne Hangx, post-doctoral researcher at the High Pressure and Temperature Laboratory at Utrecht University.

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In my research, I have always been driven by curiosity about the physical and chemical processes that control rock material behaviour in the subsurface, along with the direct relevance of this field to socially relevant issues. Naturally, working on energy, sustainability and the environment from a geoscientific point of view was a logical step. I want to contribute to solving geo-energy problems, by investigating and quantifying related risks, such as climate change caused by greenhouse gases or surface subsidence caused by oil/gas/ground water production, and contribute to socially acceptable solutions or technologies.

For about 10 years I have mainly been working on CO₂ Capture and Storage (CCS). It is considered to be one possible route to get rid of large quantities of CO₂ by injecting them into the subsurface, reducing its effect on climate change. Suitable locations are depleted oil or gas reservoirs, or aquifers, at several km’s below the surface. However, it is important to ensure that after injection the CO₂ also stays there – not just today or tomorrow, but for thousands of years. Once a potential injection site is suggested, it is important to see if the reservoir (the ‘container’) and the seal keeping the CO₂ in place (the ‘lid’), are up for the job, so to speak. I investigate if the injected CO₂ does anything to the rocks to alter their mechanical behaviour, i.e. how they break, under which force they break and if they get weaker by the presence of the CO₂.

When you inject CO₂ into a depleted oil or gas reservoir, part of it will start to dissolve into the water that is present in that reservoir, while the rest will stay in a dense liquid or supercritical phase. When CO₂ dissolves in water, the water will become acidic. This acidic fluid can chemically interact with the surrounding rocks, and certain minerals may dissolve and new ones may be formed. In addition, the way cracks propagate through the rock may be affected, changing their strength and the way they break. If a rock gets sufficiently weakened by the chemical interaction with CO₂ it may compact or break, which we would like to know in advance!

In Utah, natural CO2 accumulations are present within the Entrada Sandstone (‘Layer Cake’ by Suzanne Hangx, via ImagGeo)

Such chemical interactions may occur on different timescales. Processes that happen in days, weeks or months can still be dealt with in a laboratory setting. However, to be able to predict what will happen on the timescale of thousands of years, we are currently trying to learn as much as we can from naturally occurring CO₂ fields, such as those in Utah (USA), Australia and Europe. These fields can contain over 90% pure CO₂ and have mostly done so for thousands of years. Studying these fields can help us understand better how subsurface storage of anthropogenic CO₂ will evolve over time.

Nowadays I’m trying to apply what I learned during my research on the chemical-mechanical interactions occurring in rocks to understand surface subsidence, and related induced seismicity, resulting from the production of fluids such as oil and gas. Though dealing with a different setting, the mechanisms and processes are similar to those of interest for CCS. Given their interdisciplinary nature, the ERE sessions at the EGU General Assembly are the perfect platform for me to show my most recent research in both areas!

Words on Wednesday: A multi-model analysis of change in potential yield of major crops in China under climate change

ERE Matters March 4, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

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Yin, Y., Tang, Q., and Liu, X.: A multi-model analysis of change in potential yield of major crops in China under climate change, Earth Syst. Dynam., 6, 45-59, doi:10.5194/esd-6-45-2015, 2015

Abstract:

Climate change may affect crop growth and yield, which consequently casts a shadow of doubt over China’s food self-sufficiency efforts. In this study, we used the projections derived from four global gridded crop models (GGCropMs) to assess the effects of future climate change on the yields of the major crops (i.e., maize, rice, soybean and wheat) in China. The GGCropMs were forced with the bias-corrected climate data from five global climate models (GCMs) under Representative Concentration Pathway (RCP) 8.5, which were made available through the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). The results show that the potential yields of the crops would decrease in the 21st century without carbon dioxide (CO₂) fertilization effect. With the CO₂ effect, the potential yields of rice and soybean would increase, while the potential yields of maize and wheat would decrease. The uncertainty in yields resulting from the GGCropMs is larger than the uncertainty derived from GCMs in the greater part of China. Climate change may benefit rice and soybean yields in high-altitude and cold regions which are not in the current main agricultural area. However, the potential yields of maize, soybean and wheat may decrease in the major food production area. Development of new agronomic management strategies may be useful for coping with climate change in the areas with a high risk of yield reduction.

The MM of the relative change in the simulated yield of maize (a), rice (b), soybean (c) and wheat (d) with the CO2 effect at the end of the 21st century (2070–2099) compared with the simulated yield in the historical period (1981–2010).