Energy, Resources and the Environment

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

In NY Times: Butting Heads in the Himalayas

ERE Matters May 19, 2015

The environment we live in is shaped by many factors. It is not just how we use the land, resources and energy that is provided to us, there may also be factors that are simply out of our control. In recent weeks, this has become painfully clear in the area near Kathmandu, Nepal. Two devastating earthquakes have taken place within only a short amount of time, leaving a trail of destruction. We know that these earthquakes are the result of India moving towards the Eurasian continent, but what is driving India to move so fast, ploughing though the Earth’s crust like a bulldozer? Just like India is butting heads with Eurasia in the Himalayas, scienstists seem to be butting heads over the Himalayas, with multiple hypotheses trying to explain the complicated plate tectonics in the area…

Want to know more? Read all about it in this article in the New York Times! 🙂

Sunset from 20,000 feet on Mount Ama Dablam, Nepal – photo by Suzanne Imber (taken from ImagGeo)

From EGU to the Real World: meet ERE Young Scientist Farhana Huq

ERE Matters May 18, 2015

The ERE Division loves to hear from its Young/Early Career Scientists. What is it that you do that relates to ERE? What lies beyond an ERE-oriented study or PhD? Tell us what you like about working on Energy, Resources and Environment-related research. We’d love to hear it! 🙂

Today we have Farhana Huq, who gives us some insight into how her PhD project lead to a job on the boundary between academia and industry, and what she likes about attending the EGU General Assembly.

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Just as an introduction, I am Farhana from Bangladesh, working as a scientist at the Institute for Energy Technology in Norway. During my PhD research, I studied the chemical changes in rock and fluid composition upon CO₂ injection under simulated reservoir conditions on the laboratory scale. This project was performed under the framework of the BMBF CLEAN project, which aimed at understanding large-scale enhanced gas recovery by CO₂ injection into the Altmark natural gas reservoir, Germany.

My current research activities are mostly focused on CO₂ storage and monitoring techniques with oil and gas industries. I am involved in developing different monitoring techniques using solid sorbents and tracer solutions. Recently my interest shifted quite a lot to stable isotope techniques and gas geochemistry and applications of it into field scale.

EGU has always been a great platform for me to meet new people, making contacts, learning on different topics, exchanging ideas and last but not least making wonderful friends. Starting from 2010 till now, I have tried to attend EGU sessions regularly and mostly contributed in ERE division sessions by presenting posters. Every time, I returned home with very good ideas, suggestions and constructive criticism from scientists from all over the world. This year was special as I was the young scientist representative for the ERE division, as a replacement for Sian, which gave me a huge opportunity to meet young and energetic scientists from various research fields. I wish and suggest to have more meetings and activities related to collaboration, networking, workshops and training within the young scientist forum.

EGU is not just for science, but also a great way to meet new friends!

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Do you also want to be featured on ERE Matters? Just fill out the Submit a Post form, or drop us an email at ere.matters@gmail.com!

What to see at EGU?: Words on Wednesday – The Green River Natural Analogue as A Field Laboratory To Study the Long-term Fate of CO2 in the subsurface

ERE Matters April 8, 2015

If you are interested in today’s WoW, some of the results will be presented during the EGU in session ERE5.2 Field methods and analysis of field data for CO2 geological storage, on Thursday at 15.30h in room R8. So go check it out! 🙂

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Busch, A. Kampman, N. Hangx, S.J.T., Snippe, J., Bickle, M. Bertier, P., Chapman, H., Spiers, C.J., Pijnenburg, R.Samuelson, J. Evans, J.P., Maskell, A., Nicholl, J., Pipich, V., Di, Z., Rother, G., Schaller, M., 2014. The Green River Natural Analogue as a field laboratory to study the long-term faith of CO₂ in the subsurface. Energy Procedia 63, 2821-2830.

Abstract:

Understanding the long-term response of CO₂ injected into porous reservoirs is one of the most important aspects to demonstrate safe and permanent storage. In order to provide quantitative constraints on the long-term impacts of CO₂-charged fluids on the integrity of reservoir-caprock systems we recovered some 300m of core from a scientific drill hole through a natural CO₂ reservoir, near Green River, Utah. We obtained geomechanical, mineralogical, geochemical, petrophysical and mineralogical laboratory data along the entire length of the core and from non CO₂-charged control samples. Furthermore, we performed more detailed studies through portions of low permeability layers in direct contact with CO₂-charged layers. This was done to constrain the nature and penetration depths of CO₂-promoted fluid-mineral reaction fronts. The major reactions identified include the dissolution of diagenetic dolomite cements and hematite grain coatings, and the precipitation of ankerite and pyrite and have been used as input for geochemical 1D reactive transport modelling, to constrain the magnitude and velocity of the mineral-fluid reaction front.

In addition, we compared geomechanical data from the CO₂-exposed core and related unreacted control samples to assess the mechanical stability of reservoir and seal rocks in a CO₂ storage complex following mineral dissolution and precipitation for thousands of years. The obtained mechanical parameters were coupled to mineralogy and porosity. Key aim of this work was to better quantify the effect of long-term chemical CO₂/brine/rock interactions on the mechanical strength and elastic properties of the studied formations.

Entrada formation from surface to top Carmel Fm with CO2-charged sandstone layer, overlain by a low permeability clayey siltstone showing bleaching and CO2 reaction features. A sharp contact between bleached and unbleached is observed.