EAGE Workshop on Carbon Capture and Storage (CCS) in Basalts

The study assesses the CO2 storage potential of DVP in terms of quantifying the carbonates precipitated by using Python. The study develops a model based on general stoichiometric chemical reactions and Henry’s law that determines the mass of reaction products in moles. The model will be further validated the experimental data that will include reacting basalt powders with carbonic acids. The model is primitive in nature and can be advanced as per the requirements.

Here, we describe the testing of geophysical techniques to monitor and evaluate a pilot site for in-situ CO2 mineral storage in Helguvik, Iceland. In addition to hydraulic spinner tests and borehole logging data, the stratigraphic sequence of the reservoir was characterized using drill cutting samples. The porosity network and flow characteristics of drill cores were examined in laboratory both before and after they were exposed to saline water that was enriched with CO2. Both before and during injection operations, cross-hole seismic measurements were carried out. At the same time, all of the wells underwent single-hole electrical resistivity measurements.

A seismic array of 3D nodal geophones and a backbone seismic network positioned around the injection site were used to monitor the background seismicity and any seismicity that might have been caused by the injection activities.

The datasets depict a coherent and detailed image of the targeted reservoir.

The Deccan Basalt formation in the Deccan Volcanic Province offers significant potential for geologic carbon sequestration (GCS) due to its extensive coverage and unique mineral composition. Previous studies estimate that the region could store between 94 and 305 gigatonnes of CO2, making it a key candidate for carbon mitigation in India. However, understanding the factors influencing CO2 migration, trapping mechanisms, and mineral carbonation in these basalt formations remains an area of ongoing research. This study builds on prior work by investigating how temperature, pressure, pH, petrophysical properties, and CO2 injection strategies affect the efficiency of mineral carbonation in the Deccan Basalt over 250 years. Using multiphase and multicomponent reactive transport modeling, the study examines the role of various minerals (including albite, anorthite, and diopside) in CO2 sequestration under different reservoir conditions. Results indicate that CO2 trapping is most effective under moderate temperature and pressure, with anorthite being the most reactive. Cyclic CO2 injection outperforms continuous injection, enhancing mineral precipitation and clay formation. The study concludes that CO2 sequestration in Deccan basalt is viable with proper management and monitoring, though site-specific studies are needed for practical implementation. Further research on mineral variations and microbial effects on carbonation is recommended.

CO2 mineralization in mafic and ultramafic rocks represents a potential method of rapid and secure carbon sequestration. Whilst the technology is relatively immature compared to saline aquifers and depleted fields, an approach to enable the rapid identification of areas of high potential is required to expediate the process of site selection. Here we present a global screening approach that encompasses several in-house datasets for the screening of potential for both in-situ and surficial methodologies. The in-situ process considers tectonic setting alongside surface lithology and whole rock geochemistry data to begin to identify areas that are likely to be prospective for mafic and ultramafic rocks, whilst the surficial approach considers the likely geochemistry of mine tailings alongside production volumes to begin to high-grade current and historic mines. Insights from both methodologies are realized rapidly and can be scaled to a more local scale where suitable, enabling the acceleration of initial site selection workflows.

Mitigating climate change requires strategies to reduce greenhouse gases from human activities. Carbon Capture and Storage (CCS) is a promising solution, provided suitable CO2 reservoirs are identified. Basalts are increasingly considered for CO2 storage due to their heterogeneous internal structure, connected vesicles, and high content of reactive minerals, which permanently sequester CO2 faster through mineral trapping than sedimentary rocks.

Immiscible two-phase flow in basalts is presumably very different compared to sedimentary rocks because of the large heterogeneity in pore sizes. However, important multi-phase flow properties such as relative permeability and capillary pressure remain poorly constrained in basalts. In this study, we use computational fluid dynamics with the Volume of Fluid (VOF) method to track the evolution of fluid-fluid interfaces. Three-dimensional X-ray micro-computed tomography (μCΤ) images of a range of pore geometries were used to simulate two-phase flow under capillary-dominated flow rates. The results were used to determine pore-scale capillary pressure (Pc) under dynamic conditions where the interfaces do not reach equilibrium. Analysis suggested that the Pc is influenced by the pore structure and size, and by the interfacial tension between the two fluid phases. This approach offers insights into preferential sites for mineralization which help predict CO2 migration and trapping.

Carbon Capture and Storage (CCS) is crucial for reducing emissions in hard-to-decarbonize sectors such as cement, steel, and power generation. For India, heavily reliant on coal, CCS provides a means to lower emissions while maintaining energy security. While global CCS deployment has gained momentum through policy support and funding, high costs remain a significant challenge. In India, basalt formations, especially in the Deccan Traps, present a promising and cost-effective option for CO2 storage through mineralization. India’s CCS policy is still in development, with short-term incentives like carbon credits and potential long-term goals, such as carbon taxes, being considered. To scale CCS, India requires robust funding mechanisms, technological innovation, and large¬scale CCS clusters. International collaboration and investment will be essential in addressing financial and technological barriers. With the right infrastructure, research, and policy framework, CCS can become a key component of India’s strategy to meet its net-zero target by 2070.

Stretched across 500,000 km2 in west-central India, the Deccan Traps have been recently identified as a potential site for safely and permanently trapping about hundred Gtons per year of CO2 through mineral carbonation, according to recent geochemical and mineralogical studies. However, limited data on the geophysical, petrophysical and geomechanical properties of the various basaltic lithotypes present in the area have been collected. These properties are crucial for an effective and quantitative evaluation of the site’s suitability for carbon mineralisation.

In order to fill in this knowledge gap, we performed an experimental framework for the petrophysical and rock mechanical characterisation of two different lithofacies (flow-top brecciated and massive) of basaltic rocks collected from the Deccan Volcanic Province. The research was conducted at the Geomechanics and Geophysics Laboratory (GGL) at ARRC, CSIRO Energy, Western Australia.

Starting with sample preparation and CT-scanned imaging of the samples, geophysical and petrophysical properties (including bulk density, acoustic velocities, porosity and permeability) have been quantified. Hydrostatic and multi-stage triaxial tests under in-situ conditions (pressure/temperature) have also been conducted to characterise the rock mechanical properties of the basalt samples. This paper summarises the petrophysical and dynamic elastic moduli obtained for a selected suite of samples.

One of the most recent approaches for achieving enduring and scalable storage of CO2 is geological sequestration. The carbon dioxide can then be stored in subsurface basalt in the form of secondary carbonates through mineral carbonation reactions, providing a safe storage solution with minimal risk of leakage. Before initiating any pilot project, it is crucial to thoroughly comprehend the three-dimensional subsurface architecture, encompassing both vertical and lateral heterogeneities of the storage site. The availability of data concerning the subsurface structure of Deccan basalt, including the proportion of massive versus porous segments in-flows, as well as the lateral and vertical facies heterogeneity, is restricted. Outcrop analogues offer a valuable chance to reduce uncertainties in the subsurface by examining architectural features, including vertical and lateral facies variations within flows. This study highlights the workflow and results of characterizing flow heterogeneities in the outcrop model, along with laboratory analysis. For the first time, the research demonstrated the application of drone-driven photogrammetry in a carbon storage project.

Keeping into consideration the areal and voluminal extent of the Deccan basalt and its reactivity, it has a high potential to store CO2 in the form of stable carbonate minerals. In our work, we have reacted CO2 dissolved in water with basalt containing olivine, pyroxene, and plagioclase under different temperature conditions at 50 bar pressure to study the effect of temperature on mineral carbonation. We have also studied the effect of surface area of rock on mineral carbonation. For this, we have done a field study, petrography, XRF analysis, EPMA analysis, SEM analysis, and TGA analysis of the sample. In our study, we have found the formation of magnesite in powdered samples in a shorter duration (2 weeks) than stub samples (2 months) having 1 cm3 volume. This study also reveals more tendency to form carbonate minerals at higher temperatures compared to lower temperature.