Geochemical Modeling of Changes in Storage Rock Environments at CO2 Injection Sites (original) (raw)
Related papers
Energy Procedia, 2011
Over the past few years several geochemical evaluations of CO 2 storage in Dutch potential reservoirs are carried out, including predictions of the short-and long-term impact of CO 2 on the reservoir using geochemical modelling. The initial mineralogy of the reservoir is frequently obtained from core analysis and is then used to compute the formation water composition. In this paper geochemical modelling with TOUGHREACT is used to predict and compare the short-and long-term geochemical impact of CO 2 injection into three reservoirs. The mineralogical composition of these reservoirs is an assemblage based on commonly observed minerals from the Buntsandstein and Rotliegend formations. These formations contain potential onshore and offshore CO 2 storage locations in the Netherlands. The results predict drying out and salt precipitation in the near-well area, due to water evaporation by the injected dry CO 2 . Several mineral transformations are predicted, dominated by the transformation of albite into dawsonite, thereby fixing CO 2 . Due to the relatively low density of dawsonite, the porosity significantly decreases, which can lead to a pore pressure increase. Disabling of dawsonite precipitation in the simulations, thereby taking into account the ongoing debate on dawsonite stability, only shows a small increase of the porosity. Future (experimental) work should be focused on dawsonite occurrence for accurate predictions of the long-term reservoir integrity.
The presented results concern mnieralogic-petrographical investigations (XRD analysis, SEM analysis, microscopic observations in polarized light) of rock samples from drilling cores of Budziszewice structure (Zaosie and Buków boreholes) as a potential CO 2 storage site for Belchatów Power Plant, which is the largest in Poland and Europe brown coal combustion Power Plant. Examined samples represent Lower and Middle Jurassic rocks from potential reservoir formations (vari-grained quartz sandstones) and cap rocks (laminated mudstones and claystones), from depths of 838-1436 meters. Also the geochemical modeling with use of Geochemist's Workbench 7.0.1. package in two stages was performed. The main aim of the modeling was to determine the changes rock matrix and the reservoir parameters, that could occur due to CO 2 injection. The simulations allowed to determine the suitability of the formation for carbon dioxide storage. The first one was aimed at simulating the immediate changes in the aquifer and insulating rocks impacted by the beginning of CO 2 injection (100 days), the secondenabling assessment of long-term effects of sequestration (20 000 years).
Geochemical Interactions Between CO2, Pore-Waters and Reservoir Rocks
Nato Science Series: IV: Earth and Environmental Sciences, 2006
The degree of reactivity between CO 2 , pore-waters and minerals may have significant consequences on CO 2 storage capacity, the injection process, and long-term safety and stability. Geochemical reactions are highly site-specific and time-dependent. They need to be assessed on a site-to-site basis according to best practises by combining numerical modelling and observations from laboratory experiments, field monitoring, and natural analogues. A selection of lessons learned from three European projects about the reactivity of CO 2 with reservoir rocks and cap rocks is presented here for three sites: Sleipner (Norway) and Weyburn (Canada) where more than 1 Mt of CO 2 per year has been injected underground since 1996 and 2000 respectively, and Montmiral, a natural CO 2 field in France.
Geochemical modelling of formation damage risk during CO2 injection in saline aquifers
Journal of Natural Gas Science and Engineering, 2016
This study provides an understanding of the impact of geochemical reactions during and after CO 2 injection into a potential storage site. The results of calculations of geochemical reactivity of reservoir rock and of cap rock during and after CO 2 injection were performed using a geochemical simulator, with the calculations showing that for these conditions up to 0.5 moles of CO 2 can be dissolved per kg of water. The risk of dissolution of primary cements was considered and identified. In addition, the potential of carbonation reactions to permanently sequester CO 2 was considered, although these reactions were shown to be very slow relative to other processes. The implications for security of storage are that while dolomite nodules exist in the sandstone formation, these do not contribute significantly to the overall rock strength, and hence the risk of dissolution of the formation or caprock causing significant leakages pathways is very low. Further calculations were performed using a commercial reservoir simulation code to account for brine evaporation, halite precipitation and capillary pressure re-imbibition. The impact on injectivity was found not to be significant during continuous and sustained injection of CO 2 at a constant rate. Capillary pressure effects did cause re-imbibition of saline brine, and hence greater deposition, reducing the absolute porosity by up to 13%. The impact of the halite deposition was to channel the CO 2 , but for the configuration used there was not a significant change in injection pressure.
Earth and Space Science, 2015
The objective of this study was to determine the influence of the possible CO 2 geological storage in the Baltic Region on the composition and properties of host rocks to support more reliable petrophysical and geophysical models of CO 2 plume. The geochemical, mineralogical, and petrophysical evolution of reservoir sandstones of Cambrian Series 3 Deimena Formation and transitional clayey carbonate caprocks of Lower Ordovician Zebre Formation from two offshore structures in Latvia and Lithuania and two onshore structures in Latvia, induced by laboratory-simulated CO 2 geological storage, was studied for the first time in the Baltic Region. The geochemical, mineralogical, and petrophysical parameters were measured in 15 rock samples, before and after the alteration experiment. The diagenetic alterations of reservoir rocks were represented by carbonate cementation in the top of the onshore South Kandava structure, and quartz cementation and compaction, reducing the reservoir quality, in the deepest offshore E7 structure in Lithuania. The shallowest E6 structure offshore Latvia was least affected by diagenetic processes and had the best reservoir quality that was mainly preserved during the experiment. Carbonate cement was represented by calcite and ankerite in the transitional reservoir sandstones of very low initial permeability in the upper part of the South Kandava structure. Its dissolution caused a significant increase in the effective porosity and permeability of sandstones, a decrease in the weight of samples, bulk and matrix density, and P and S wave velocities, demonstrating short-term dissolution processes. Only slight geochemical changes occurred during the experiment in offshore reservoir sandstones. Minor dissolution of carbonate and clay cements, feldspar and some accessory minerals, and possible minor precipitation of pore-filling secondary minerals associated with slight variations in rock properties, demonstrating both short-term and long-term processes, were suggested. As a novelty, this research shows the relationship between diagenetic alterations of the Cambrian Series 3 Deimena Formation reservoir sandstones and their changes caused by the CO 2 injection-like experiment. Our study is focused on CO 2 storage in deep saline aquifers overlain by the caprock (seal). This is the most widespread worldwide option currently under consideration for CO 2 Geological Storage (CGS). The SHOGENOV ET AL. EXPERIMENTAL MODELING OF CO 2 STORAGE 262
Modelling of geochemical reactions during CO2 WAG injection on carbonate reservoirs
2018
In this thesis calcite dissolution and precipitation are investigated during injection of CO2 WAG (water alternating gas) in limestone oil reservoirs. First, the equilibrium between calcite and the carbonic acid system is studied in a static environment to understand how variations in chemical composition, temperature and pressure affect the mineral reactions. Then, four models of CO2 solubility are presented (PHREEQC, CMG GEM, Duan & Sun and Diamond & Akinfiev) and compared against experimental data from the literature. An empirical model that couples the CO2 solubility to the mineral and aqueous reactions is constructed. After that, reactive transport simulations are performed using PHREEQC and GEM. The injection of carbonated water in a limestone reservoir is simulated with PHREEQC to assess the behaviour of calcite reactions. The obtained results are explained and also observed in a similar model using GEM. Additional simulations are performed in GEM concerning single-phase inje...