Pressure control for managing and optimizing adjacent subsurface operations in large scale CCS

Injecting CO2 in to the subsurface for safe storage of CO2 the pressure propagates far away from the injection point and this can be a potential problem if the overpressure extents to neighbouring subsurface activities or potential leakage pathways. For structural closure trap configurations the CO2 plume is captured within the local structural closure but the pressure footprint is on a more regional scale. This rise the question on, how large the storage complex needs to be for any individual storage operations and how large an area monitoring activities have to cover. The EC CCS guidance document addresses the issues with statements on competitions between subsurface operations but returns no absolute values. Pressure modelling of CO2 injection process with state of the art reservoir simulation tools is challenges by use of realistic model boundary conditions in order to model a realistic pressure level. Combined use of models on a site scale and on a regional scale can instruct how boundary conditions are set-up for a site scale model. Pressure management through pressure release wells could be an option to mitigate undesirable over-pressure developments. For local structural closures the pressure release wells can be placed outside the closure hereby mitigate the overpressure without introducing a potential leakage by drilling inside the trap. The paper addresses the issue of selecting model boundary conditions and modelling mitigation of pressure development by use of a large regional model with local structural traps in the Bunter Sandstone Formation in the UK Southern North Sea

CO 2 Migration Monitoring Methodology in the Shallow Subsurface: Lessons Learned From the CO 2 FIELDLAB Project

International audienceA CO 2 migration field laboratory for testing of monitoring methods has been established in the glaciofluvial-glaciomarine Holocene deposits of the Svelvik ridge, near Oslo. A shallow CO 2 injection experiment was conducted in September 2011 in which approximately 1700 kg of CO 2 was injected at 18 m depth below surface. The objectives of this experiment were to (i) detect and, where possible, quantify migrated CO 2 concentrations, (ii) evaluate the sensitivity of the monitoring tools and (iii) study the impact of the vadose zone on measurements. This paper describes the injection, discusses the joint interpretation of the results and suggests some recommendations for further work

Efficiency of CO2 Foam Mobility Control with Heterogeneous Reservoir Properties

We investigate how reservoir heterogeneity affects the efficiency of CO2 mobility control in saline aquifer storage. An ensemble of reservoir models is set up for simulation of CO2 injection with a quarter-five-spot well pattern where CO2 is injected, and brine is produced for pressure control at opposite corners. Results with and without mobility control are compared. Additionally, results are generated for a modified foam model where the mobility reduction factor scales with reservoir permeability. An empirical foam model with partitioning of surfactant between the CO2 and brine phases is used.publishedVersio

The economic value of CO2 for EOR applications

While most works on CCS in connection with CO2 EOR credit all the benefit of the additional oil production to the CCS entity, this work investigate the impact of alternative EOR methods on the valuation on CO2 EOR storage. Based on a generic model suitable for CO2 EOR in Norwegian oil fields, EOR production with CO2 injection is compared to the EOR production with chemical EOR for different scenarios. The comparison shows that depending on the scenario combination considered the added value of using the CO2 EOR method instead of the chemical EOR method varies from -4 to 33 €/bblproduced equivalent to -4 to 56 €/tCO2,avoided. In most of the cases considered, the CO2 EOR method would therefore be preferred with however more or less value creation depending on the case. The evaluation shows that for an oil price minus the normal production costs equal to 50 €/bbl, the oil value which shall be considered for CO2 EOR application varies between 8 and 41 €/bbl, which can therefore be significantly lower than the 50 €/bbl which shall be considered if chemical EOR is not an alternative. The value one would be willing to pay to have CO2 delivered at a field varies between -4 and 56 €/tCO2 depending on the scenario combinations considered and can therefore also be significantly lower than in cases in which chemical EOR is not an alternative. For example, in the medium CO2 EOR scenario, the CO2 value is between 27 and 60% lower if chemical EOR is considered as an alternative option for EOR. As a consequence, a CCS chain including CO2 EOR would overestimate its benefits if it does not considered chemical EOR as an alternative to CO2 EOR for Oil & Gas companies. Finally, the sensitivity analyses identify the factors having the largest influence on the value one would be willing to pay to have CO2 delivered at its field

Efficiency of CO2 Foam Mobility Control with Heterogeneous Reservoir Properties

We investigate how reservoir heterogeneity affects the efficiency of CO2 mobility control in saline aquifer storage. An ensemble of reservoir models is set up for simulation of CO2 injection with a quarter-five-spot well pattern where CO2 is injected, and brine is produced for pressure control at opposite corners. Results with and without mobility control are compared. Additionally, results are generated for a modified foam model where the mobility reduction factor scales with reservoir permeability. An empirical foam model with partitioning of surfactant between the CO2 and brine phases is used

Storage Resources for Future European CCS Deployment; A Roadmap for a Horda CO2 Storage Hub, Offshore Norway

Deployment of Carbon Capture and Storage (CCS) at large scale will be necessary to be able to fulfil the goal from the Paris Agreement to keep the global mean temperature in year 2100 well below two degrees Celsius above preindustrial levels. Consequently, it is anticipated that there will be a significant increase in demand for CO2 storage capacity. Offshore areas, such as the North Sea part of the Norwegian Continental Shelf, are prime candidates to provide this storage capacity. Given that the development of a storage site can take five years or more, it is of major importance to start the planning of expandable storage hubs. Anticipating and planning of additional stores will give industry clusters and power producers confidence that there will be sufficient operative storage capacity available for the expected increasing supply of captured CO2. In this study, which is part of the ALIGN-CCUS project, we outline how an expansion in annual storage capacity of a CO2 storage hub offshore the west coast of Norway can be achieved. Simulation of CO2 storage and capacity estimates show that the Horda Platform study area has at least four potential storage sites with capacities in million tonnes (Mt) or thousand million tonnes (Gt) CO2 as follows: 1) Aurora structure, in the Johansen Formation, south-east of the Troll Gas Field (120–293 Mt); 2) Alpha structure, in the Sognefjord Formation, northern Smeaheia area (40–50 Mt); 3) Gamma structure, in the Sognefjord Formation, southern Smeaheia area (0.15–3 Gt) and 4) Troll Field, Sognefjord Formation, after cessation of gas production (3–5 Gt). We sketch a timeline for which possible sites could be used for the development of the industrial-scale Horda CO2 Storage Hub over the next thirty years. The annual storage capacity is matched to the estimated CO2 supply rates (million tonnes per year) from sources in Norway, Sweden and Northern Europe. These estimates indicate cumulative totals of CO2 stored in range of 810 Mt by 2050, and 1.85 Gt by 2065

Storage Readiness Levels: communicating the maturity of site technical understanding, permitting and planning needed for storage operations using CO2

A framework of Storage Readiness Levels (SRLs) is presented to communicate the entirety of technical appraisal, permitting and planning activities achieved at a potential CO2 storage site and what remains to be completed for CO2 storage operations. The schema, based on learning gained from the experience of researchers, regulators and industry from the 1990s, is described and assessed by application to 742 saline formation and hydrocarbon field sites, offshore the UK, Norway and The Netherlands. The framework is flexible to accommodate national differences in procedures and practise and the unique character of each site. It is applicable regardless of the time-scale of appraisal or scale of assessment. The framework is consistent with and extends the industry commercial project development classification to include categories for sites with a lesser level of data and evaluation. Application to the phases of appraisal of three sites illustrates that investigations may advance understanding by different pathways and rates. The standardised framework enables comparison of the experience of permitting and planning activities completed within different jurisdictions, the level of investment and the duration required to achieve permitted or permit-ready sites. It is intended that the framework of SRLs should be widely applied