Jon Peder Eliasson
Senior Research Scientist- Name
- Jon Peder Eliasson
- Title
- Senior Research Scientist
- Phone
- 473 69 732
- Department
- Petroleum
- Office
- Trondheim
- Company
- SINTEF AS
Reliable monitoring of a CO₂ storage site is essential for safe and efficient operation, as well as for public acceptance. By carefully monitoring the site before, during, and after CO₂ injection,the risk of very costly intervention, remediation, or site closure is significantly reduced. Such surveillance can potentially be very expensive.
The main ambition of Task 12 is to develop and demonstrate monitoring technology that will enable safe operation in compliance with laws and regulations in the most cost-effi cient manner.
To ensure optimal industry relevance and the highest possible relevance for the Northern Lights project (the carbon storage project of Equinor, Shell, and Total) on the Norwegian Continental Shelf, the industry will be closely involved through the lifetime of the Task. Involvement of vendors with expertise from oil and gas monitoring will also be important, and we will seek to have a dialogue with regulators.
Most of the monitoring activities in this Task are related to both Deployment Cases, since similar geophysical monitoring technologies are expected to be used in both cases.
The focus on methods for the optimal use of geophysical information continued, with further development of the method for rock physics inversion that this year focused on a framework for inversion based on selected machine learning algorithms. Four different algorithms were tested with respect to their efficiency at determining porosity, bulk and shear modulus from a velocity model.
Initial studies were also carried out to better understand the potential use of PS-converted seismic waves for the discrimination of pressure and saturation changes in the subsurface. The results were encouraging but obtained using a highly simplified synthetic model. The plan for 2022 is to carry out similar tests with a much more realistic model and potentially later with real data, adding significant complexity.
While much of the focus in Task 12 is on monitoring Norwegian CO₂ storage projects, a major study has also been initiated relateing to the characterization and modelling of the Bunter Sandstone Formation saline aquifer in the southern North Sea. In 2021, a model of the area was constructed and large-scale injection modelling carried out. Additional geomechanical modelling indicated a level of subsurface displacement that may be observed using InSAR if a suitable set of point sources overlay the region. It was pointed out that planned windfarms in the region may provide a suitable monitoring reflector to assess seabed movement. In addition, a set of seabed tiltmeters may provide the necessary resolution for the regional geomechanical monitoring.
Within the EM4CO2 project, some of the most important results include the demonstration of the feasibility of using CSEM for monitoring at Smeaheia, how CSEM survey layouts can be minimised without a loss of information, and how to account efficiently for infrastructure effects during EM modelling. The feasibility study showed promising results, with the CO₂ plume after 25 years of simulated injection being clearly visible on inversion results. Using a recently developed survey optimisation approach, it was also verified that a significantly reduced, but a wisely designed survey gave a nearly equally well imaged plume (see Figure 1). Another highlight in the EM4CO2 project was the recruitment of a postdoc researcher who will work on a new approach for time-lapse CSEM inversion.
For the TOPHOLE project, the year meant further work on the monitoring concept integrating the screening of legacy wells, and the localisation, characterisation and monitoring of these wells with non-invasive methods. The screening approach has been tested on a large number of wells in the Troll area (see Figure 2), and more recently as part of a detailed study for the Smeaheia structure, where the full concept has been applied. The interest in and need for this type of tool has resulted in plans for preparing a professional version of the tool during 2022. Experimental work has been started and is focusing on acoustic measurements on a well replica and testing the leakage detection abilities of accelerometers and fiberoptics. Ehsan Hosseini (NTNU PhD student) has been working on electromagnetic modelling of well signatures and effects of cement and corrosion on the recorded signals.
In 2020, effort was made to disseminate important recent results from the CO2 monitoring task of the NCCS centre.
The Bayesian Rock Physics Inversion technique (completed and demonstrated in 2019) and its application to Sleipner data was thoroughly described in a paper (“Combined geophysical and rock physics workflow for quantitative CO2 monitoring”) for the International Journal of Greenhouse Gas Control (IJGGC) that was accepted for publication at the end of the year. Similarly, another IJGGC paper, “Assessing the value of seismic monitoring of CO2 storage using simulations and statistical analysis”, summarizing previous work on a value-of-information assessment workflow was accepted for publication at the very end of the year.
At the beginning of the year, four abstracts were also sent to the GHGT conference, which was unfortunately delayed until 2021. All abstracts were accepted and draft papers have been written related to each of these topics.
One of the papers describes the current status of work done on combining monitoring data and reservoir simulations of CO2 storage sites for improved understanding of a storage site. The method, based on a flexible modelling framework in the open source Matlab Reservoir Simulation Toolbox (MRST), allows optimization of CO2 storage modelling to any combination of observed monitoring data. It has been applied to the new, layered, Sleipner benchmark model, which was optimised to fit plume outlines, gravity monitoring data and CO2 saturations inferred from joint full waveform and rock physics inversion with promising results.
Another GHGT draft paper describes how SINTEF's optAVO method can be used to map the extent of the CO2 plume and provide an estimate for seismic parameters for a synthetic Sleipner case. Using the results (a P-wave model) of the optAVO as an initial model for Full Waveform Inversion (FWI) was seen to significantly improve the final FWI results.
The two other GHGT draft papers focused on monitoring at Smeaheia; one about application of a workflow for baseline quantitative characterisation using synthetic and real data from Smeaheia and one about a feasibility study on marine CSEM monitoring of CO2 flow along the Vette Fault. This latter study is the first of its kind as the only previous evidence of the efficiency of CSEM for detection of CO2 flow through faults/fractures was made through a laboratory test. The work has resulted in knowledge about how the CSEM data may interact with CO2 flow through the Vette Fault. Issues for which the CSEM technique should be improved were also identified.
Two successful webinars were carried out in 2020, both with a focus on more novel and unconventional technologies for CO2 monitoring. The spring webinar summarized work done within the task related to "A machine learning based monitoring framework for CO2 storage". The approach is based on integration of reservoir modelling, geophysical monitoring, and decision-making theory, and it was shown that a neural network can be trained to optimize geophysical data acquisition in terms of its value for verification of site performance. This is a first step towards a novel AI-based technique to support the decision-making process related to cost-efficient MMV. The autumn webinar, with nearly 230 registered, had a more general look at "Safe and cost-efficient CO2 storage: Emerging monitoring technologies" with an overview of what we see as promising future techniques. An informal survey on the view of the participants was also carried out.
In addition to this survey of emerging technologies, two smaller studies were carried out in 2020 to investigate the potential of using ECCSEL infrastructure in future work within the monitoring task.
The first investigated the possibility and usefulness of performing measurements of elastic and electric parameters at controlled laboratory and test site conditions in order to explore the physics and the interrelationships of these parameters as functions of saturation, pressure and temperature. Such measurements will contribute to calibrating rock physics models and would consequently result in more reliable interpretation of monitoring data. Several potential research tasks were suggested. Similarly, a study of potential research efforts on development and testing of fibre-optic (DAS/DTS/DSS) technology was carried out. This emerging monitoring technology is still not properly explored for CO2 monitoring purposes.
The recently upgraded Svelvik CO2 Field Lab has several monitoring wells instrumented with various types of optical fibres and offers great possibilities for such studies. A number of potential research tasks and spin-off projects have been suggested for the next few years in NCCS.
Reliable monitoring of a CO2 storage site is essential for safe and efficient operation, as well as for public acceptance. By carefully monitoring the site before, during, and after CO2 injection, the risk for very costly intervention, remediation, or site closure is significantly reduced. Such surveillance can potentially be very expensive. The main ambition of Task 12 is to develop and demonstrate monitoring technology which will enable safe operation in compliance with laws and regulations in the most cost-efficient manner.
During the year, we applied a newly developed approach for reservoir parameter estimation with uncertainty quantification (Bayesian Rock Physics Inversion) to Sleipner 2008 seismic data. We demonstrated how important reservoir parameters, such as CO2 saturation and reservoir pressure, can be estimated with a simultaneous assessment of uncertainty, providing essential operational information to the storage site owner. Initial studies also showed how the estimated reservoir parameters can be used to constrain and calibrate reservoir simulations of the Sleipner injection. This calibration enables improved prediction of the future behaviour of the storage site.
The development and testing of a compressive sensing technique for enhanced geophysical data acquisition and interpretation continued in 2019. This technique, which can help to reduce the need for dense (and expensive) seismic surveys, was succesfully verified for sparse subsets of Sleipner data.
Reliable and cost-efficient monitoring will be essential for the Northern Lights project. Task 12 developments like the ones described above will support the design of an optimal monitoring scheme. Another such example is how the research and development of Controlled Source Electro-Magnetics (CSEM), as a complement to seismic, could provide a more cost-efficient and accurate approach for quantitative CO2 monitoring. Based on synthetic Smeaheia data, a quantitative CSEM inversion study was successfully concluded in 2019 (see the figure). Results show that CSEM can be used to give accurate volume estimates.
For any future storage project, there is also a great value in the research efforts on value-of-information, which offer new ways for an operator to analyse and select optimal geophysical monitoring strategies. During 2019, a conceptual Smeaheia case was used to demonstrate how a novel method for value-of- information analysis, based on machine learning, can be used to determine the optimal way of detecting potential leakage from CO2 storage.
In 2019, we also initialised two spin-off projects (EM4CO2 and Tophole) for more detailed studies of two important topics. EM4CO2 investigates the use of electro-magnetic methods as a complement to seismic for more quantitative reservoir monitoring information. Tophole studies how the integrity of plugged and abandoned wells can be cost-effectively monitored to enable CO2 storage in regions with existing wells.
The task focused on setting up synthetic Smeaheia geophysical models, on developing new approaches for efficient use of available data for quantitative CO2 monitoring, and on using a statistical value-of-information concept for cost-minimization of CO2 monitoring.
For Smeaheia, Statoil's CO2 injection simulations were used to build synthetic models of the subsurface acoustic velocity, resistivity, and density at different times during and after the injection. These models together with Smeaheia data provided by Gassnova will serve as very important input for targeted Smeaheia monitoring studies in the years to come in NCCS.
Work on quantitative CO2 monitoring at Sleipner led to promising results that was presented at several workshops and conferences and published in several journals. In total, six publications were produced.
Industry partners Statoil, Shell and Total, as well as vendor Quad Geometrics have contributed to the task and participated in a workshop in September. Late in 2017, EMGS confirmed that they want to join the task as a vendor.
During 2021, Task 12 and its associated spin-off projects EM4CO2 and TOPHOLE successfully published several important research results. In addition to publishing papers on “Combined geophysical and rock physics workflow for quantitative CO₂ monitoring” and on “Assessing the value of seismic monitoring of CO₂ storage using simulations and statistical analysis” (both in the International Journal of Greenhouse Gas Control (IJGGC) and submitted already in 2020), several other studies culminated in publications:
Journal Publications
2018:
2017:
Conference Publications
2018: