Monitoring Carbon Capture in Deep Rock using Muon Tomography

Transcription

1 Monitoring Carbon Capture in Deep Rock using Muon Tomography Cora Fung Supervisors: Vitaly Kudryavtsev, Neil Spooner

2 What is Carbon Capture and Storage (CCS)? B Metz, O.D., H C de Coninck, M Loos IPCC special report on Carbon Dioxide Capture and Storage, L.A. Meyer, Editor. 2005, IPCC AnytechnologiesdesignedtocaptureCO 2,eitherbeforeorafter combustion,andtostorethecapturedco 2,eitherbyphysicalor chemical means. It serves as an intermediate solution when switching the main energy source from mainly fossil fuel to mainly renewable.

3 Geological Carbon Storage B Metz, O.D., H C de Coninck, M Loos IPCC special report on Carbon Dioxide Capture and Storage, L.A. Meyer, Editor. 2005, IPCC

4 Monitoring Techniques Why are monitoring techniques necessary? B Metz, O.D., H C de Coninck, M Loos IPCC special report on Carbon Dioxide Capture and Storage, L.A. Meyer, Editor. 2005, IPCC To detect leak To gain more knowledge on possible storage mechanisms, migration of CO 2 Different techniques have different advantages and shortcomings, multiple techniques are used in one site Current available monitoring techniques: Soil sampling, time-lapse seismic, time-lapse gravity, well logging, electromagnetic surveys, tracer injection

5 Muons are charged, very penetrating particles created by cosmic radiation striking the atmosphere What are Muons? Muon Properties Loss energy through ionisation when travelling through matter Can be deflected when travelling through high atomic number materials

6 How are muon properties being exploited and developed into muon tomography? Energy loss depends on length travelled and the density of the material muons travelled through By detecting muon intensity, the density change of hidden terrain can be detected, hence hidden terrain can be visualised Muons can be deflected when travelling high atomic number materials Deflected muons can provide an image of hidden radioactive materials such as dirty bombs, which have high atomic numbers

7 Muon tomography as a CCS monitoring technique How does it work? In case of leak or CO 2 migration, density of reservoir will decrease, which could be signified by an increase of muon intensity at the bottom of the reservoir Why use muon tomography? Current monitoring technologies mainly depends on artificial input sources (e.g. tracer, seismic wave) to obtain response signals As there is a constant rain of muons on earth, extra input is not required, hence reduces probability of errors and costs

8 Possible problem How effective will it be? Muon intensity will be weaken with increased depth, hence sensitivity will be lowered Performance Prediction Calculations were carried out using the computer code MUSUN in order to assess sensitivity of muon detectors in different situations Three sets of calculations are set up: Different depths and operation time: By how much sensitivity changes between the shallowest (1km) and deepest (2km) storage site Detectors with different dimensions: By how much can sensitivity be improved using a larger detector A semi-realistic situation: using real geological parameters of an existing site with assumptions, predict how sensitive the detector would be when working in a close-to-real situation

9 Sensitivity of Detector at Different Depths The expected number of muons detected in 1 year drops by 98.6% as the detector moved from 1km to 2km underground. Expected Muon Intensity in 1 year at 1km At 2km, the muon detector is not sensitive enough to detect any leak unless the operation time is extended to 10 years (taking 1 reading every 5 years) Expected Muon Intensity in 1 year at 2km

10 Sensitivity of Detector with Different Operation Time Sensitivityof Detector in terms of%co 2 loss Operation time 1km underground 2km underground 2 Years 15% Incapableof detecting leaks 4Years 11% Incapable of detecting leaks 10 Years 6% 75%

11 Sensitivity of Detector of Different Dimensions Dimensionsof Detectors and their sensitivity in terms of %CO 2 loss Dimension (m m m) Top Surface Area (m 2 ) Original Design Design 1 Design 2 Design Sensitivity 75% 84% 62% 44%

12 Muon Detector Working in Semi-realistic Condition Geological parameters of Sleipner, Norway are used in this set of calculations Sleipneris the first commercialised carbon storage site aims to reduce carbon emission, hence most required data are available It is assumed that no water is present in the reservoir as there was not enough data to estimate. However, the calculations should still gives a rough picture of how the detector would perform in real life. The depth of the storage site is 1250m Detector used in this model is the original 1m 1m 1m design

13 Muon Detector Working in Semi-realistic Condition In this condition, the muon detector is sensitive to: 13% CO 2 loss with an operation time of 2 years 9%CO 2 loss with an operation time of 4 years. Expected Muon Intensity in 1 year Expected Muon Intensity in 2 year Detector has better sensitivity with semi-realistic setup comparing to previous calculations Although results might be too optimistic as water present in the reservoir is discounted.

14 Conclusions Using muon tomography as a carbon capture monitoring technique could reduce probability of errors and cost, as muons are free in the atmosphere It could be an effective monitoring technique in certain conditions More detailed calculations should be conducted in order to optimise the design of detector For improved accuracy, muon tomography should be used as a long-term monitoring technology.

15 Questions?