ASSESSING RISK IN CO2 STORAGE PROJECTS

2004 ◽  
Vol 44 (1) ◽  
pp. 677 ◽  
Author(s):  
A.R. Bowden ◽  
A. Rigg
Keyword(s):  
Risk Assessment ◽  
Best Practice ◽  
Co2 Storage ◽  
Assessment Method ◽  
Assessment Process ◽  
Co2 Injection ◽  
Base Case ◽  
Environmental Damage ◽  
Storage Site ◽  
Geological Storage

A key challenge to researchers involved with geological storage of CO2 has been to develop an appropriate methodology to assess and compare alternative CO2 injection projects on the basis of risk. Technical aspects, such as the risk of leakage and the effectiveness of the intended reservoir, clearly need to be considered, but so do less tangible aspects such as the value and safety of geological storage of CO2, and potential impacts on the community and environment.The RISQUE method has been applied and found to be an appropriate approach to deliver a transparent risk assessment process that can interface with the wider community and allow stakeholders to assess whether the CO2 injection process is safe, measurable and verifiable and whether a selected alternative delivers cost-effective greenhouse benefits.In Australia, under the GEODISC program, the approach was applied to assess the risk posed by conceptual CO2 injection projects in four selected areas: Dongara, Petrel, Gippsland and Carnarvon. The assessment derived outputs that address key project performance indicators that:are useful to compare projects;include technical, economic and community risk events;assist communication of risk to stakeholders;can be incorporated into risk management design of injection projects; andhelp identify specific areas for future research.The approach is to use quantitative techniques to characterise risk in terms of both the likelihood of identified risk events occurring (such as CO2 escape and inadequate injectivity into the storage site) and of their consequences (such as environmental damage and loss of life). The approach integrates current best practice risk assessment methods with best available information provided by an expert panel.The results clearly showed the relationships between containment and effectiveness for all of the four conceptual CO2 injection projects and indicated their acceptability with respect to two KPIs. Benefit-cost analysis showed which projects would probably be viable considering base-case economics, greenhouse benefits, and also the case after risk is taken into account. A societal risk profile was derived to compare the public safety risk posed by the injection projects with commonly accepted engineering target guidelines used for dams. The levels of amenity risk posed to the community by the projects were assessed, and their acceptability with respect to the specific KPI was evaluated.The risk assessment method and structure that was used should be applied to other potential CO2 injection sites to compare and rank their suitability, and to assist selection of the most appropriate site for any injection project. These sites can be reassessed at any time, as further information becomes available.

Reservoir Characterization for Uncertainty Analysis and Its Impact on CO2 Injection and Sequestration in a Depleted Offshore Carbonate Gas Field

2021 ◽  
Author(s):  
Debasis P. Das ◽  
Parimal A. Patil ◽  
Pankaj K. Tiwari ◽  
Renato J Leite ◽  
Raj Deo Tewari
Keyword(s):  
Co2 Storage ◽  
Assessment Process ◽  
Rock Properties ◽  
Co2 Injection ◽  
Storage Site ◽  
Reservoir Pressure ◽  
Gas Field ◽  
Well Integrity ◽  
Seismic Anomalies

Abstract The emerging global climate change policies have necessitated the strategic need for prudent management of produced contaminants and, with cold flaring being no more the best option, Carbon Capture Utilization & Storage (CCUS) technology provides opportunity for development of high CO2 contaminant fields. A typical CO2 sequestration project comprises capturing CO2 by separating from produced hydrocarbons followed by injection of CO2 into deep geological formations for long term storage. While injection ofCO2 may continue over tens of years, the long-term containment needs to be ascertained for thousands of years. Several geological and geophysical factors along with the existingwells need to be evaluated to assess the potential risks for CO2 leakage that maychallenge the long-term containment. This study considers a depleted carbonate field located offshore Sarawak as a possible long-term CO2 storage site. Elements that may lead to possible leakage of CO2over time are the existing faults or fractures, development of new fractures/faults during injection, caprock failure due to pressures exceeding fracture pressure during/after injection and possible leakage through existing wells. The risk assessment process includes identification and mapping of faults and fracture networks, mapping of seals, evaluation of seismic anomalies and gas while drilling records, pore-pressure analysis, laboratory experiments for analyzing changes in geomechanical & geochemical rock properties and well integrity of existing wells. All these parameters are cross correlated, and qualitative risk categorization is carried out to determine the robustness of the reservoir for long term CO2 storage. The evaluation of available data indicates less frequent faulting occur only towards the flank with no seismic anomalies associated with them. Some seismic anomalies are observed at shallower levels, however their impact on the reservoir and overburden integrity is assessed to be minimum. There are four shale dominated formations mapped in the overburden section, which will act as potential seals. Estimated fracture pressures for the potential seals ranges between 6200-9280 psia for the deepest seal to 2910-4290 psia for the shallowest. Therefore,it is interpreted that if the post injection reservoir pressure is kept below the initial reservoir pressure of 4480 psia, it would not hold any threat to the caprock integrity.Leakage rate riskalong the existing wells was determined based on well log data. Well integrity check of legacywells helped identify two abandoned wells for rigorous remediation to restore their integrity. The subsurface risk analysis is critical to ascertain the long-term containment of injectedCO2. The integrated subsurface characterization and well integrity analysis approach adopted in this work can be applied to any other field/reservoir to validate its robustness for long-term CO2 injection and storage.

scholarly journals Directional Hydraulic Characteristics of Reservoir Rocks for CO2 Geological Storage in the Pohang Basin, Southeast Korea

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2211
Author(s):  
Junhyung Choi ◽  
Kyungbook Lee ◽  
Young Jae Shinn ◽  
Seil Ki ◽  
Dae Sung Lee
Keyword(s):  
Reservoir Characterization ◽  
Co2 Storage ◽  
Rapid Screening ◽  
Co2 Injection ◽  
Storage Site ◽  
Geological Storage ◽  
Co2 Geological Storage ◽  
Injection Efficiency ◽  
Migration Pathway ◽  
Confining Pressures

This study conducted core sampling of an offshore borehole for geological reservoir characterization of a potential CO2 storage site in southeast Korea. From this, two promising geological formations at ~739 and ~779 m were identified as prospective CO2 storage reservoirs. Injection efficiency and CO2 migration were evaluated based on directional measurements of permeabilities from core plugs. The directional transport properties were determined using both a portable probe permeameter and a pressure cell capable of applying different in situ confining pressures. Both steady state and unsteady state measurements were used to determine permeability—the method selected according to the expected permeability range of the specific sample. This expected range was based on rapid screening measurements acquired using a portable probe permeameter (PPP). Anticipated performance of the prototypical CO2 injection site was evaluated based on flow modeling of the CO2 plume migration pathway including CO2 transport through the overlying formations based on the measured directional hydraulic properties. These analyses revealed that the injection efficiency at a depth of 739 m was double that at 779 m. These correlations among and distributions of the directional permeabilities of the potential CO2 geological storage site can be utilized for the assessment of CO2 storage capacity, injectivity, and leakage risk.

scholarly journals A Methodology for Harmonizing Safety and Health Scales in Occupational Risk Assessment

2021 ◽  
Vol 18 (9) ◽  
pp. 4849
Author(s):  
Zuzhen Ji ◽  
Dirk Pons ◽  
John Pearse
Keyword(s):  
Risk Assessment ◽  
Health And Safety ◽  
Assessment Method ◽  
Assessment Process ◽  
Successful Implementation ◽  
Health Issues ◽  
Public Health Perspective ◽  
Chronic Health ◽  
Risk Assessment Method

Successful implementation of Health and Safety (H&S) systems requires an effective mechanism to assess risk. Existing methods focus primarily on measuring the safety aspect; the risk of an accident is determined based on the product of severity of consequence and likelihood of the incident arising. The health component, i.e., chronic harm, is more difficult to assess. Partially, this is due to both consequences and the likelihood of health issues, which may be indeterminate. There is a need to develop a quantitative risk measurement for H&S risk management and with better representation for chronic health issues. The present paper has approached this from a different direction, by adopting a public health perspective of quality of life. We have then changed the risk assessment process to accommodate this. This was then applied to a case study. The case study showed that merely including the chronic harm scales appeared to be sufficient to elicit a more detailed consideration of hazards for chronic harm. This suggests that people are not insensitive to chronic harm hazards, but benefit from having a framework in which to communicate them. A method has been devised to harmonize safety and harm risk assessments. The result was a comprehensive risk assessment method with consideration of safety accidents and chronic health issues. This has the potential to benefit industry by making chronic harm more visible and hence more preventable.

scholarly journals The potential for large-scale, subsurface geological CO2 storage in Denmark

1969 ◽  
Vol 17 ◽  
pp. 13-16 ◽  
Author(s):  
Peter Frykman ◽  
Lars Henrik Nielsen ◽  
Thomas Vangkilde-Pedersen
Keyword(s):  
Carbon Capture ◽  
Large Scale ◽  
Best Practice ◽  
Co2 Storage ◽  
Carbon Capture And Storage ◽  
The European Union ◽  
Geological Storage ◽  
Geological Co2 Storage ◽  
Research Programmes ◽  
Capture Techniques

Carbon capture and storage (CCS) is increasingly considered to be a tool that can significantly reduce the emission of CO2. It is viewed as a technology that can contribute to a substantial, global reduction of emitted CO2 within the timeframe that seems available for mitigating the effects of present and continued emission. In order to develop the CCS method the European Union (EU) has supported research programmes for more than a decade, which focus on capture techniques, transport and geological storage. The results of the numerous research projects on geological storage are summarised in a comprehensive best practice manual outlining guidelines for storage in saline aquifers (Chadwick et al. 2008). A detailed directive for geological storage is under implementation (European Commission 2009), and the EU has furthermore established a programme for supporting the development of more than ten large-scale demonstration plants throughout Europe. Geological investigations show that suitable storage sites are present in most European countries. In Denmark initial investigations conducted by the Geological Survey of Denmark and Greenland and private companies indicate that there is significant storage potential at several locations in the subsurface.

Leakage risk assessment of a CO2 storage site: A review

2021 ◽  
pp. 103849
Author(s):  
Raoof Gholami ◽  
Arshad Raza ◽  
Stefan Iglauer
Keyword(s):  
Risk Assessment ◽  
Co2 Storage ◽  
Storage Site

scholarly journals Pore Pressure Analysis for Distinguishing Earthquakes Induced by CO2 Injection from Natural Earthquakes

2020 ◽  
Vol 12 (22) ◽  
pp. 9723
Author(s):  
Chanmaly Chhun ◽  
Takeshi Tsuji
Keyword(s):  
Pore Pressure ◽  
Co2 Storage ◽  
Carbon Capture And Storage ◽  
Co2 Injection ◽  
Storage Site ◽  
Seasonal Fluctuations ◽  
Induced Earthquakes ◽  
Seismogenic Fault ◽  
Seismogenic Faults ◽  
Natural Earthquakes

It is important to distinguish between natural earthquakes and those induced by CO2 injection at carbon capture and storage sites. For example, the 2004 Mw 6.8 Chuetsu earthquake occurred close to the Nagaoka CO2 storage site during gas injection, but we could not quantify whether the earthquake was due to CO2 injection or not. Here, changes in pore pressure during CO2 injection at the Nagaoka site were simulated and compared with estimated natural seasonal fluctuations in pore pressure due to rainfall and snowmelt, as well as estimated pore pressure increases related to remote earthquakes. Changes in pore pressure due to CO2 injection were clearly distinguished from those due to rainfall and snowmelt. The simulated local increase in pore pressure at the seismogenic fault area was much less than the seasonal fluctuations related to precipitation and increases caused by remote earthquakes, and the lateral extent of pore pressure increase was insufficient to influence seismogenic faults. We also demonstrated that pore pressure changes due to distant earthquakes are capable of triggering slip on seismogenic faults. The approach we developed could be used to distinguish natural from injection-induced earthquakes and will be useful for that purpose at other CO2 sequestration sites.

GEOLOGICAL STORAGE OF CARBON DIOXIDE: MODELLING THE EARLY CRETACEOUS SUCCESSION IN THE BARROW SUB-BASIN, NORTHWEST AUSTRALIA

2004 ◽  
Vol 44 (1) ◽  
pp. 653 ◽  
Author(s):  
C.M. Gibson-Poole ◽  
J.E. Streit ◽  
S.C. Lang ◽  
A.L. Hennig ◽  
C.J. Otto
Keyword(s):  
Storage Capacity ◽  
Flow Direction ◽  
Co2 Storage ◽  
Column Height ◽  
Co2 Injection ◽  
Technical Solution ◽  
Exit Point ◽  
Geological Storage ◽  
Migration Pathways ◽  
Northwest Australia

Potential sites for geological storage of CO2 require detailed assessment of storage capacity, containment potential and migration pathways. A possible candidate is the Flag Sandstone of the Barrow Sub-basin, northwest Australia, sealed by the Muderong Shale. The Flag Sandstone consists of a series of stacked, amalgamated, basin floor fan lobes with good lateral interconnectivity. The main reservoir sandstones have high reservoir quality with an average porosity of 21% and an average permeability of about 1,250 mD. The Muderong Shale has excellent seal capacity, with the potential to withhold an average CO2 column height of 750 m. Other containment issues were addressed by in situ stress and fault stability analysis. An average orientation of 095°N for the maximum horizontal stress was estimated. The stress regime is strike-slip at the likely injection depth (below 1,800 m). Most of the major faults in the study area have east-northeast to northeast trends and failure plots indicate that some of these faults may be reactivated if CO2 injection pressures are not monitored closely. Where average fault dips are known, maximum sustainable formation pressures were estimated to be less than 27 MPa at 2 km depth. Hydrodynamic modelling indicated that the pre-production regional formation water flow direction was from the sub-basin margins towards the centre, with an exit point to the southwest. However, this flow direction and rate have been altered by a hydraulic low in the eastern part of the sub-basin due to hydrocarbon production. The integrated site analysis indicates a potential CO2 storage capacity in the order of thousands of Mtonnes. Such capacity for geological storage could provide a technical solution for reducing greenhouse gas emissions.

scholarly journals Alignment of the Safety Assessment Method with New Zealand Legislative Responsibilities

Safety ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 59 ◽  
Author(s):  
Dirk J. Pons
Keyword(s):  
Risk Assessment ◽  
New Zealand ◽  
Systems Engineering ◽  
Health And Safety ◽  
Assessment Method ◽  
Internal Communication ◽  
Assessment Process ◽  
Successful Implementation ◽  
Legislative Framework ◽  
Minor Injuries

Need—National legislative health and safety (H&S) frameworks impose requirements but grant self-management to organisations. Consequently variability arises in management systems, and some organisations struggle to achieve successful implementation. The risk assessment process is key to the H&S management system, and could benefit from greater consistency and better external alignment with the legislative framework of the jurisdiction. Approach—The harm categories in the New Zealand (NZ) Act were adapted into a consequence scale. A non-linear scale was developed for the consequence axis to represent the disproportional nature of catastrophic harm outcomes compared to minor injuries. A hazard assessment process was devised based on systems engineering methods. Organisational decision-criteria were derived from the communications requirement in the Act, and these thresholds linked to expected treatments. Originality—A method is providing for aligning risk assessments with a national legislative framework, and integrating the technical aspects of risk assessment with the management processes. The approach also more explicitly includes recovery actions in contrast to existing methods where prevention dominates. Regarding the management aspects, it shows how thresholds may be defined relative to the legislation, to give clear expectations regarding treatment and internal communication, thereby assisting executives (‘officers’ in terms of the NZ Act) meet their duties.

Integrated Coupled Modelling Study to Assess CO2 Sequestration Potential in a Depleted Gas Field

2021 ◽  
Author(s):  
Ahmad Ismail Azahree ◽  
Farhana Jaafar Azuddin ◽  
Siti Syareena Mohd Ali ◽  
Muhammad Hamzi Yakup ◽  
Mohd Azlan Mustafa ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Co2 Storage ◽  
Coupled Model ◽  
Co2 Injection ◽  
Storage Site ◽  
Coupled Modeling ◽  
Reservoir Properties ◽  
Gas Field ◽  
Sequestration Potential ◽  
Injection Phase

Abstract A depleted gas field is selected as CO2 storage site for future high CO2 content gas field development in Malaysia. The reservoir selected is a carbonate buildup of middle to late Miocene age. This paper describes an integrated modeling approach to evaluate CO2 sequestration potential in depleted carbonate gas reservoir. Integrated dynamic-geochemical and dynamic-geomechanics coupled modeling is required to properly address the risks and uncertainties such as, effect of compaction and subsidence during post-production and injection. The main subsurface uncertainties for assessing the CO2 storage potential are (i) CO2 storage capacity due to higher abandonment pressure (ii) CO2 containment due to geomechanical risks (iii) change in reservoir properties due to reaction of reservoir rock with injected CO2. These uncertainties have been addressed by first building the compositional dynamic model adequately history matched to the production data, and then coupling with geomechanical model and geochemical module during the CO2 injection phase. This is to further study on the trapping mechanisms, caprock integrity, compaction-subsidence implication towards maximum storage capacity and injectivity. The initial standalone dynamic modeling poses few challenges to match the water production in the field due to presence of karsts, extent of a baffle zone between the aquifer and producing zones and uncertainty in the aquifer volume. The overall depletion should be matched, since the field abandonment pressure impacts the CO2 injectivity and storage capacity. A reasonably history matched coupled dynamic-geomechanical model is used as base case for simulating CO2 injection. The dynamic-geomechanical coupling is done with 8 stress steps based on critical pressure changes throughout production and CO2 injection phase. Overburden and reservoir properties has been mapped in Geomechanical grid and was run using two difference constitutive model; Mohr's Coulomb and Modified Cam Clay respectively. The results are then calibrated with real subsidence measurement at platform location. This coupled model has been used to predict the maximum CO2 injection rate of 100 MMscf/d/well and a storage capacity of 1.34 Tscf. The model allows to best design the injection program in terms of well location, target injection zone and surface facilities design. This coupled modeling study is used to mature the field as a viable storage site. The established workflow starting from static model to coupled model to forecasting can be replicated in other similar projects to ensure the subsurface robustness, reduce uncertainty and risk mitigation of the field for CO2 storage site.

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