Constraining fluid migration in low density data area: successful use of integrated modelling in the Southern Perth Basin

2014 ◽  
Vol 54 (2) ◽  
pp. 534
Author(s):  
Laurent Langhi ◽  
Bozkurt Ciftci ◽  
Julian Strand

Constraining trap integrity or CO2 containment potential in areas with low density of data is challenging. We show here how the integration of hard data and modelling improved our understanding of the subsurface tectonic and stratigraphic architecture and ensured an initial definition of hydraulic behaviour of faults and fractures in the onshore Southern Perth Basin. A first-order geomodel was built based on interpretation of low-density 2D-seismic data and constrained by well, geophysical, and outcrop data. Forward stratigraphic models were deformed and implemented in the geomodel to predict the distribution of the phyllosilicate content. Membrane fault-seal prediction was performed based on the Shale Gouge Ratio algorithm to estimate the lateral migration potential. Characterisation of the stress state of fault planes was used to define the likelihood of reactivation and to predict vertical migration and caprock bypass. The elastic dislocation method was used to model the density and mode of failure of subsidiary sub-seismic faults that can impact on the caprock integrity. This was also used to constrain and validate the structural model. The integrated modelling significantly decreased uncertainties on the subsurface architecture and ensured the first-order definition of the CO2 migration and containment potential for the Wonnerup reservoir in the SW Hub. The maximum CO2 column heights supported by faults and potential leak points were estimated and migration scenarios and risks were defined.

Author(s):  
Flemming G. Christiansen ◽  
Jørgen A. Bojesen-Koefoed ◽  
Gregers Dam ◽  
Troels Laier ◽  
Sara Salehi

The Nuussuaq Basin in West Greenland has an obvious exploration potential. Most of the critical elements are well documented, including structures that could form traps, reservoir rocks, seals and oil and gas seepage that documents petroleum generation. And yet, we still lack a full understanding of the petroleum systems, especially the distribution of mature source rocks in the subsurface and the vertical and lateral migration of petroleum into traps. A recently proposed anticlinal structural model could be very interesting for exploration if evidence of source rocks and migration pathways can be found. In this paper, we review all existing, mostly unpublished, data on gas observations from Nuussuaq. Furthermore, we present new oil and gas seepage data from the vicinity of the anticline. Occurrence of gas within a few kilometres on both sides of the mapped anticline has a strong thermogenic fingerprint, suggesting an origin from oil-prone source rocks with a relatively low thermal maturity. Petroleum was extracted from an oil-stained hyaloclastite sample collected in the Aaffarsuaq valley in 2019, close to the anticline. Biomarker analyses revealed the oil to be a variety of the previously characterised “Niaqornaarsuk type,” reported to be formed from Campanian-age source rocks. Our new analysis places the “Niaqornaarsuk type” 10 km from previously documented occurrences and further supports the existence of Campanian age deposits developed in source rock facies in the region.


Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 348
Author(s):  
Merced Montesinos ◽  
Diego Gonzalez ◽  
Rodrigo Romero ◽  
Mariano Celada

We report off-shell Noether currents obtained from off-shell Noether potentials for first-order general relativity described by n-dimensional Palatini and Holst Lagrangians including the cosmological constant. These off-shell currents and potentials are achieved by using the corresponding Lagrangian and the off-shell Noether identities satisfied by diffeomorphisms generated by arbitrary vector fields, local SO(n) or SO(n−1,1) transformations, ‘improved diffeomorphisms’, and the ‘generalization of local translations’ of the orthonormal frame and the connection. A remarkable aspect of our approach is that we do not use Noether’s theorem in its direct form. By construction, the currents are off-shell conserved and lead naturally to the definition of off-shell Noether charges. We also study what we call the ‘half off-shell’ case for both Palatini and Holst Lagrangians. In particular, we find that the resulting diffeomorphism and local SO(3,1) or SO(4) off-shell Noether currents and potentials for the Holst Lagrangian generically depend on the Immirzi parameter, which holds even in the ‘half off-shell’ and on-shell cases. We also study Killing vector fields in the ‘half off-shell’ and on-shell cases. The current theoretical framework is illustrated for the ‘half off-shell’ case in static spherically symmetric and Friedmann–Lemaitre–Robertson–Walker spacetimes in four dimensions.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Clifford V. Johnson ◽  
Felipe Rosso

Abstract Recent work has shown that certain deformations of the scalar potential in Jackiw-Teitelboim gravity can be written as double-scaled matrix models. However, some of the deformations exhibit an apparent breakdown of unitarity in the form of a negative spectral density at disc order. We show here that the source of the problem is the presence of a multi-valued solution of the leading order matrix model string equation. While for a class of deformations we fix the problem by identifying a first order phase transition, for others we show that the theory is both perturbatively and non-perturbatively inconsistent. Aspects of the phase structure of the deformations are mapped out, using methods known to supply a non-perturbative definition of undeformed JT gravity. Some features are in qualitative agreement with a semi-classical analysis of the phase structure of two-dimensional black holes in these deformed theories.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrícia Moura e Sá ◽  
Catarina Frade ◽  
Fernanda Jesus ◽  
Mónica Lopes ◽  
Teresa Maneca Lima ◽  
...  

PurposeWicked problems require collaborative innovation approaches. Understanding the problem from the users' perspective is essential. Based on a complex and ill-defined case, the purpose of the current paper is to identify some critical success factors in defining the “right problem” to be addressed.Design/methodology/approachAn empirical research study was carried out in a low-density municipality (case study). Extensive data were collected from official databases, individual semi-structured interviews and a focus group involving citizens, local authorities, civil servants and other relevant stakeholders.FindingsAs defined by the central government, the problem to be addressed by the research team was to identify which justice services should be made available locally to a small- and low-density community. The problem was initially formulated using top-down reasoning. In-depth contact with citizens and key local players revealed that the lack of justice services was not “the issue” for that community. Mobility constraints and the shortage of economic opportunities had a considerable impact on the lack of demand for justice services. By using a bottom-up perspective, it was possible to reframe the problem to be addressed and suggest a new concept to be tested at later stages.Social implicationsThe approach followed called attention to the importance of listening to citizens and local organisations with a profound knowledge of the territory to effectively identify and circumscribe a local problem in the justice field.Originality/valueThe paper highlights the limitations of traditional rational problem-solving approaches and contributes to expanding the voice-of-the-customer principle showing how it can lead to a substantially new definition of the problem to be addressed.


2019 ◽  
Vol 29 (8) ◽  
pp. 1311-1344 ◽  
Author(s):  
Lauri T Hella ◽  
Miikka S Vilander

Abstract We propose a new version of formula size game for modal logic. The game characterizes the equivalence of pointed Kripke models up to formulas of given numbers of modal operators and binary connectives. Our game is similar to the well-known Adler–Immerman game. However, due to a crucial difference in the definition of positions of the game, its winning condition is simpler, and the second player does not have a trivial optimal strategy. Thus, unlike the Adler–Immerman game, our game is a genuine two-person game. We illustrate the use of the game by proving a non-elementary succinctness gap between bisimulation invariant first-order logic $\textrm{FO}$ and (basic) modal logic $\textrm{ML}$. We also present a version of the game for the modal $\mu $-calculus $\textrm{L}_\mu $ and show that $\textrm{FO}$ is also non-elementarily more succinct than $\textrm{L}_\mu $.


2012 ◽  
Vol 46 (1) ◽  
pp. 139-153 ◽  
Author(s):  
EMILIA MARÍA DURÁN-ALMARZA

The Dominican American community in New York is perhaps one of the best examples of how processes of transculturation are affecting traditional definitions of ethnic identification. Given the intense economic, social and cultural transnational exchanges between the island and the USA from the 1960s, Dominicanyorks have been challenging the illusion of homogeneity in the definition of Americanness for decades, creating transnational social networks that transcend traditional national and ethnographic boundaries. The theatrical works of Josefina Báez, a Dominican American performer living in New York, and Sherezada (Chiqui) Vicioso, a Dominican poet and playwright who lived and worked in the US metropolis for decades before moving back to the Dominican Republic, lyrically explore issues of diaspora, identity and migration and the impact these phenomena might have in the lives of migrant Dominican women. Presenting diasporic experiences from two differing but interconnected locales – New York and the Dominican Republic – these plays offer two complementary views on the ways in which ethnicity, race, social class, age and geopolitical location interact in the formation of transcultural identities, thus contributing to develop a hemispheric approach to the study of identity formation in the Americas.


2015 ◽  
Vol 29 (20) ◽  
pp. 1550109 ◽  
Author(s):  
Desmond A. Johnston ◽  
Marco Mueller ◽  
Wolfhard Janke

The purely plaquette 3D Ising Hamiltonian with the spins living at the vertices of a cubic lattice displays several interesting features. The symmetries of the model lead to a macroscopic degeneracy of the low-temperature phase and prevent the definition of a standard magnetic order parameter. Consideration of the strongly anisotropic limit of the model suggests that a layered, “fuki-nuke” order still exists and we confirm this with multi-canonical simulations. The macroscopic degeneracy of the low-temperature phase also changes the finite-size scaling corrections at the first-order transition in the model and we see this must be taken into account when analyzing our measurements.


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