940 research outputs found
Carbon capture and storage in compressional basins: global to reservoir-scale assessments and integrated case study of the Puig-reig anticline (SE Pyrenees)
[eng] Carbon capture and storage (CCS) has been proposed as a potential technology to mitigate climate change. However, there is currently a huge gap between the global CCS deployment and that which will be ultimately required. To date, CCS deployment has been restricted to the most favourable tectonic settings, such as extensional passive margin and post-rift basins and compressional foreland basins. In addition, CCS deployment has stalled in most countries, with only limited commercial projects realised mainly in hydrocarbon-rich countries for enhanced oil recovery. This Ph.D. thesis aims to assess the potential of CCS development in compressional basins and hydrocarbon-limited regions at different scales: from a global-scale assessment to a national-scale assessment in Spain and finally, to a reservoir-scale analogue case study, focusing on the Puig-reig anticline (SE Pyrenees).
Compressional settings host some of the most significant oil and gas resources in the world and will be key to the large-scale deployment of CCS. On the global scale, we present an integrated source-to-sink analysis tool that combines basin distribution, hydrocarbon resources and CO2 emissions to assess the potential of compressional basins for CCS development. This methodology allows identifying five high-priority regions for prospective CCS development in compressional basins: North America, north-western South America, south-eastern Europe, the western Middle East and western China. The results indicate that compressional basins will have to play a critical role in the future of CCS if this technology is to be implemented worldwide.
Instead of developing CCS via CO2 enhanced oil recovery (CO2-EOR), hydrocarbon-limited countries need to devise alternative strategies if they intend to implement CCS in their decarbonisation strategies. On the national scale, we present a novel systematic source-to-sink assessment methodology based on a hubs and clusters approach to identify favourable regions for CCS deployment in hydrocarbon-limited countries. Throughout the evaluation of the Spanish case study, we identify 15 emission hubs from the power and the hard-to-abate sectors and priority source- to-sink clusters, based on screening and ranking processes using a multi-criteria decision-making method. North-Western and North-Eastern Spain are recognised as priority regions due to resilience provided by different types of CO2 sources and multiple geological storage structures. CCS, especially in the hard-to-abate sector, and in combination with other low-carbon energies, remains a significant contributor to the Paris Agreement’s mid-century net-zero target. This methodology can attract renewed public and political interest in viable deployment pathways of CCS in hydrocarbon-limited
countries.
The Ebro Foreland Basin, identified as one of the most potential areas for CCS development in Spain, is a typical hydrocarbon-limited compressional basin with low availability of geological and geophysical data required for the suitability assessment for CO2 storage. In this work, we carry out an integrated study of the Puig-reig anticline (SE Pyrenees) to be used as an outcrop analogue to explore the reservoir potential of foreland basin margin sedimentary systems. This anticline exposes continuous outcrops deposited in a proximal to medial fluvial fan system with an overall southeast downstream trend. The proximal deposits, mainly spreading in the northwest portion of the anticline, are characterised by conglomerates with minor interbedded sandstones. These are interpreted as having been deposited from unconfined flash floods and wide-shallow channel streams. The medial deposits, covering the rest of the anticline, consist of interbedded beds of conglomerates, sandstones and claystones, deposited in braided channel streams and overbanks.
In order to understand the fracture distribution in the Puig-reig anticline and how it can potentially affect reservoir potential, fracture networks have been characterised using the linear scanline method, and four fracture sets (F1 to F4) have been identified in the target structure. The north limb shows low fracture intensity but large fracture length and aperture. The crest and the crest-limb transition zones present relatively high fracture intensity and variable fracture length and aperture. The south limb has low fracture intensity and small fracture length and aperture. Based on multiple linear regression analysis, we observe that fracture intensity is mainly controlled by the structural position, bedding thickness and lithological associations, with more intense fracturing in thin sandstone layers with multiple interlayers of fine deposits in the high strain zones. The fracture length mainly depends on bedding thickness and is affected by lithological associations. The fracture apertures are mainly controlled by lithofacies.
An integrated analysis of structural, petrological and geochemical characteristics allows identifying five generations of calcite cements (Cc0 to Cc4) and fluid regimes in the Puig-reig anticline. Before intensive deformation, Cc0 precipitated in intergranular porosity from meteoric fluids in the phreatic zone. During the most intense phase of thrusting and folding, Cc1 precipitated in intergranular porosity, faults and F1 to F4 fracture sets from hydrothermal fluids migrated from the deep areas of the SE Pyrenees. During the late stage of fold growth, Cc2 mainly precipitated in normal and strike- slip faults in the anticline crest from the mixing between hydrothermal and meteoric fluids during the crestal collapse, or from hydrothermal fluids with shallower burial depth compared to that of Cc1.
Cc3 mainly precipitated in faults and F1 and F4 fracture sets in the north-western zone of the anticline from formation fluids probably migrated through the frontal thrusts. During the continuous denudation, Cc4 precipitated in the reopened F1 to F4 fracture sets from meteoric fluids.
The comparison of the Puig-reig anticline with other similar depositional and tectonic settings worldwide allows exploring the reservoir potential for CO2 storage at foreland basin margins. In the Puig-reig anticline, the proximal to medial deposits present low porosity of host rocks due to the prevailing presence of calcite cement, with limited high porosity concentrated in massive medium and coarse lithofacies in the medial fluvial fan. Sandstone lithofacies deposited from the medial fluvial fan and located in the high strain zones feature relatively high fracture intensity, which have relative high potential to be effective reservoirs. The study conducted in the Puig-reig anticline provides a conceptual model useful to understand the reservoir characteristics at the basin margins. According to this model, the reservoir potential is comprehensively controlled by sedimentology, diagenesis and deformation. The effective combination of both structure and facies can make basin margin locations potential areas for effective reservoirs, even in the presence of overall low porosity. Future work will focus on building a static reservoir model of the Puig-reig anticline based on the results obtained in the sedimentology, fracture and diagenesis studies, and finally carrying out fluid flow simulations to determine the main controls on CO2 injection and storage in such a geological setting.[cat] La captura i emmagatzematge de carboni (CCS) s’ha proposat com una tecnologia potencial per mitigar el canvi climĂ tic. No obstant això, actualment hi ha una enorme bretxa entre el desplegament global de CCS i el que finalment serĂ necessari. Fins ara, el desplegament de CCS s’ha restringit a les configuracions tectòniques mĂ©s favorables, com ara marges passius extensius, conques post-rift i conques d’avantpaĂs compressives. A mĂ©s, el desplegament de CCS s’ha estancat a la majoria de paĂŻsos, amb pocs projectes comercials realitzats principalment a paĂŻsos rics en hidrocarburs per millorar la recuperaciĂł del petroli. Aquesta tesi doctoral tĂ© com a objectiu avaluar el potencial de desenvolupament de CCS en conques de compressiĂł i regions sense hidrocarburs a diferents escales: des d’una avaluaciĂł a escala mundial fins a una avaluaciĂł a escala nacional a Espanya i, finalment, a l’estudi d’un analeg a escala de dipòsit, l’anticlinal de Puig-reig (SE Pirineus).
Els entorns compressius contenen alguns dels reservoris de petroli i gas mĂ©s importants del mĂłn i seran claus per al desplegament a gran escala de CCS. A escala mundial, presentem una eina d’anĂ lisi integrada que combina la distribuciĂł de la conca, els recursos d’hidrocarburs i les emissions de CO2 per avaluar el potencial de les conques compressives per al desenvolupament de CCS. Aquesta metodologia ens ha permès identificar cinc regions d’alta prioritat per al desenvolupament potencial de CCS a les conques compressives: Amèrica del Nord, nord-oest d’Amèrica del Sud, sud-est d’Europa, l’Oest de l’Orient MitjĂ i l’oest de la Xina. Els resultats indiquen que les conques compressives hauran de tenir un paper crĂtic en el futur de la CCS si aquesta tecnologia s’implementa a tot el mĂłn.
En lloc de desenvolupar CCS mitjançant la recuperaciĂł del petroli (CO2-EOR), els paĂŻsos que tenen pocs hidrocarburs han d’elaborar estratègies alternatives si tenen la intenciĂł d’implementar CCS en les seves estratègies de descarbonitzaciĂł. A escala nacional, presentem una nova metodologia sistemĂ tica d’avaluaciĂł basada en “centres i clĂşsters” per identificar les regions favorables al desplegament de CCS als paĂŻsos amb pocs hidrocarburs. Aquesta eina l’hem aplicat en un cas de l’estat espanyol, on identifiquem 15 centres d’emissions en sectors de producciĂł d’energia i d’indĂşstries difĂcils d’abatre i s’han dissenyat els clĂşsters prioritaris de font-embornal, basats en processos de selecciĂł i classificaciĂł mitjançant un mètode de presa de decisions multicriteri. El nord- oest i el nord-est d’Espanya s’han identificat com les regions prioritĂ ries degut a la resiliència que els hi proporciona diferents tipus de fonts de CO2 i mĂşltiples estructures d’emmagatzematge geològic. El CCS, especialment per descarbonitzar el sector difĂcil de reduir, i en combinaciĂł amb altres
energies de baixes emissions en carboni, continua sent un contribuent significatiu a l’objectiu de emissions zero netes per mitjans d’aquest segle segons l’Acord de ParĂs. Aquesta metodologia que presentem pot atreure un interès pĂşblic i polĂtic renovat sobre aquesta tecnologia, en especial en els paĂŻsos amb pocs hidrocarburs.
La conca d’avantpaĂs de l'Ebre, identificada com una de les Ă rees potencials per al desenvolupament de CCS a Espanya, Ă©s una conca compressiva tĂpica amb poc interès pels hidrocarburs i, per tant, amb baixa disponibilitat de dades geològiques i geofĂsiques necessĂ ries per a l'avaluaciĂł de la idoneĂŻtat per a l'emmagatzematge de CO2. En aquest treball, realitzem un estudi integrat de l’anticlinal de Puig-reig (SE Pirineus) per utilitzar-lo com un anĂ leg en superfĂcie per explorar el potencial de les conques sedimentaries d’avantpaĂs per l’emmagatzemament de CO2. Aquest anticlinal exposa afloraments continus dipositats en un sistema de ventalls fluvials proximals a intermedis amb una tendència general descendent cap el sud-est. Els dipòsits proximals, que s’estenen principalment a la part nord-oest de l’anticlinal, es caracteritzen per conglomerats amb gresos intercalats. S’interpreta com si s’haguessin dipositat a partir d’inundacions instantĂ nies no confinades i canals amples i de poca fondĂ ria. Els dipòsits de la zona intermèdia, que cobreixen la resta de l’anticlinal, consisteixen en capes interestratificades de conglomerats, gresos i argiles, dipositats en canals trenats i sobreeiximent dels canals.
Per tal d’entendre la distribuciĂł de les fractures a l’anticlinal de Puig-reig i com aquestes poden afectar el potencial del reservori d’aquesta estructura, s’han caracteritzat les xarxes de fractures mitjançant el mètode de la lĂnia d’escaneig lineal i s’han identificat quatre conjunts de fractures (F1 a F4). L'extrem nord de l’anticlinal presenta una intensitat de fractures baixa, però una gran longitud i obertura de les fractures. La cresta i les zones de transiciĂł entre la cresta i els flancs presenten una intensitat de fractures relativament alta i una longitud i una obertura de les fractures variables. L’extrem sud tĂ© una intensitat de fractures baixa i una longitud i una obertura de les fractures petites. Basat en l’anĂ lisi de regressiĂł lineal mĂşltiple, observem que la intensitat de la fractura estĂ controlada principalment per la posiciĂł estructural, el gruix de les capes i les associacions litològiques, amb una fracturaciĂł mĂ©s intensa en les capes fines de arenites amb mĂşltiples capes de dipòsits fins a les zones de mĂ©s deformaciĂł de l’anticlinal. La longitud de la fractura depèn principalment del gruix de les capes i es veu afectada per les associacions litològiques. Les obertures de les fractures estan controlades principalment per les litofĂ cies.
Una anĂ lisi integrada de les caracterĂstiques estructurals, petrològiques i geoquĂmiques permet identificar cinc generacions de ciments de calcita (Cc0 a Cc4) i de règim de fluids a l’anticlinal de
Puig-reig. Abans de la deformaciĂł intensiva, Cc0 precipitava en la porositat intergranular a partir de fluids meteòrics a la zona freĂ tica. Durant la fase mĂ©s intensa d’encavalcament i plegament, Cc1 va precipitar en porositat intergranular, falles i en els conjunts de fractures de F1 a F4 a partir de fluids calents migrats des de les zones profundes. Durant la fase tardana del creixement del plec, el Cc2 precipitĂ principalment en falles normals i direccionals en la cresta de l´anticlinal a partir de la barreja entre fluids calents i meteòrics durant el col·lapse de la cresta o bĂ© a partir de fluids calents però a una profunditat d’enterrament inferior a la de Cc1. Cc3 precipitĂ principalment en falles i en els conjunts de fractures F1 i F4 a la zona nord-oest de l’anticlinal a partir de fluids de formaciĂł que probablement van migrar a travĂ©s dels encavalcaments frontals. Durant la denudaciĂł contĂnua, Cc4 va precipitar en els conjunts de fractures reoberts de F1 a F4 a partir de fluids meteòrics.
La comparaciĂł de l’anticlinal de Puig-reig amb altres zones del mon amb ambients deposicional i tectònics similars permet explorar el potencial de d’emmagatzematge de CO2 d’aquest tipus d’estructures en conques d’avantpaĂs. A l’anticlinal de Puig-reig, els dipòsits proximals a intermedis presenten una porositat baixa de les roques hostes a causa de la presència predominant de ciment de calcita, amb algunes zones de porositat mĂ©s elevada concentrades en litofĂ cies massives de gra mig a groller de les zones intermèdies del ventall fluvial. Les litofĂ cies d’arenites dipositades en la zona intermèdia del ventall i situades a les zones major deformaciĂł presenten una intensitat de fractura relativament elevada, amb un potencial relativament elevat per ser dipòsits efectius. L’estudi realitzat a l’anticlinal de Puig-reig proporciona un model conceptual Ăştil per entendre les caracterĂstiques dels reservoris en els marges d’una conca. Segons aquest model, el potencial del reservori estĂ controlat de manera exhaustiva per la sedimentologia, la diagènesi i la deformaciĂł. La combinaciĂł efectiva tant de l’estructura com de la fĂ cies pot fer de les zones del marge de la conca que siguin zones potencials com reservoris efectius, fins i tot en presència d’una porositat baixa. Els treballs futurs es centraran en la construcciĂł d’un model estĂ tic del dipòsit de l’anticlinal de Puig-reig basat en els resultats obtinguts en els estudis de sedimentologia, fractures i diagènesi i, finalment, la realitzaciĂł de simulacions de flux de fluids per determinar els principals controls d’injecciĂł i emmagatzematge de CO2 en aquests tipus de sistemes geològics sedimentaris
The Development Countermeasures of Industry Clusters in Northeast China
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Radical-Enhanced Chinese Character Embedding
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processing algorithms typically regard word or character as the basic unit but
ignore the crucial radical information. In this paper, we fill this gap by
leveraging radical for learning continuous representation of Chinese character.
We develop a dedicated neural architecture to effectively learn character
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