1,721,036 research outputs found
Morphology and carbohydrate accumulation in Pelargonium cuttings as affected by blue ratio of the supplemental lighting on stock plants
Full text linkThis study evaluated the influence of supplemental top LED lighting on stock plants of Pelargonium × hortorum ‘Ice Crystal’, with 3 R:B rates (H = 73% R + 23% B + 4% FR; M = 63% R + 33% B + 4% FR and L = 53% R + 43% B + 4% FR), on morphology, soluble carbohydrate and starch content of cuttings, in comparison with the natural lighting (NL). All LED lamps supplied the same PPFD at bench level (100±20 μmol m-2 s-1) for 14 h day-1. The growing period (November-January) was characterized by 9.5-10 natural light hours per day and a DLI ranging from 1.1 to 2.5 mol m-2 d-1 at bench level (NL). Supplemental lighting, regardless of the blue rate, reduced petiole length (-22.9%) and canopy diameter (- 16.0%) of stock plants but did not affected significantly their branching (3.7 stems plant-1) and leaf area (2352.4 cm2), compared to NL. Meanwhile, plants under lighting exhibited a double dry weight (+ 107.4%) mainly due to stem dry weight increase (+ 99.4%). Cuttings severed from plants under lighting were characterized by a lower leaf dry weight (-34.3%) and a smaller leaf area (-31.7% under M and L) than those grown under NL, despite of the higher leaf number (8.7 vs. 6.7). Moreover, supplemental lighting, increased carbohydrates concentrations in leaves, from 4.0 up to 10.7 mg g-1 dw and from 4.4 up to 110.4 mg g-1 dw with low blue ratio, for glucose and starch, respectively. At the same time lighting enhanced starch accumulation in stem, from 29.7 in NL up to 230 mg g-1 dw in H light, but halved glucose, indeed its concentration decreased from 6.7 to 3.0 mg g-1 DW under NL and lighting, respectively, without differences among spectra. Blue ratio in LED lamps should not exceed 23% for avoiding leaf damages (e.g., yellow and necrotic lamina) and promoting the production of cuttings with the highest quality
Permeability anisotropy of fractured and faulted tight Cretaceous platform carbonates by use of 3D fracture modelling (Agri Valley, southern Italy)
No full textIn the Agri Valley, high-angle faults crosscut platform carbonates that are analogues of the lithological units that host the deep seated largest onshore oil reservoir in Europe. The main faults are W-NW oriented with a left-lateral strike-slip kinematic; additionally, three sets of related secondary faults are present: (i) N-NE oriented with right-lateral/transtensional kinematics, (ii) E-W trending left-lateral transtensional and (iii) N-NW trending left-lateral transpressional. Two of the secondary N-NE striking faults, strike-slip and transtensional, together with the adjacent host rock, were selected to build a Discrete Fracture Network model eventually used to evaluate the hydraulic properties and permeability anisotropy of these faults. The outcomes of this modelling show that the total permeability of the fault zones is higher than that one of the host rock. Moreover, the results are consistent with the transtensional fault having higher permeability values relative to the strike-slip one. The permeability anisotropy within the fault damage zone as well as in the host rock is mainly related to the fracture orientation
Development and distribution of bed-parallel compaction bands and pressure solution seams in carbonates (Bolognano Formation, Majella Mountain, Italy)
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Shearing of syn-sedimentary carbonate breccia along strike-slip faults, Altamura Fm., Southern Italy
No full textSpatial and dimensional variations of the faults and fractures attributes, and their influence on the permeability of the Cretaceous platform carbonates in Val d'Agri, southern Italy
No full textIn the Agri Valley, high-angle faults crosscut platform carbonates that are analogues of the lithological units that host the deep-seated Val d’Agri field, which is among the largest onshore oil reservoirs in Western Europe. The main faults are W-NW oriented with a left-lateral strike-slip kinematic; additionally, three sets of related secondary faults are present: (i) N-NE oriented with right-lateral/transtensional kinematics, (ii) E-W trending left-lateral transtensional and (iii) N-NW trending left-lateral transpressional. Two of the secondary N-NE striking faults, strike-slip and transtensional, together with the adjacent host rock, were selected to build a Discrete Fracture Network model eventually used to evaluate the hydraulic properties and permeability anisotropy of these faults. The outcomes of this modelling show that the total permeability of the fault zones is higher than that one of the host rock. Moreover, the results are consistent with the transtensional fault having higher permeability values relative to the strike-slip one. The permeability anisotropy within the fault damage zone as well as in the host rock is mainly related to the fracture orientation
Fault zone properties in carbonate rocks: insights for well logs, core and field data
No full textIn the last few years, numerous works addressed the deformation processes in carbonate rocks. These studies,
generally sponsored by the oil industry, aimed to a better understanding of the structural and hydraulic properties
of fault zones as well as of the subsurface fluid pathways in deformed carbonate rocks. This effort was mainly
driven by the economic significance that carbonate rocks have for the oil industry, since they represent important
natural reservoirs of hydrocarbons. According to the many field-based research scientific articles published in
the recent past, both structural and hydraulic properties of fault zones, and their evolution trough time, exert a
first order control on subsurface fluid flow and accumulation in fractured carbonate reservoirs. In order to convert
this knowledge into predictive modeling tools that would help to optimize their exploitation, it should be useful
to integrate the field-based data together with the subsurface data, which generally consist of core and well log
(resistivity, acoustic, gamma ray etc.) analyses usually gathered to assess the formation evaluation of carbonate
reservoir.
The presented work aims at filling this cognitive gap by the acquisition and elaboration of subsurface geophysical
properties of a hydrocarbon-bearing oblique normal fault zone characterized by 10’s of m offset, and cropping out
in an exposed analogue of fractured carbonate reservoir (Maiella Mountain, Italy). The deformation mechanisms
associated to the processes of fault nucleation and development within the Oligo-Miocene shallow-water carbonate
rocks were documented in the recent past by our research group. In this present contribution, we present the
results of our elaboration of the geophysical data, obtained from well logs oriented perpendicular to the study fault
zone. These results are consistent with the following statements: a) there is a meaningful correlations between
cores and digital images; b) a detailed structural analysis of the deformed carbonates can be performed by using
well cores and digital image data; c) both matrix (primary) and fracture (secondary) porosities can be obtained
from subsurface data; d) some possible relationships exist between secondary porosity and the measured log
geophysical properties (P- and S-wave velocities, Resistivity). In conclusion, the results of this multi-disciplinary
study, which involved the analyses of well logs, core and outcrop data of an hydrocarbon-bearing fault zone
permitted us, therefore, to obtain useful correlation between fracture porosity and geophysical properties. We
propose some practical solutions to compute the petrophysical parameters in order to assess both primary and
secondary porosity in fractured carbonate reservoirs
From fractures to flow: A field-based quantitative analysis of an outcropping carbonate reservoir
No full textFractures can play an important role in the fluid storage –migration properties of fault damage zones. In this present contribution, we document the role exerted by fractures on fluid flow in carbonate damage zones of hydrocarbon-bearing, km-long, oblique-slip normal faults with 10's of m-throw. The carbonate fault damage zones were analysed by mean of scan line surveys conducted in both tar-free and tar-rich outcrops. In this way, the relationships among the individ ual fracture characteristics (length, spacing, aperture, orientation,
connectivity and distance from slip surfaces pertaining to small faults of the fault damage zones) and hydrocarbons have been established. Data obtained by scan line surveys were also used to compute the
amount of fracture porosity, the degree of fracture connectivity and, based upon simple assumptions, the orientation of the local σhmax at times of faulting. Additionally, scan line surveys were also carried out along outcrops exposing unfaulted carbonate host rocks. The results of our computation are consistent with a carbonate host rock made up of a quite isotropic fracture array comprised of isolated and coupled fractures, in which individual fracture sets have negative exponential spacing distributions. In terms of fluid fl ow, the
fracture array of the carbonate host rock enhances the fluid storage. Conversely, the fracture array of the fault damage zones is characterized by a pronounced anisotropy due to interconnected fractures, which enhance the fluid migration. Fractures in the fault damage zones include those inherited from background
deformation and others related to the faulting processes. The latter fracture sets are characterized by power law spacing distributions. In conclusion, counter-intuitively, both fracture length and fracture spacing do not have any correlation with hydrocarbons in the fault damage zones. On the contrary, fracture anisotropy, fracture spread and fracture orientation are positively correlated with hydrocarbons
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