1,721,037 research outputs found
Fluid-rock interactions and their implications on carbonate reservoir characterization
Full text linkThe objective of my research has been to define the interactions between fluid and rock properties at different environmental conditions and observation scale to reduce the uncertainty in the carbonate reservoir characterization.
Here, I integrate field observations, subsurface data, petrophysical and frictional laboratory measurements focusing on carbonate-bearing rocks to better constrain factors controlling fluid-rock interactions with applications to active petroleum systems. In particular, I focus on the Burano-Bolognano carbonate petroleum system that extends from the northern sector of the Majella mountain to the Cigno/Vallecupa oil fields, in Abruzzo Region (Central Italy).
This area is of particular interest because of the following reasons:
It has received great attention by oil companies in the past for its structural, stratigraphic, and geodynamic evolution, which led it to be an important target for hydrocarbon exploration during the past century. For this reason, it is characterized by a public dense dataset of wells, reports, maps, etc.
It allows to study all petroleum system elements (with the exception of the source rock), such as: reservoir, seal, traps, and migration pathways at field scale.
It allows to understand the influence of subsurface fluids on the petrophysical properties of carbonate reservoir rocks since the outcropping portions of reservoir interval are both clean and hydrocarbon-saturated. This allows measuring and comparing the variations of petrophysical properties between hydrocarbon-bearing and hydrocarbon-free samples.
It is regarded as an analogue of a faulted and fractured reservoir for other carbonate petroleum systems worldwide and in particular in the Adriatic area.
The results of my research quantify the influence of fluid properties in changing of the petrophysical and frictional properties of the bearing-carbonate rocks. The presence of viscous fluids, such as heavy hydrocarbons, at ambient temperature defines an increase of the wave velocities respect to those of the unsaturated samples and determines a possible strengthening and stiffening of the reservoir rock. With increasing temperature, distinct downward trends are recorded, especially for the P-wave velocities. Moreover, the presence of fluids along faults promotes a slow slip behaviour, which was more marked with the presence of clay minerals along fault surface.
Finally, starting from these results, I simulate the evolution of the Burano-Bolognano petroleum system and the related fluids movements, inferring that within this petroleum system the vertically hydrocarbon migration is driven by fractures/faults and the subsequently lateral migration determinates a gradual oil biodegradation with an increase of its density
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Trattamento combinato videolaparoscopico ed endoscopico (Rendez Vous) della calcolosi colecisto-coledocica
No full textStructural and thermochronological constraints to the evolution of the West Antarctic Rift System in central Victoria Land
No full textUncertainty still persists on the structure and evolution of the West Antarctic Rift System, which is one of the largest extensional provinces on Earth. In this paper, we present results of a combined structural and apatite fission track study of the western shoulder of the rift system, in the western coastal area of the Ross Sea between the Reeves and the Mawson glaciers. Structural data indicate that the onshore fault pattern is dominated by N–S striking right-lateral strike-slip to transtensional fault systems and their related subsidiary fault populations in the damage zones. Thermochronological data support a Cenozoic age for these faults and, in particular, the onset of the oblique rifting event at about 50 Ma, in Eocene times. Apatite fission track analyses also suggest the possible occurrence of an older cooling/exhumation event in Cretaceous times. When integrated with the geological and geophysical data sets available in the literature, our structural and thermochronological data provide further support to the interpretation of Cenozoic oblique rifting in the West Antarctic Rift System as induced by the transfer of dextral shear from the mid oceanic ridge in the Southern Ocean, into the Antarctic Plate interior
Laparoscopic repair of strangulated hernias
No full textBackground: Although laparoscopic transabdominal preperitoneal polypropylene (TAPP) hernia repair is now a recognized procedure for groin hernia repair in patients undergoing elective surgery, there is a scarcity of data on TAPP repair in emergency situations such as those involving strangulated hernias. Methods: Unless contraindicated, the authors' department considers laparoscopic TAPP repair the procedure of choice for all strangulated hernias. A prospective database of 1,532 consecutive hernia repairs performed between May 1998 and April 2004 was reviewed. Results: A total of 28 irreducible strangulated hernias were observed and repaired through laparoscopic TAPP. There were three conversions (10.7%): one because of extensive adhesions and two because of bowel distention. Resection became necessary in 9 (36%) of the 25 cases involving effective TAPP repair of strangulated hernias. The mean operation time, with and without resection, was 103 and 55 min, respectively. The rate of postoperative morbidity was 4% because of one inguinal hematoma case. During a mean follow-up period of 340 days, there were no recurrences after TAPP repair. Conclusions: For selected patients, the TAPP approach appears to be a good therapeutic option for strangulated hernias
La scelta dell'appendicectomia videolaparoscopica come primo momento chirurgico nella didattica mininvasiva dello specializzando in chirurgia generale : risultati
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