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Madrid, Spain

Rarely has a technique related to asphalt mixes given rise to such interest in recent years as Low Temperature Mixing. The main reason is the growing awareness of the need for all industries to comply with the Kyoto protocol for emission reduction. The problem of climate change at a global level, CO 2 emissions and the rise of alternative energies as a response to a possible reduction in fossil fuel reserves, have all meant that agents involved in different aspects of the construction and maintenance of roads are now taking measures to ensure that the industry has as little negative impact as possible on the environment, while at the same time reducing energy consumption. This awareness has led manufacturers of asphalt mixes, the authorities responsible for roads and manufacturers of hydrocarbon binders to recommend and perfect a number of products and manufacturing techniques that allow work on asphalt mixes at lower than conventional temperatures which were unthinkable a few years ago. This paper outlines a few of these methods. Some of them are very old but once more becoming fashionable, such as techniques using bituminous emulsion for cold and warm mixes, or half warm mixes with bitumen that are made either by the use of additives or by modifying the manufacturing processes to achieve indirect foaming. Using zeolites is another way of working at lower than normal temperatures, as it produces foaming during the mixing process. The importance of these techniques can be seen from the interest they aroused at the latest Eurobitume congress, where a whole day was devoted to these technologies. Source

Garcia-Carballido C.,Maersk Oil | Garcia-Carballido C.,CEPSA Inc | Styles A.,Task Geoscience Ltd. | Poppelreiter M.,Royal Dutch Shell
AAPG Memoir

Copyright © 2010 by The American Association of Petroleum Geologists. Poor seismic imaging in the vicinity of salt domes is a well-known problem in major hydrocarbon basins such as the Gulf of Mexico and the North Sea. The consequence of poor imaging is volumetric and well targeting uncertainty. Structural interpretation of dipmeter and image logs is an essential technique to locally calibrate seismic maps and capture gross rock volume uncertainty. Dipmeter and image log interpretation is based on the assumption that some beds, commonly low-energy deposits, were deposited horizontally. However, salt domes commonly develop at structural discontinuities, such as above basement faults or at breaks in depositional slope, so this assumption should be applied with caution. Core calibration and an appreciation of the structural history of the salt play are essential to arrive at meaningful interpretations. The workflow described in this chapter is used to derive structural dips from dipmeter and logging-while-drilling (LWD) image logs for a typical salt flank play. This interpretation, complementary to seismic, is an additional calibration for local structure in poorly imaged areas. We show how structural scenarios were derived and reconciled with actual drilling results. This example demonstrates the usefulness of commonly run dipmeter, image log, and LWD data in calibrating seismic interpretations where seismic resolution is poor. Copyright © 2010 by The American Association of Petroleum Geologists. Source

Garcia Barneto A.,University of Huelva | Carmona J.A.,University of Huelva | Barron A.,CEPSA Inc
Energy and Fuels

The thermal degradation profile for any type of oil-based sample under thermogravimetric analysis (TGA) conditions exhibits three distinct stages, namely, vaporization from room temperature to 340-350°C, cracking from 340-350°C to 480-500°C, and char oxidation from 500°C to 570°C. The former two stages occur in both inert (nitrogen) and oxidative (air) environments, whereas the latter only occurs in the presence of oxygen. Deconvoluting thermogravimetric data allows one to estimate the composition of oil derivatives with a view to expeditiously obtaining useful information from a refining process. To this end, thermal degradation of crude oil and its main refining cuts were modeled here by using the smallest possible number of representative pseudo-components. In order to ensure accurate fitting of thermogravimetric results, mass losses were interpreted in terms of autocatalytic kinetics. Fitting to an nth-order kinetics was useful below 350°C (vaporization), but not above this temperature, because of cracking with fast mass losses in the vicinity of certain temperatures. This modeling scheme for thermogravimetric results afforded the following conclusions: (i) atmospheric gas-oil typically contains 10% residual kerosene fraction; (ii) atmospheric residue still contains 35-45% distillable compounds; (iii) the main component of visbreaking feed (nearly 66%) degrades at a similar temperature as asphaltenes; (iv) visbreaking residue is similar to feed at high temperatures but contains light components similar to naphtha or gas-oil, which vaporize at low temperatures; and (v) simulating crude oil allowed us to estimate the potential production of distillates (62.93% from heavy crudes and 79.61% from light crudes). Such useful information can be used by process engineers to assess the performance of equipment such as distillation columns or visbreaking units, and also to estimate the quality of some streams, such as atmospheric gas-oil or visbreaking feed. © 2015 American Chemical Society. Source

Garcia-Carballido C.,Maersk Oil | Garcia-Carballido C.,CEPSA Inc | Boon J.,Royal Dutch Shell | Tso N.,Royal Dutch Shell
AAPG Memoir

Numerous dipmeter and borehole image log data sets have been acquired over the years and are being used to build subsurface models. Dealing with dipmeter and image log data remains a niche skill within the petroleum industry, and because these are not conventional log data sets, they tend to be neglected in the way data are stored and quality controlled. A variety of wireline and logging-while-drilling tools exist, and each logging run contains a variety of curves with tool-specific mnemonics. For a particular data set, there may be several tens of curves from the raw data set and hundreds from the processed and interpreted data sets. Data quality control (QC) is an essential procedure that has to be conducted to assure dipmeter and image log data integrity in the subsurface models. Data QC should be performed iteratively during data acquisition, data management, processing, and interpretation. This chapter presents standard and globally applicable corporate guidelines for data management and data QC of dipmeter and image log data sets. Copyright © 2010 by The American Association of Petroleum Geologists. Source

Barneto A.G.,University of Huelva | Carmona J.A.,University of Huelva | Garrido M.J.F.,CEPSA Inc
Thermochimica Acta

Monitoring asphaltenes is very important with a view to optimizing visbreaking units in oil refineries. Current analyses based on selective dissolution in different solvents are slow, so new, more expeditious methods for measuring asphaltenes are required to facilitate fuel-oil production. In this work, we studied the thermal degradation of asphaltenes as the potential basis for a thermogravimetric method for their monitoring in visbreaking streams. The thermal degradation of asphaltenes occurs largely from 400 to 500°C; the process is quite smooth in an inert environment but involves several fast mass loss events in the air. Kinetic parameters for characterizing the process were determined by using two model-free methods and the modified Prout-Tompkins kinetic equation to examine asphaltene thermolysis. Both types of methods showed the activation energy to increase during pyrolysis but to remain almost constant during cracking in the presence of oxygen or even diminish during char oxidation. Deconvoluting the thermogravimetric profiles revealed that asphaltene thermolysis in the air cannot be accurately described in terms of an nth order kinetic model because it involves some acceleratory phases. Also, thermogravimetric analyses of visbreaking streams revealed that char production in them is proportional to their asphaltene content. This relationship enables the thermogravimetric measurement of asphaltenes. © 2016 Elsevier B.V. All rights reserved. Source

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