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Dr. Christopher Wibberley is a senior technical advisor at TotalEnergies, France, specializing in structural geology, hydrodynamics and seals. After studying geology at Oxford (B.A. degree), and Leeds (Ph.D. in basement tectonics, 1995), Chris held university research positions at Montpellier, Kyoto and Cambridge (CASP) until moving again to France where he obtained his senior research habilitation as a university lecturer in Nice – Sophia Antipolis before moving to Total in 2007. Chris has progressed through various positions both in Total's headquarters providing specialist technical support for projects, and in the Total EP Congo affiliate as an exploration geologist. He now performs a role of technical advisor to a wide variety of exploration, reservoir development, CCS and R&D projects. His research aims to improve quantification and prediction of fluid flow and geomechanical behaviour of faults and fracture systems in the Earth's crust, applying this research from petroleum E&P to seal integrity in CCS, induced seismicity and understanding tectonic processes.
Abstract Super duplex stainless steel tubes in grade SAF2507 have long been used for umbilical application in deep water oil and gas subsea systems. One of the oldest subsea systems installed with super duplex stainless steel tube SAF2507 is at the Åsgard oilfield located in the Norwegian Sea about 200 km offshore of the north part of Norway (figure 1). The Åsgard field comprises of the Midgard, Smørbukk and Smørbukk South deposits, which were discovered in 1981, 1984 and 1985 respectively. Corrosion evaluation of the tubes was presented at EUROCORR 2016, Montpellier, France, September 16th 2016 by Cathrine Holager, Materials Engineer (Aker Solutions) and authored by Karin van Thoor (Aker Solutions) and Sophia Ekman (Sandvik Materials Technology R&D) with the title of "Corrosion Assessment of the 17-year old Åsgard Smørbukk Umbilical". In addition to the previous report, this following article will report on the investigation of the fatigue properties of the tubes in two sections of the umbilical tubing installed in this field. Samples were taken from different areas of the dynamic umbilical, i.e. the splash zone and the most dynamic zone, and evaluated by fatigue testing. High frequency fatigue tests were performed on the samples and showed that fatigue properties did not differ significantly. The tests showed insignificant reduction in the fatigue strength of the tubes used both in the most dynamic part and splash zones. In addition, mechanical properties were evaluated to understand the effect of deformation history from fabrication, service life and sample preparation. No significant effect, besides a slight hardness increase compared to the delivery condition, was observed.
Abstract Geological and hydrological data collected at the Terrieu experimental site north of Montpellier, in a confined carbonate aquifer indicates that the aquifer is highly heterogeneous and both fracture clusters and an important bedding plane serve as the main flow paths. However, difficulties in characterising the geometry and location of the main flow channels and in estimating their flow properties have led to significant uncertainties in modelling the hydrodynamic behaviour of the aquifer. This challenge of reducing these uncertainties can be addressed by solving an inverse problem using the available geological and hydrological data as constraints. We first constructed a 2D equivalent porous medium model by using a transition probability geostatistical approach to represent the test site domain, on which the inverse modelling was performed. A hybrid stochastic-Newton Markov Chain Monte Carlo (MCMC) sampler was used to determine the transmissivity fields on the experimental site scale through the inversion of the steady-state data recorded at 22 boreholes during 8 interference tests. In addition, we used the data from outcrop, borehole fracture characterisations and interpretations of inter-well connectivities from interference test responses to constrain the spatial variability models of the flow properties. Constraints for hydraulic conductivities, based on analytical interpretations of pumping tests, are also added to the inversion model. By following the above approach, transmissivity fields that produce similar hydraulic behaviours to the real head measurements were obtained. The inverted transmissivity fields show complex spatial heterogeneities with highly conductive channels embedded in a low transmissivity matrix region. The spatial trend of the main flow channels is in good agreement with that of the main fracture sets mapped on outcrops in the vicinity of the Terrieu site suggesting that the hydraulic anisotropy is consistent with the structural anisotropy. These results reduce the uncertainties in predicting fluid flow in the subsurface and improve the hydrogeological understanding of the groundwater flow system within the fractured carbonate rocks. In addition, they quantify the magnitude of the hydraulic conductivity of the main flow paths.
ABSTRACT This paper focuses on the design and control of a new Autonomous Underwater Vehicle (AUV) named H160. The first prototype of this AUV has been designed through a collaboration of two partners, which are the LIRMM laboratory and ECA-HYTEC company. We present an overview of this project regarding the development of this vehicle including the software and hardware architecture, modelling and control. In addition, the first experimental results relying on real experimental conditions are displayed and commented. INTRODUCTION Underwater robotic vehicles are helpful equipment for scientists to explore oceans and seas. Many examples have revealed that ROV (Remotely Operating Vehicle) and AUV are used for diverse applications such as inspection, object recovery or surveys. We can distinguish a "depth limit" for the different types of existing AUV. Indeed, from about 300 meters, the structure, the dimensions and the characteristics of these vehicles change. On the one hand, the AUVs specified for deep water, as for example Hugin 3000 from Kongsberg Simrad, Sea Oracle from Bluefin Robotics and Alistar 3000 from ECA, have a maximum depth of 3000 meters, a high autonomy, nonnegligible dimensions and a weight that requires a heavy logistic. On the other hand, some AUVs (Remus from Hydroid, Gavia from Hyfmind) with less autonomy, reduced dimensions, more modular parts and a reduced logistic, are the perfect tool for the investigation of shallow water. In the context of partnership between the LIRMM (Montpellier Laboratory of Computer Science, Robotics and Microelectronics) and the french company HYTEC (specialist in the design and manufacture of remote controlled systems in "hostile" environments), the first prototype of AUV H160 has been developed. In 2004, our original choice was positioned on a small vehicle with a 2 to 4 knots forward speed for 3 or 4 hours mission duration, with a reduced logistic.
Abstract Harmonic testing for obtaining dynamic reservoir information was first proposed some thirty years ago. Although not much used in the oil industry, interest in the method is revived periodically, mostly for the determination of skin effect and near-wellbore permeability. This paper looks at the practical aspects of using periodic rate variations for testing oil wells. It is shown that such tests can provide the same information as conventional well tests and can be interpreted in the same way. Their main advantage is that they do not require fluids to be brought to surface in exploration or early appraisal testing, or wells to be shut-in in production testing. They also provide data that are less affected by measurement errors and wellbore effects such as multiphase flow or phase redistribution. The main limitation is that, for the same radius of investigation, harmonic tests are significantly longer than conventional tests. Consequently, they cannot be used for reservoir characterization in exploration and appraisal wells. They appear well suited, however, for monitoring reservoir changes from production wells. Introduction The concept of harmonic testing was first proposed by Kuo in the early 70's, as an extension of pulse testing.Pulse tests aim at generating interference data between two wells through a sequence of alternating production and shut-in periods in order to obtain intra-well reservoir properties and were believed to be more practical than interference tests. Kuo's suggestion was to use a periodic production history in a single well to determine the well near-wellbore properties. If the well is produced at a sinusoidal (or at least periodic) rate, the resulting pressure drop is also periodic, after early transients have died out and a pseudo-steady regime is established. As in pulse tests, the amplitude and phase lag of the pressure relative to the flow-rate can be measured and matched with the response of an interpretation model to obtain the corresponding reservoir parameters. The analysis is performed in the frequency domain instead of the time domain. Rosa and Horne offered a comprehensive review of previous publications on the subject. Many aspects of harmonic testing were studied in the late 70's and early 80's by Jouanna and co-workers at the university of Montpellier, France. They developed a number of well test interpretation models in the frequency domain and identified some of the difficulties inherent to the method. They also designed several testing devices and performed experiments in the laboratory and in shallow water wells. They concluded that harmonic testing could provide reservoir parameters such as skin factor, damaged zone depth, permeability and the group fct. They pointed out, however, that inertia effects and fluid-solid coupling should be included to fully understand the experimental results. Pan recently investigated harmonic testing in the medium frequency range (0.01Hz-10Hz), where more than just Darcy flow is involved. Her work focused on the identification of pore structure properties and the upscaling of these properties to infer the macroscopic behavior of the porous medium. She also suggested that wells could be stimulated by increasing effective reservoir permeability and porosity with elastic wave periodic excitation, thus providing higher flow-rates. Another example of frequency-domain analysis of pressure behavior has been presented by Firoozabadi and Chang, who showed that reservoir compressibility and permeability can be estimated from the analysis of pressure data influenced by tidal effects. The input signal is a fixed gravitational potential variation instead of an imposed flow-rate variation and their analyses use two frequencies only (diurnal and semi-diurnal). An important development in harmonic testing came from Mercier, who showed that the derivative of the pressure modulus in the frequency domain had a behavior similar to that of the pressure derivative in conventional well test analysis. She therefore concluded that the interpretation methodology developed for conventional tests could be applied to harmonic tests.
ABSTRACT: The tunnel across the Pyrenees, joining by a high speed train Barcelona (Spain) and Montpellier (France), will have a total length of 8200m. In order to characterise the rock mass, several site investigations, in situ and lab tests have been performed. Also, a full scale gallery has been built at the weakest part of the predicted profile. INTRODUCTION In the liaison by a High Speed Railway between Barcelona (Spain) and Montpellier (France), the cross of the Pyrenees is projected to be done throughout the "Le Perthus Tunnel", with an approximated length of 8200m. The studies for this tunnel are included in the binational stretch: "Figueres-Perpignan", approximately 42km long, and conducted by the European Group of Economical Interest AEIE/GEIE Sur Europa Mediterráneo/ Sud Europe Mediterranée, co-ordinated by technicians of the Spanish and French National Railway Companies RENFE and SNCF, as well as from the Ministry of Transport in both countries. The studies of the Perthus Tunnel have their background on the projects successively conducted by SNCF and FGC (Ferrocarrils de la Generalitat de Catalunya) between 1989 and 1994. Several locations and lengths for this tunnel have been considered, but finally the cross of the Pyrenees will be done under Le Perthus village, between the villages of La Jonquera in Spain and Le Boulou in France. As for the geotechnical model, several in situ and lab tests were carried out and more recently (GEOCONTROL, 1998) the construction of an experimental shaft and gallery at Le Boulou (France) was made, crossing some weak silurian ampellites and the myllonites of Le Boulou fault, making several complementary tests and an extensive instrumentation programme (borehole slotter, extensometer, convergence, stress sensors, etc.). All this information has been analysed in order to estimate the strength and deformability properties of rock mass.
Abstract Exploration sites in tropical forests have historically been left unrestored, requiring the natural ecological succession cycle to reestablish the tertiary hardwood forest. Conoco and the University of Montpellier have been cooperating in a study of planting "macro-cuttings" to accelerate tree growth for site restoration in Gabon. Macro-cuttings are typically 3 m (10 ft.) long and 10–30 cm (4–12 in.) in diameter. The cuttings are cut from the trunk, branches or crown of a tree. For the purposes of this study, cuttings from 50 local tree species were planted in varying soil and light conditions. In addition to those macro-cuttings planted at the time of cutting, some of the cuttings were sealed with wax and stored for two months. These were then planted in the same manner as the original, unwaxed cuttings. This storage method simulated the use of cuttings cut during site construction and used for later restoration at exploration sites. The use of "macro-cuttings" raises the tops of the cuttings above planted or naturally occurring primary and secondary growth. This improves the competitive position of these trees relative to seedlings of the same species. If successful, this process would accelerate site recovery to tertiary growth conditions at a location by several growing cycles, providing a cost-effective and sustainable means of enhanced site restoration. Sites used for the study were in Gabon at an abandoned Conoco camp site in Ezanga and at the Gabon Makokou research facility. First year results were mixed but encouraging. Second year results were affected by elephants having destroyed much of the site at Ezanga. There was, however, sufficient progress at Makokou to continue the study. The most recent results indicate 14 different species with observed shoot growth. Although the study is still ongoing, the practices employed and the successes realized suggest that the use of macro-cuttings to accelerate site restoration may prove to be practical and cost-effective. Introduction Exploration in tropical rain forests often requires clearing of temporary sites for camps, helipads, drilling locations and roads. P. 611^
RESUME L'auteur passe en revue les régions géologiques dans lesquelles on peut espérer découvrir des gisements de pdtrole en France. En donnant l'interprétation géologique des iravaux de recherche qui ont porté jusqu'à présent SUT ces régions, en examinant les conditions de structure et de sédimentation, il ddtermine les principaur facteurs qui doivent orienter ces recherches. Il montre en particulier que la zone subpyrénéenne prdsente des indices nombreux et fort abondants, mais que la fosse uturienne sur l'emplacement de laquelle on les observe, n'offre pas de roci~esmagasin susceptibles de contenir du pétrole en quantitd exploitable. La bordure de cette fosse, oli le Cénomanien est transgessif Tépondrait sans doute aux conditions requises pour la formation des gisements de .pétrole. L'exploration de cette zone sera difficile en raison de la couverture discordante de Miocène qui la masque. Le Languedoc manifeste des indices de pdtrole très encourageants en bordure des Cevennes et de la Moitagne Noire, et de belles structures au Nord et ir. l'Ouest de Montpellier. Nous savons cependant peu de choses concernant le niveau pétrolifère et la migration qui a donné naissance aux indices de Gabian et de la vallée de la Vis au Sud de Ganges. L'auteur donne enfin les raisons de penser que les recherche8 de petrole dans le Jura ne présentent pas beaucoup d'attrait. SUMMARY T he paper reviews the geological regions in which we can hope to detect oilfields in France. RI! giving the geological interpretation of the research works ' which up to the present time have borne on those regions, and by examining the structural and sedimentar 11 conditions, he ascertains the principal elements which art? to guide such searchinq. Especially he shows that the suboyrenean zone offers numerous und valuable seepages, but that Aturian geosynclinaì on the spot of which they are observed does not present reservoir rocks able to contain oil in industrial quantity. The marqins of this geosyncline where the Cenomanian is overlappinq, miqh t answer to the conditions fauourable to the formation of oil-fields. The workinq of this zone will be difficult because the Cretaceous structures are tarried under the Miocene discording cover. Languedoc evidences Cil seenaqes which are vemj hone'ull on the sedimentarvi margin of the Cevenne anc Montaqne Noirp, and promisinn structures to the Rorth and the West of Montpellier. However we know veril little concerninq the oilhearing Strata and the miqration which has given birth to the oil-evidences of Gabian and of the Vis-valleil, South of Ganges. Lastly the paper gives the reasons the reporter has to think that the oil-search in the Jura does not offer much favowrable outlook. AUSZUG Der Verfasser gibt eine Uebersicht über die geologischen Cebieie, in die Au'findung von Erdollagerstatt