Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vi, 84 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 79-82).

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: A. Daniel Hill. Vita. Includes bibliographical references.

No description available.

In addition to its various military applications, shaped charges have been used in oil industry as an oil well perforator (OWP) to connect oil and gas to their reservoirs. The collapse of the liner material under the explosive load produces a hypervelocity jet capable of achieving a deep penetration tunnel into the rock formation. The achieved penetration depends on the OWP design, which includes the geometry and the material of the explosive and the liner as well as the initiation mode and the casing of the shaped charge. The main purpose of this research is to assess the performance of OWP with different design aspects in terms of its penetration depth into concrete material.This research employed the Autodyn finite difference code to model the behaviour of OWPs in the stages of liner collapse, jet formation and jet penetration. The design parameters of OWPs were studied quantitatively to identify the effect of each individual parameter on the jet characteristics and the jet penetration depth into concrete material according to the API-RP43 standard test configuration. In order to validate the Autodyn jetting analysis, this research compared the jetting simulation results of copper OWP liners with those obtained from flash x-ray measurements while the numerical jet penetration into the laminated concrete target was validated experimentally by the static firing of OWPs. Above-mentioned experiments were designed and performed in this project.The validated hydrocode was implemented in this research to study the effects of the concrete target strength, the liner material and the liner shape on the jet penetration depth into concrete targets.For the target strength, the traditional virtual origin (VO) penetration model was modified to include a strength reduction term based on Johnson’s damage number and the effect of the underground confinement pressure using Drucker-Prager model. The VO analytical model is also implemented in the liner material study to account for the jet density reduction phenomena and its induced reduction of jet penetration capability. The jets obtained from machined copper and zirconium liners and from copper-tungsten powder liner all exhibited the density reduction phenomena. The modified VO model considers the non-uniform distribution of jet density based on the jet profile analysis using Autodyn and the experimental soft recovery for some tested liners. The results lead to a modified VO penetration model including the non-uniform jet density effect.For zirconium liner material, numerical and analytical studies were conducted for different flow velocities and different collapse angles in order to determine the boundaries between the jetting and non-jetting phases and whether a coherent or a non-coherent jet will form. This study indicated that the suggested four different liner shapes (i.e. the conical, the biconical, the hemispherical and the bell) will produce coherent jet when the zirconium is used as OWP liner.The validated Autodyn hydrocode is also used in this thesis to calculate the velocity difference between two neighbouring zirconium jet fragments. The velocity difference is related directly to the breakup time of an OWP jet, and thus, it is calculated for a range of zirconium liners with different liner wall thicknesses. The calculated values of velocity difference gave a clear insight for the breakup time formulae for zirconium jet in terms of the liner thickness and the charge diameter.

Made available in DSpace on 2014-12-17T14:07:06Z (GMT). No. of bitstreams: 1 BrunoLSC_DISSERT.pdf: 3848053 bytes, checksum: 28828821b0f45645fb6dc741dc2505bf (MD5) Previous issue date: 2013-09-28 / One of the great challenges at present time related with the materials area concerns of products and processes for use in petroleum industry, more precisely related to the Pre-salt area. Progresses were reached in the last years allowing the drilling of the salt layer, with the time reduction for drilling and larger success at the end. For the oil wells companies the preponderant factor is the technology, however, in spite of the progress, a series of challenges is still susceptible to solutions and one of them refers to the slurries preparation for cementing in those areas. Inside of this context, this study had for objective to analyze the influence of the salts NaCl, KCl, CaSO4 and MgSO4 in strength and chemical structure of the hydrated products. As methodology, they were prepared and analyzed cement slurries with varied concentrations of these salts that are commonly found in the saline formations. The salts concentrations used in formulations of the slurries were of 5%, 15% and 30%. The slurries were formulated with specific weight of 15,8 lb / gal and the cement used was Class G. Strength tests were accomplished in samples cured by 24 hours and 28 days. Also were realized crystallographic characterization (XRD) and morphologic (SEM). In agreement with the presented results, it is observed that the largest resistance values are attributed to the slurries with concentration of 15%. There was reduction of the strength values of the slurries formulated with concentration of 30%. Through the characterization microstructural it was possible to note the salts influence in the main cement hydrated products / Um dos grandes desafios da atualidade relacionado com a ?rea de materiais diz respeito ? produ??o de produtos e processos para uso na ind?stria do petr?leo, mais precisamente relacionado ? ?rea do Pr?-sal. Avan?os foram alcan?ados nos ?ltimos anos permitindo a perfura??o da camada de sal, com a redu??o do tempo para perfura??o dos po?os e maior ?xito ao final da opera??o. Apesar dos avan?os, uma s?rie de desafios ainda ? pass?vel de solu??es e um deles refere-se ? prepara??o de pastas para a cimenta??o de po?os nessas zonas com camadas evapor?ticas. Dentro deste contexto, este estudo teve por objetivo analisar a influ?ncia dos sais NaCl, KCl, CaSO4 e MgSO4 no comportamento mec?nico e estrutura qu?mica dos produtos hidratados. Como metodologia, foram preparadas e analisadas pastas de cimento com concentra??es variadas destes sais que s?o comumente encontrados nas forma??es salinas do reservat?rio do Pr?-sal. As concentra??es dos sais empregadas nas formula??es das pastas foram de 5%, 15% e 30%. As pastas foram formuladas com peso espec?fico de 15,8 lb/gal e o cimento utilizado na prepara??o das pastas foi o do tipo Portland Classe G. Foram realizados ensaios de resist?ncia ? compress?o em corpos de prova curados por 24 horas e 28 dias. Tamb?m foram realizados ensaios de caracteriza??o cristalogr?fica (DRX) e morfol?gica (MEV). De acordo com os resultados apresentados, observa-se que os maiores valores de resist?ncia s?o atribu?dos ?s pastas com concentra??o de 15 % para todos os sais. Houve, tamb?m, redu??o dos valores de resist?ncia das pastas formuladas com concentra??o de 30 % para todos os sais. Atrav?s das an?lises de caracteriza??o micro estrutural foi poss?vel observar a influ?ncia dos sais nos principais produtos hidratados do cimento Portland

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La prédiction des propriétés mécaniques des matériaux cimentaires nécessite d'un modèle intégrant l'hydratation progressive du matériau, le couplage entre la consommation d'eau et les contraintes et l'historique des charges appliquées. Ceci est particulièrement important lors de la modélisation du comportement de la gaine de ciment des puits pétroliers qui est soumise, dès son plus jeune âge, à une large gamme de chargements mécaniques et thermiques qui pourraient avoir un effet négatif sur ses propriétés mécaniques. L’objectif de cette thèse est de fournir un cadre de modélisation pour le comportement hydro-mécanique d'une pâte de ciment pétrolier dès son plus jeune âge jusqu'à son état durci. Le manuscrit est divisé en deux parties. Partie I : cinétique d'hydratation L’évolution des propriétés physiques des matériaux cimentaires est contrôlée par l'avancement des réactions d'hydratation. Deux approches de modélisation sont présentées:- Un cadre théorique pour la modélisation de l'hydratation du ciment est développé comme une extension des modèles de nucléation et de croissance classiques. Le modèle multi-composants proposé considère explicitement le ciment anhydre et l'eau comme des phases indépendantes participant à la réaction. Un taux de croissance est introduit qui permet de représenter sous une forme mathématique unique la croissance linéaire ainsi que la diffusion parabolique. La formulation introduit naturellement des paramètres des mélanges cimentaires tels que la composition de la poudre de ciment, les densités des différentes phases, le rapport eau/ciment, le retrait chimique et les propriétés des hydrates. Les différents mécanismes de contrôle de la réaction sont identifiés sur la base du modèle physique proposé.- Une loi générale de la cinétique d'hydratation basée sur la théorie des transformations en phase solide est proposée. Cette formulation est comparée aux lois d'évolution trouvées dans la littérature et contribue à fournir une explication physique qui pourrait aider à la compréhension de la cinétique d'hydratation du ciment. Dans les deux cas, les modèles cinétiques sont calés sur une série de résultats expérimentaux. Partie II : loi de comportement mécanique Le comportement mécanique de la pâte de ciment est décrit dans le cadre des milieux poreux réactifs. La pâte de ciment est modélisée en tant que matériau poreux multi-phases avec une loi constitutive élasto-visco-plastique, dont les paramètres dépendent du degré d'hydratation. Le retrait chimique de la pâte de ciment et la consommation d'eau pendant l'hydratation sont pris en compte dans la détermination des déformations macroscopiques. L’évolution des paramètres poroélastiques de la pâte de ciment lors de l'hydratation est calculée à l’aide d'un modèle micromécanique. Une surface de charge asymétrique avec des seuils de compression et de traction est adoptée pour le régime plastique, avec des mécanismes d’écrouissage tenant compte à la fois des déformations plastiques accumulées et du degré d'hydratation. Le comportement visqueux est basé sur les notions de la théorie de solidification. Une courbe de rétention d'eau est introduite pour tenir compte de la désaturation potentielle du matériau lors de l'hydratation. Les paramètres du modèle pour une pâte de ciment pétrolier classe G sont évalués en simulant des expériences de chargement mécanique dans un dispositif spécialement conçu pour tester le comportement thermo-mécanique de la pâte de ciment dès le début de l'hydratation. Le modèle prédit avec une bonne précision la réponse d'une pâte de ciment en cours d’hydratation lorsqu'elle est soumise à divers chemins de chargement dès son plus jeune âge. L'importance de l'histoire de chargement est mise en évidence, ainsi que la nécessité de la détermination des contraintes effectives tout au long de la vie du matériau / The prediction of the performance of cement-based materials requires a holistic model integrating the progressive hydration of the material, the coupling between water consumption and strains, and the history of the applied loadings. This is particularly important when modelling the behavior of the cement sheath in oil wells which is subjected, from its earliest age and during its lifetime, to a wide range of mechanical and thermal loadings that could have a detrimental effect on its future mechanical properties. The aim of the present thesis is to provide a complete modelling framework for the hydro-mechanical behavior of an oil well cement paste from its earliest age to its hardened state. The manuscript is divided in two parts. Part I: Hydration kinetics The evolution of the most significant physical properties of cement-based materials is controlled by the advancement of the hydration reactions. Two different modelling approaches are presented:- A theoretical framework for the modelling of cement hydration is developed as an extension of classical nucleation and growth models. The proposed multi-component model explicitly considers anhydrous cement and water as independent phases participating in the reaction. We also introduce a growth rate that encompasses linear as well as parabolic diffusion growth in a single continuous mathematical form. The formulation naturally introduces some of the most relevant parameters of cement paste mixtures, such as the cement powder composition, mass densities of the different phases, water to cement ratio, chemical shrinkage and hydrates properties. The different rate-controlling mechanisms can be identified and interpreted on the basis of the proposed physical model.- A general hydration kinetics law based on the theory of solid phase transformations is proposed. This formulation is compared with the evolution laws found in the literature and helps providing a physical explanation that could shed light on the understanding of cement hydration kinetics. In both cases, the kinetic models are calibrated over a series of experimental results in order to properly evaluate the quality of the predictions. Part II: Mechanical constitutive law The mechanical behavior of cement paste is described in the framework of reactive porous media. The cement paste is modelled as a multi-phase porous material with an elastic-viscous-plastic constitutive law, with mechanical parameters depending on the hydration degree. Furthermore, the cement paste chemical shrinkage and pore water consumption during hydration are accounted for in the determination of the macroscopic strains. The evolution of the poroelastic parameters of the cement paste during hydration is calculated by means of a micromechanical upscaling model. An asymmetric yield surface with compressive and tensile caps is adopted for the elastoplastic regime, with hardening mechanisms considering both the cumulated plastic deformations and the hydration degree. The viscous behaviour is based on the notions of solidification theory. A water retention curve is introduced to account for the potential desaturation of the material during hydration. The model parameters for a class G cement paste are evaluated by simulating the results of mechanical loading experiments in a device specially designed for testing the thermo-mechanical behavior of cement paste from the early stages of hydration. The results show that the proposed model predicts with good accuracy the response of a hydrating cement paste when subjected to various loading paths from its early age. The importance of the loading history is outlined, as well as the need for the accurate determination of the effective stresses throughout the life of the material

Na perfuração de poços para extração de petróleo são utilizados fluidos de perfuração compostos por diversos produtos químicos com finalidades específicas em função das características de cada poço. Durante vários anos utilizou-se fluido a base de óleo diesel, devido à excelente performance proporcionada à perfuração. O aumento da preocupação ambiental levou a indústria do petróleo a elaborar composições de fluidos que fossem menos agressivas ao ambiente e, ao mesmo tempo, apresentassem performances semelhantes à do fluido base óleo diesel, destacando-se na atividade de perfuração na bacia do Recôncavo, Bahia, o fluido n-Parafina. Entre os compostos de interesse ambiental presente neste tipo de fluido, destacam-se a n-Parafina e cloretos, algumas vezes com traços de BTEX (benzeno, tolueno, etilbenzeno e xilenos). Como durante a perfuração podem ser atravessados aqüíferos portadores de água doce, resta a preocupação de que o contato desses fluidos com estes aqüíferos possa gerar problemas de contaminação ambiental. Este trabalho apresenta uma avaliação de situações de poços, onde o aqüífero São Sebastião, principal da bacia do Recôncavo, foi atravessado utilizando-se fluido n-Parafina. A avaliação foi baseada em simulações matemáticas do transporte dos compostos encontrados no fluido n-Parafina e em amostras coletadas a partir de testes de formação a cabo durante a perfuração dos poços. A partir da simulação destes valores reais, pôde-se concluir que, a menos de 0,5 m da parede dos poços, as concentrações encontram-se perfeitamente dentro dos padrões de potabilidade para todos os compostos analisados. De acordo com a metodologia utilizada, as utilizações do fluido n-Parafina são ambientalmente inofensivas como fluido de perfuração a ser utilizado neste tipo de cenário hidrogeológico. / The use of drilling fluids or muds is standard practice in oil industry. The composition of these fluids is designed according to the formation and the well properties. For many years oil- based muds (OBM) had a worldwide use because they offered advantages over water-based muds (WBM). Increasing environmental concern led the oil industry into the formulation of a variety of syntetic organic based mud (SBM) or low-tox mineral oil- based mud, like the n-parafin based mud, with a large use at the Reconcavo Basin, Bahia, Brazil. Some of the compounds that are common to most fluid formulas are considered potential environmental contaminants, among them n-parafin and chloride, sometimes with trace BTEX (benzene, toluene, ethylbenzene and xylenes). The drilling of the well might cross aquifers that are used for drinking purposes before reaching the oil reservoir and the contact of the water with the drilling fluid might pose some concern about the aquifer contamination. This paper presents case studies where a well penetrated São Sebastião Aquifer, in Reconcavo Basin, using n-Parafin based mud and a mathematical model was applied to simulate the fate and transport of the compounds found in fluid and samples collected during the drilling. The results indicated that all concentration values of the detected compounds were well below water drinking standards within 0,5 m from the well. According to this conclusion, the use of the n-parafin fluid is considered harmless to the environment and is recommended for similar geological scenarios.

This is the first academic study of well costs and drilling times for Australia???s petroleum producing basins, both onshore and offshore. I analyse a substantial database of well times and costs sourced from government databases, industry and over 400 recent well completion reports. Three well phases are studied - Pre-Spud, Drilling and Completion. Relationships between well cost factors are considered, including phase time, phase cost, daily cost, rig day rate, well depth, basin, rig type, water depth, well direction, well objective (e.g. exploration), and type of completion (P&A or producer). Times and costs are analysed using scatter plots, frequency distributions, correlation and regression analyses. Drilling times are analysed for the period 1980 to 2004. Well time and variability in well time tend to increase exponentially with well depth. Technical Limits are defined for both onshore and offshore drilling times to indicate best performance. Well costs are analysed for the period 1996 to 2004. Well costs were relatively stable for this period. Long term increases in daily costs were offset to some extent by reductions in drilling times. Onshore regions studied include the Cooper/Eromanga, Surat/Bowen, Otway and Perth Basins. Offshore regions studied include the Carnarvon Basin shallow and deepwater, the Timor Sea and Victorian Basins. Correlations between regional well cost and well depth are usually high. Well costs are estimated based on well location, well depth, daily costs and type of completion. In 2003, the cost of exploration wells in Australia ranged from A$100,000 for shallow coal seam gas wells in the Surat/Bowen Basins to over A$50 million for the deepwater well Gnarlyknots-1 in the Great Australian Bight. Future well costs are expected to be substantially higher for some regions. This study proposes methods to index historical daily costs to future rig day rates as a means for estimating future well costs. Regional well cost models are particularly useful for the economic evaluation of CO2 storage sites which will require substantial numbers of petroleum-type wells.

by Andrew Loris Kurkjian. / Originally published as thesis (Dept. of Electrical Engineering and Computer Science, Ph.D., 1982). / Bibliography: p. 186-189. / Supported in part by the Advanced Research Projects Agency monitored by ONR under Contract N00014-81-K-0742 NR-049-506 Supported in part by the National Science Foundation under Grant ECS80-07102