This study proposes a new, easily applied method to quantify uncertainty in production forecasts based on reservoir simulation. The new method uses only observed data and mismatches between simulated values and observed values as history matches of observations progress to a final "best" match. The method is applicable even when only limited information is available from a field. Previous methods suggested in the literature require more information than our new method. Quantifying uncertainty in production forecasts (i.e., reserve estimates) is becoming increasingly important in the petroleum industry. Many current investment opportunities in reservoir development require large investments, many in harsh exploration environments, with intensive technology requirements and possibly marginal investment indicators. Our method of quantifying uncertainty uses a set of history-match runs and includes a method to determine the probability density function (pdf) of future oil production (reserves) while the history match is evolving. We applied our method to the lower-Pleistocene 8-Sand reservoir in the Green Canyon 18 field, Gulf of Mexico. This field was a challenge to model because of its complicated geometry and stratigraphy. iv We objectively computed the mismatch between observed and simulated data using an objective function and developed quantitative matching criteria that we used during history matching. We developed a method based on errors in the mismatches to assign likelihood to each run, and from these results, we determined the pdf of reservoir reserves and thus quantified the uncertainty in the forecast. In our approach, we assigned no preconceived likelihoods to the distribution of variables. Only the production data and history matching errors were used to assess uncertainty. Thus, our simple method enabled us to estimate uncertainty during the history-matching process using only dynamic behavior of a reservoir.

No description available.

In the petroleum industry, accurate estimates of hydrocarbon reserve and its producibility are without a doubt among the most important issues. Quantitative estimates require the knowledge of three basic parameters of the rock formation: the porosity &phis;, the water saturation S w and the permeability k. Electrical conductivity is one of the most commonly made measurements used to deduce these quantities. Some empirical relationships used to make such estimates are quite well established and understood, however, many still lack a sound scientific foundation. Systematic laboratory investigation and theoretical understanding of the underlying petrophysics are much needed. This dissertation consists of three projects aimed at understanding both the surface conductivity observed in shaly sandstone, and the related phenomena of molecular adsorption on heterogeneous surfaces. In the first project, we carried out nitrogen adsorption experiments on three shale samples whose fractal dimensions had been previously characterized by small angle scattering (SANS). We found that analyzing the adsorption isotherm data according to the available theoretical predictions always resulted in D values that are lower than those obtained by SANS. The second project, a numerical simulation of adsorption on fractal surfaces, was designed to understand the origin of discrepancies revealed in the first project. We found that the interplay between van der Waals adsorption and capillary condensation always leads to a crossover between the two theoretical limits. The simulated isotherms exhibit the same general features we observed in our experimental data. The third project was aimed at understanding the surface conduction in porous media. We isolated the surface conductivity by growing water layers on the surface with water adsorption isotherm technique. Some of our results indicate that AC impedance measurement could let us determine the surface conductivity and separate it from that of the bulk, thereby more accurate estimates of oil saturation can be achieved in using the empirical Archie's relation. Our studies shed more light on the various aspects of the surface ionic conduction, including Debye - Hückle length, CPA phenomenon, and effects of saturation, cation species, temperature, and substrate.

Variable atmosphere pyrolysis of Tosco Oil Shale was performed utilizing a Chemical Data Systems 320 concentrator and a gas blending system. Flame ionization (FID) and nitrogen specific (NPD) detection were performed to determine the atmosphere which maximized hydrocarbon compound formation while minimizing nitrogen compound formation. Comparisons of FID and NPD peak areas as a function of temperature are given for 0%, 10%, 15% and 30% oxygen. The NPD peak areas, as well as the FID peak areas, are contrasted separately. The initial development of a method for distinguishing condensed ring aromatic systems from alkyl substituted aromatic systems was accomplished. N,2,4,6-tetrachloroacetanilide was reacted with standards and with an aromatic fraction of shale oil. Mass spectral analysis and specific element detection (for carbon and chlorine), with a microwave emission detector (MED), were performed on the reaction products. Chlorination of alkyl groups occurred. The formation of olefins was documented, contrary to literature reports. Gas and liquid chromatographic methods for several organoarsenic compounds were developed. The stability of some pentacoordinate organoarsenic compounds was investigated by thermogravimetry. The concentration of arsenic in boiling point distillation cuts of shale oil and in concentrated fractions from liquid chromatographic class separations were obtained by x-ray fluorescence and by inductively coupled plasma with hydride generation. The analysis of shale oil on the GC-MED system was attempted and although a detection limit of 0.4 picograms/second was obtained on the arsenic 228.8 nanometer line no arsenic species could be identified.

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Atomic plasma emission spectroscopy provides a versatile element-specific detection tool for gas chromatography. Element selective detection has many applications in the field of petrochemical, environmental, pesticide and industrial analysis. It affords the analysis of compounds of interest in relatively complex samples, as the element selective response can flag compounds containing specific elements even if such compounds are co-eluting with other compounds. This dissertation research has been focused on the applications of GC-AED coupled with sample derivatization techniques for the analysis of complex petrochemical and industrial samples. Research centers of three different projects. Analysis of chlorofluorocarbons (CFC) was done in order to investigate the capability of the atomic emission detection system to produce compound independent elemental specific response. Atomic emission detection (GC-AED) can perform qualitative as well as quantitative analysis of unknown CFCs using only one available standard. Elemental response ratio (empirical formula) information provides the basis for qualitative analysis whereas individual elemental response forms the basis for quantitative analysis. Investigations concerning AED's compound independent element response were undertaken. It was observed that the reference standard and the sample should be similar with respect to molecular structure, elemental composition and concentration. The determination of olefins in commercial gasolines is critical as it determines the overall quality of gasoline fuel. Since gasoline samples are very complex it is difficult to get an olefin chromatographic profile using conventional single capillary gas chromatography coupled to flame ionization or mass spectroscopic detectors. However, analysis of olefins is possible by GC-AED if a hetero-atom tag is selectively introduced on the olefin molecules. The olefins were selectively and quantitatively brominated without affecting the aromatic and saturated hydrocarbon components of the gasoline. By observing the bromine emission signal by the atomic emission detector, the olefin chromatographic profile for a gasoline sample was obtained, thereby avoiding the interference from the coeluting hydrocarbons. The optimization of the bromination reaction was carried out using a known hydrocarbon mixture that typified the gasoline components. The determination of dicarboxylic acids in water samples has a very broad applicability as organic acids occur in wide variety of samples. Prior to gas chromatography the diacids were esterified by using pentafluorobenzyl bromide as an esterifying agent and tetrahexylammonium hydrogen sulfate as phase transfer catalyst. Esterfication is a single step process that yields diester molecules that contain ten fluorine atoms. By observing the fluorine emission signal from the atomic emission detector one can determine the amount of each diester. The optimization of the esterification reaction was carried out using a known diacid mixture, and unknown water samples were analyzed.

Escoamentos multifásicos estão presentes em diversas aplicações industriais, principalmente na indústria do petróleo. Um dos casos de aplicação, objeto de estudo desse trabalho, é a determinação da produção de poços de petróleo através de válvulas choke. É apresentada uma revisão dos efeitos físicos e do equacionamento adotado pelos principais modelos multifásicos existentes para tais válvulas. Um estudo de sensibilidade de tais efeitos físicos é realizado, analisando as possíveis alternativas para a diferença de velocidade entre as fases, o mecanismo adotado para a troca de calor entre as fases, a influência da energia cinética a montante da válvula, a influência da área efetiva da garganta e a metodologia de cálculo da recuperação de pressão a jusante da válvula. Conclui-se que dos diversos fatores que influenciam no cálculo da vazão mássica e da condição crítica, a área efetiva da garganta é um parâmetro importante e que é necessário uma maior investigação de como determinar tal parâmetro. / Multiphase flow are present in many industrial applications, mainly at the petroleum industry. One of these application cases, aim of this work study, is to determine a petroleum well production by the choke valves. It is presented a revision of the physical effects and for the adopted equation by the main existing multiphase models for such valves. A sensibility study of such physical effects is performed, analyzing the possible alternatives for the phases velocities difference, the adopted mechanism for the heat transfer between the phases, the upstream kinetic energy influence, the throat effective area influencie and the calculation methodology adopted for the valve downstream pressure recover. It is concluded that from many factors that influence in the mass flow and critical condition calculation, the throat effective area is a important parameter and it is necessary a deeper investigation in how to determine such parameter.

Escoamentos multifásicos estão presentes em diversas aplicações industriais, principalmente na indústria do petróleo. Um dos casos de aplicação, objeto de estudo desse trabalho, é a determinação da produção de poços de petróleo através de válvulas choke. É apresentada uma revisão dos efeitos físicos e do equacionamento adotado pelos principais modelos multifásicos existentes para tais válvulas. Um estudo de sensibilidade de tais efeitos físicos é realizado, analisando as possíveis alternativas para a diferença de velocidade entre as fases, o mecanismo adotado para a troca de calor entre as fases, a influência da energia cinética a montante da válvula, a influência da área efetiva da garganta e a metodologia de cálculo da recuperação de pressão a jusante da válvula. Conclui-se que dos diversos fatores que influenciam no cálculo da vazão mássica e da condição crítica, a área efetiva da garganta é um parâmetro importante e que é necessário uma maior investigação de como determinar tal parâmetro. / Multiphase flow are present in many industrial applications, mainly at the petroleum industry. One of these application cases, aim of this work study, is to determine a petroleum well production by the choke valves. It is presented a revision of the physical effects and for the adopted equation by the main existing multiphase models for such valves. A sensibility study of such physical effects is performed, analyzing the possible alternatives for the phases velocities difference, the adopted mechanism for the heat transfer between the phases, the upstream kinetic energy influence, the throat effective area influencie and the calculation methodology adopted for the valve downstream pressure recover. It is concluded that from many factors that influence in the mass flow and critical condition calculation, the throat effective area is a important parameter and it is necessary a deeper investigation in how to determine such parameter.

No description available.

No description available.