The ultimate success of carbon capture and storage project will be ensured only when there is a safe and effective permanent storage of CO₂ for a significant amount of time without any leakages. Credible monitoring and verification is one of the most important aspects of CO₂ sequestration. Accurate reservoir characterization is an important pre-requisite for the design, operation and economic success of processes like CO₂ sequestration. The techniques available include geophysical and geochemical monitoring as well as numerical simulations using models replicating the field. In conducting the numerical simulations, it is required to assess the reservoir heterogeneity correctly. Previous work has shown that the injection data from wells can be utilized for developing models during CO₂ sequestration to understand the spatial distribution of heterogeneities in the formation. In this research, we first understand and examine the information contained in the injection data for a wide range of reservoir models demonstrating different kinds of heterogeneities and rate fluctuations. We will confirm that the reservoir heterogeneities have an imprint on the injection pressure response and they influence CO₂ plume migration significantly. Later we show that the effect of high or low permeability features along with rate fluctuations can provide considerable information about permeability heterogeneity in the reservoir. The applicability of this observation is made using field data from In-Salah gas field from central Algeria. Thus we demonstrate the feasibility of developing an inexpensive method of modeling reservoir heterogeneity by employing readily available measurements of injection pressure and rate to track CO₂ migration. Later we describe method to find out what characteristics of the reservoir heterogeneities can be quantified using injection data (pressure and rate). The injection pressure response during CO₂ sequestration will depend strongly on reservoir, fluid and well properties. A 3-D analytical model with infinite acting boundary is developed in CMG-GEM. Compositional reservoir simulation results from CMG-GEM simulator will be obtained and combined with pressure transient analysis and optimization algorithm for the prediction of reservoir parameters. In case of multiple injection wells in a heterogeneous formation, the analysis yield spatial variations in reservoir parameter groups like transmissibility (kh), permeability to porosity ratio ([kappa]/[phi]) in different part of the reservoir. These parameter groups can subsequently be used to constrain models of reservoir thickness, permeability and porosity. Thus, we imply that multiple reservoir attributes affect migration of CO₂ plume and there is uncertainty associated with the estimation of these attributes. We present an approach to resolve some of that uncertainty using information extracted from injection well response. / text

Naturally fractured reservoirs (NFR) represent an important percentage of the worldwide hydrocarbon reserves and production. Reservoir simulation is a fundamental technique in characterizing this type of reservoir. Fracture properties are often not available due to difficulty to characterize the fracture system. On the other hand, well test analysis is a well known and widely applied reservoir characterization technique. Well testing in NFR provides two characteristic parameters, storativity ratio and interporosity flow coefficient. The storativity ratio is related to fracture porosity. The interporosity flow coefficient can be linked to shape factor, which is a function of fracture spacing. The purpose of this work is to investigate the feasibility of estimating fracture porosity and fracture spacing from single well test analysis and to evaluate the use of these two parameters in dual porosity simulation models. The following assumptions were considered for this research: 1) fracture compressibility is equal to matrix compressibility; 2) no wellbore storage and skin effects are present; 3) pressure response is in pseudo-steady state; and 4) there is single phase flow. Various simulation models were run and build up pressure data from a producer well was extracted. Well test analysis was performed and the result was compared to the simulation input data. The results indicate that the storativity ratio provides a good estimation of the magnitude of fracture porosity. The interporosity flow coefficient also provides a reasonable estimate of the magnitude of the shape factor, assuming that matrix permeability is a known parameter. In addition, pressure tests must exhibit all three flow regimes that characterizes pressure response in NFR in order to obtain reliable estimations of fracture porosity and shape factor.

The application of carbon-dioxide injection for enhanced oil recovery and/or sequestration purposes has gained impetus in the last decade. It is known that well test analysis plays a crucial role on getting information about reservoir properties, boundary conditions, etc. Although there are some studies related to the well test analysis in the fractured reservoirs, most of them are not focused on the carbon dioxide injection into the reservoir. Naturally fractured reservoirs (NFR) represent an important percentage of the worldwide hydrocarbon reserves and current production. Reservoir simulation is a fundamental technique in characterizing this type of reservoirs. Fracture properties are often not clear due to difficulty to characterize the fracture systems. On the other hand, well test analysis is a well known and widely applied reservoir characterization technique. Well testing in NFR provides two significant characteristic parameters, storativity ratio (&omega / ) and interporosity flow coefficient (&lambda / ). The storativity ratio is related to fracture porosity. The interporosity flow coefficient can be linked to the shape factor which is a function of fracture spacing. In this study, the effects of fracture and fluid flow factors (geometry, orientation and flow properties) on pressure and pressure derivative behavior are studied by applying a reservoir simulation model. Model is utilized mainly for the observation of multiphase flow effects in CO2 flooded fractured reservoirs. Several runs are conducted for various ranges of the aforementioned properties in the CO2 flooded reservoir. Results of well test analysis are compared to the input data of simulation models on a parameter basis.

This work studied the productivity evaluation and well test analysis of horizontal wells. The major components of this work consist of a 3D coupled reservoir/wellbore model, a productivity evaluation, a deconvolution technique, and a nonlinear regression technique improving horizontal well test interpretation. A 3D coupled reservoir/wellbore model was developed using the boundary element method for realistic description of the performance behavior of horizontal wells. The model is able to flexibly handle multiple types of inner and outer boundary conditions, and can accurately simulate transient tests and long-term production of horizontal wells. Thus, it can serve as a powerful tool in productivity evaluation and analysis of well tests for horizontal wells. Uncertainty of productivity prediction was preliminarily explored. It was demonstrated that the productivity estimates can be distributed in a broad range because of the uncertainties of reservoir/well parameters. A new deconvolution method based on a fast-Fourier-transform algorithm is presented. This new technique can denoise "noisy" pressure and rate data, and can deconvolve pressure drawdown and buildup test data distorted by wellbore storage. For cases with no rate measurements, a "blind" deconvolution method was developed to restore the pressure response free of wellbore storage distortion, and to detect the afterflow/unloading rate function using Fourier analysis of the observed pressure data. This new deconvolution method can unveil the early time behavior of a reservoir system masked by variable-wellbore-storage distortion, and thus provides a powerful tool to improve pressure transient test interpretation. The applicability of the method is demonstrated with a variety of synthetic and actual field cases for both oil and gas wells. A practical nonlinear regression technique for analysis of horizontal well testing is presented. This technique can provide accurate and reliable estimation of well-reservoir parameters if the downhole flow rate data are available. In the situation without flow rate measurement, reasonably reliable parameter estimation can be achieved by using the detected flow rate from blind deconvolution. It has the advantages of eliminating the need for estimation of the wellbore storage coefficient and providing reasonable estimates of effective wellbore length. This technique provides a practical tool for enhancement of horizontal well test interpretation, and its practical significance is illustrated by synthetic and actual field cases.

Orientador: Rosângela Barros Zanoni Lopes Moreno / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-21T10:32:47Z (GMT). No. of bitstreams: 1 Sousa_BrunoRangelde_M.pdf: 2665889 bytes, checksum: d124b91d0b604845255264f303b44b22 (MD5) Previous issue date: 2012 / Resumo: Apresenta-se nesta dissertação um estudo sobre o comportamento transitório da pressão em poços inclinados submetidos a teste de poço. A partir de referências disponíveis na literatura, são apresentadas soluções analíticas e semi-analíticas, onde é adotado o modelo de escoamento uniforme como condição de contorno no poço. Neste estudo é considerado um reservatório de extensão radial infinita com limites verticais impermeáveis. A partir da solução analítica são apresentadas curvas típicas para diferentes ângulos de inclinação do poço e espessura adimensional da formação. As análises das curvas típicas indicam três regimes de escoamento: radial inicial, radial de transição e radial infinito, onde, no melhor conhecimento deste autor, o regime de escoamento radial de transição é introduzido nesta dissertação. A partir da solução semi-analítica, derivada no domínio de Laplace, são desenvolvidas assíntotas para tempo-curto e tempo-longo. Esta dissertação ainda apresenta um procedimento alternativo para interpretar os dados transitórios da pressão em poços inclinados. O desenvolvimento deste procedimento foi baseado na técnica TDS (Tiab's Direct Synthesis), onde é possível interpretar os dados de pressão através de uma análise direta da curva de derivada. As soluções aqui apresentadas fornecem uma alternativa acessível à completa modelagem numérica - utilizada em pacotes comerciais para interpretação de teste de pressão / Abstract: A study on the transient pressure behavior it is presented in this dissertation for slanted well test analysis. From references available in the literature, analytical and semi-analytical solutions are presented for the uniform flow boundary condition at the well. In this study is considered an infinite radial extent reservoir limited with vertical impermeable boundaries. Type curves are presented for different slant angles of the well and dimensionless formation thickness. From the analysis of type curves are observed three flow regimes: early time radial flow, transition radial flow and late time infinite-acting radial flow. For the best knowledge of the author, the transition radial flow regime is introduced in this dissertation for the first time. From the semi-analytical solution, derived in the Laplace domain, asymptotic solutions are developed for early-time and late-time. It is also presented an alternative procedure for interpreting pressure transient data in slanted wells. The development of this procedure was based on the TDS (Tiab's Direct Synthesis) technique, by where it is possible to interpret the pressure data through a direct analysis of the derived curve. The solutions presented here provide a feasible alternative to full numerical modeling - used in commercial packages for the interpretation of pressure tests / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Kern der Arbeit bildete die Entwicklung einer Fluxmeter-Passivsammlereinheit für hydrophobe organische Substanzen im Grundwasser kontaminierter Standorte sowie deren Testung im Feld. Ferner kamen Keramik-Dosimeter unter identischen Feldbedingungen zum Einsatz. Die Ergebnisse der beiden passiven Sammelsysteme wurden mit herkömmlicher Grundwasserprobennahmetechnik mithilfe von Unterwassermotorpumpen verglichen und bewertet. Grundlage für den Einsatz der Passivsammlereinheit als „mass flux meter“ bildete die Kenntnis über den Volumenstrom im Bohrloch und den reduzierten Volumenstrom in der Passivsammlereinheit und andererseits über die räumliche Verteilung der hydraulischen Durchlässigkeit und der daraus resul¬tierenden heterogenen Geschwindigkeitsverteilung bzw. der Volumenströme über so genannte Kontroll¬ebenen bzw. Teilbilanzräume. Anhand numerischer Modelluntersuchungen konnten der Filterwiderstand der Passivsammlereinheit und die Strömungsverteilung in Modellkontrollebenen und im Feld näherungsweise bestimmt werden. Die Bestimmung des Volumenstromes des untersuchten Standortes wurde zum einen mithilfe von numerischen Modelluntersuchungen an stochastisch generierten quasi-3-dimensionalen Modellen mit hydro¬dynamischen Randbedingungen und kF-Wertverteilungen aus dem Feld und zum anderen mithilfe von Einbohrlochverfahren durchgeführt. Als Einbohrlochverfahren kamen zum einen ein optisches Kolloid-Logging (Grundwasserfluss-Visualisierungssystem) und zum anderen ein modifiziertes Fluidlogging-Verfahren mit Hilfe eines Salztracers zum Einsatz.

Det finns idag behov av att ta fram information om hur vatten flödar i marken. För att undersöka detta brukar det installeras grundvattenrör. Grundvattenrör används oftast i syfte att bevaka grundvattennivåer i marken men kan även användas för att utföra hydrauliska tester vars syfte är att skatta jordens hydrauliska egenskaper. Det är då framförallt den hydrauliska konduktiviteten som söks. Kunskap om markens hydrauliska konduktivitet är bland annat viktig för modellering av grundvattenflöden och beräkning av föroreningsspridning. Genom åren har det utvecklats ett antal hydrauliska tester för att ta fram hydrauliska egenskaper i jorden. Från de ursprungliga testerna med pumprör och observationsrör (interferenstester) har det tillkommit metoder för att genomföra tester i enskilda grundvattenrör. Idag kan bland annat pumptest och slugtest genomföras för att skatta hydrauliska egenskaper i enskilda grundvattenrör. Examensarbetet har undersökt olika hydrauliska tester som genomförs i enskilt grundvattenrör. Testerna har varit pumptest, injektionstest, slugtest med solid slug, slugtest med vatten och stigningsmätning. Testerna har genomförts i 11 olika grundvattenrör. Grundvattenrören har varit placerade i olika jordarter och akvifertyper. Alla tester har gjorts i alla rör för att kunna göra en jämförelse mellan testerna. Resultat från testerna visar att det föreligger en variation i skattade hydrauliska egenskaper när en jämförelse gjordes mellan alla slugtester och alla pumptester. Pumptesterna gav generellt en mindre variation mellan test och modellösning och visar sig därför mer oberoende av testtyp och val av modellösning. Slugtesterna visade skillnad i skattad hydraulisk konduktivitet beroende på modellösning. Modellösningarna Hyder mfl. (1994)/KGS och Dougherty-Babu (1984) för slugtest gav en högre skattning hydraulisk konduktivitet än pumptesterna medan modellösningen Bouwer-Rice (1976) gav en lägre skattning av hydraulisk konduktivitet än pumptesterna. Testerna skiljer sig åt när de genomförs i olika jordarter. I lågkonduktiva jordarter är det svårt att genomföra olika typer av pumptest då dessa är påverkade av brunnsmagasin och det krävs att pumpflödet är tillräckligt lågt för att grundvattenröret inte ska torrläggas eller svämma över. Därför är det rekommenderat att utföra slugtest i lågkonduktiva jordarter. I högkonduktiva jordarter är det rekommenderat att göra pumptester då slugtester genererar färre mätpunkter och kan därför leda till fel i modelleringen. / There is a need today to gain information on how water moves in the ground. Groundwater pipes are therefore installed to monitor the groundwater levels. These groundwater pipes can however be used to perform hydraulic tests to obtain information regarding hydraulic properties of the soil. Hydraulic tests are usually performed to investigate the water flow in the soil. This water flow is called hydraulic conductivity. Information on hydraulic conductivity is, for example, essential in modeling of pollutant transport. Several types of hydraulic tests have been developed throughout history in the purpose to investigate hydraulic properties in the soil. The original tests involved pumping tests where one pipe was pumped while an adjacent pipe was used to monitor water level changes. From these original pumping tests there has been a development where the methods can be applied in a single groundwater pipe. Typical single-well tests used today are pumping tests and slug tests. This thesis has investigated and evaluated different hydraulic test performed in single groundwater pipes. Two types of pumping test have been performed: pumping test with constant flow, where the water is pumped out from the pipe, and injection test where water is pumped into the pipe with a constant flow. Three types of slug test have been performed: slug test using a solid slug, slug test using water and rising head test. Slug test is a test where the water level in the pipe is rapidly lowered or raised. The time it takes for the water to return to the initial water level is measured and used to calculate the hydraulic conductivity of the soil. The tests have been performed in 11 different groundwater monitoring pipes. The groundwater pipes were situated in different types of soil and aquifers. All the tests were performed in all the pipes to be able to compare them. Different model solutions were used to analyze the measured data from the hydraulic tests. The results showed variation in estimated hydraulic conductivity when the average hydraulic conductivity of pumping tests and slug tests were compared. The different types of pumping tests had on average a small difference in hydraulic conductivity and the results were on average independent of model solution used. Depending on the model solution there was a difference in hydraulic conductivity for the slug tests. The model solutions of Hyder et al (1994)/KGS and Dougherty-Babu (1984) for slug test estimated over-all a higher hydraulic conductivity than the pumping tests while the model solution of Bouwer-Rice (1976) estimated over-all a lower hydraulic conductivity than the pumping tests. The results and performance of the tests behaved differently depending on the type of soil. It was difficult to perform pumping and injection tests in low conductivity soils due to well-bore storage in the groundwater pipe. It is therefore recommended to perform slug tests in low conductivity soils and pumping tests in high conductivity soil because slug tests generates fewer measurements than pumping tests and can cause errors in the modeling.

Kern der Arbeit bildete die Entwicklung einer Fluxmeter-Passivsammlereinheit für hydrophobe organische Substanzen im Grundwasser kontaminierter Standorte sowie deren Testung im Feld. Ferner kamen Keramik-Dosimeter unter identischen Feldbedingungen zum Einsatz. Die Ergebnisse der beiden passiven Sammelsysteme wurden mit herkömmlicher Grundwasserprobennahmetechnik mithilfe von Unterwassermotorpumpen verglichen und bewertet. Grundlage für den Einsatz der Passivsammlereinheit als „mass flux meter“ bildete die Kenntnis über den Volumenstrom im Bohrloch und den reduzierten Volumenstrom in der Passivsammlereinheit und andererseits über die räumliche Verteilung der hydraulischen Durchlässigkeit und der daraus resul¬tierenden heterogenen Geschwindigkeitsverteilung bzw. der Volumenströme über so genannte Kontroll¬ebenen bzw. Teilbilanzräume. Anhand numerischer Modelluntersuchungen konnten der Filterwiderstand der Passivsammlereinheit und die Strömungsverteilung in Modellkontrollebenen und im Feld näherungsweise bestimmt werden. Die Bestimmung des Volumenstromes des untersuchten Standortes wurde zum einen mithilfe von numerischen Modelluntersuchungen an stochastisch generierten quasi-3-dimensionalen Modellen mit hydro¬dynamischen Randbedingungen und kF-Wertverteilungen aus dem Feld und zum anderen mithilfe von Einbohrlochverfahren durchgeführt. Als Einbohrlochverfahren kamen zum einen ein optisches Kolloid-Logging (Grundwasserfluss-Visualisierungssystem) und zum anderen ein modifiziertes Fluidlogging-Verfahren mit Hilfe eines Salztracers zum Einsatz.

Dans les puits de production d’eau, de pétrole, de gaz et de chaleur géothermique, ou dans les puits d’accès à un stockage d’hydrocarbures, il est précieux de connaître la perméabilité de la formation ou de sa couverture en fonction de la profondeur, soit pour améliorer le modèle de réservoir, soit pour choisir les zones dans lesquelles procéder à des opérations spéciales.On propose une technique qui consiste à balayer la hauteur du découvert par une interface entre deux liquides de viscosités très contrastées. Le débit total qui pénètre la formation à chaque instant est ainsi une fonction de la position de l’interface et de l’historique des pressions dans le puits. On doit alors résoudre un problème inverse : rechercher la perméabilité fonction de la profondeur à partir de l’historique des débits dans le temps. Dans la pratique, le puits est équipé d’un tube central. Le balayage est effectué par injection d’un liquide à pression d’entrée constante dans le tube central et soutirage d’un autre liquide par l’espace annulaire. On mesure les débits d’injection et de soutirage dont la différence est le débit qui entre dans la formation.Pour valider et améliorer cette technique, on a d’abord utilisé une maquette simulant un découvert multi-couches disponible au LMS. On a exploité aussi des essais en place réalisés dans la couverture peu perméable d’un stockage souterrain de gaz. Dans ces essais, un liquide visqueux placé dans le découvert était déplacé par un liquide moins visqueux (méthode dite « opening »). Les couches plus perméables étaient correctement identifiées (Manivannan et al. 2017), mais une estimation quantitative était un défi en raison des phénomènes transitoires qui affectent le voisinage immédiat des puits. De plus, le rayon investigué dans le massif était petit.La thèse a relevé ces défis en proposant un essai légèrement différent et une nouvelle technique d’interprétation. Les essais avec une maquette modifiée ont montré la supériorité d’une méthode « closing » dans laquelle le puits est d’abord rempli du liquide le moins visqueux. On ménage une période de stabilisation avant l’injection du liquide visqueux pour réduire les effets transitoires ; elle permet aussi d’estimer la perméabilité moyenne et l’influence de la zone endommagée à la paroi (le « skin »).Puis on conduit l’essai proprement dit. L’historique des débits mesurés en tête de puits constitue le profil d’injection dont on déduit le profil de perméabilité.. Cette estimation suppose un écoulement monophasique dans chaque couche et la même « skin » pour toute la formation. Les incertitudes principales portent sur les pressions de formation et les variations possibles du « skin ». Elles sont estimées au moyen d’un calcul analytique. On a vérifié sur la maquette que les profils de perméabilité estimés présentent une bonne concordance avec les perméabilités mesurées avant les essais.On a réalisé un essai sur un sondage de 1750 m de long atteignant une couche de sel dont on a correctement estimé la perméabilité moyenne pendant la période de stabilisation. Toutefois elle était si faible (4.0E-21 m²) que l’utilisation de deux fluides n’a pas permis de faire une différence entre les diverses parties du puits. / In wells producing water, oil, gas or geothermal energy, or in access wells to hydrocarbon storage, it is critical to evaluate the permeability of the formation as a function of depth, to improve the reservoir model, and also to identify the zones where additional investigation or special completions are especially useful.A new technique is proposed, consisting of scanning the open hole (uncased section of the wellbore) with an interface between two fluids with a large viscosity contrast. The injection rate into the formation depends on interface location and well pressure history. An inverse problem should be solved: estimate permeability as a function of depth from the evolution of flow rates with time. The wells are usually equipped with a central tube. The scanning is done by injecting a liquid in the central tube at constant wellhead pressure. Injection and withdrawal rates are measured at the wellhead; the difference between these two rates is the formation injection rate.To validate and improve this technique, we used a laboratory model mimicking a multi-layer formation, already available at LMS. We also made use of in-situ tests performed on an ultra-low permeable cap rock above an underground gas storage reservoir. In these tests, a viscous fluid contained in the open hole was displaced by a less-viscous fluid (a method called opening WTLog). The more permeable layers were correctly identified (Manivannan et al. 2017), but a quantitative estimation was challenging due to transient phenomena in the vicinity of the wellbore (near-wellbore zone). In addition, the investigation radius was small.These challenges are addressed by proposing a slightly modified test procedure and a new interpretation workflow. Laboratory tests with a modified test setup showed the advantages of the ‘closing’ method in which the well is filled with a less-viscous fluid at the start of the test. We also added a stabilization period before the injection of viscous fluid to minimize the transient effects; this period is also used to estimate the average permeability of the open hole and the effect of near-wellbore damage (skin).Then the test proper is performed (closing WTLog). The injection profile of the less-viscous fluid is computed from the wellhead flow rate history. A permeability profile is estimated from the injection profile. The permeability estimation considers a monophasic flow in each layer and the same skin value for all the formation layers. Major uncertainties in the permeability estimates are caused by formation pressures and heterogeneities in skin values; they are estimated using an analytical formula. We have verified on the laboratory setup that the estimated permeability profiles are well correlated to the permeabilities measured before the tests.An attempt was made to perform a WTLog in a 1750-m long wellbore opening in a salt formation. The first phase was successful and the average permeability was correctly assessed. However, this permeability was so small (4.0E-21 m² or 4 nD) that the gauges and the flowmeters were not accurate enough to allow a clear distinction between the permeabilities of the various parts of the open hole.

[pt] Tradicionalmente, os testes de formação em poços de petróleo buscam caracterizar o campo de permeabilidades a partir da interpretação dos transientes de pressão (PTA) nos períodos de fluxo e estática baseados em modelos isotérmicos de escoamento em meios porosos. Com o avanço da instrumentação dos testes, registros mais precisos de temperatura passaram a estar disponíveis e fomentaram a pesquisa baseada em modelos não isotérmicos que possibilitaram a análise a partir dos transientes de temperatura (TTA). Além da caracterização de parâmetros do reservatório como permeabilidade e porosidade com a interpretação dos transientes de temperatura, os dados de pressão obtidos a partir de um modelo não isotérmico representa de forma mais fidedigna o fenômeno físico sobretudo quando os testes são submetidos a maiores diferenciais de pressão. Este trabalho consiste no desenvolvimento de um simulador para teste de formação que considera a modelagem não isotérmica de reservatório unidimensional radial acoplado a um poço produtor e na utilização deste simulador, associado a métodos de otimização multivariável, para resolução do problema inverso da caracterização de parâmetros do reservatório. Alguns métodos de otimização foram testados e o algoritmo do Simplex de Nelder-Mead apresentou melhor eficácia. Foram estabelecidos três tipos de problemas e utilizados em três casos hipotéticos considerando inclusive a imposição artificial de ruídos nos sinais de pressão e temperatura utilizados para resolução do problema inverso. / [en] Traditionally, oil well formation tests aim to characterize the reservoir permeability field from pressure transient analysis (PTA) of drawdown and build up based on isothermal flow models in porous media. With the advancement of well test instrumentation, more accurate temperature records became available and have encouraged researches based on non-isothermal models that made possible the temperature transient analysis (TTA). In addition to the characterization of reservoir parameters such as permeability and porosity by TTA, the pressure data obtained from a non-isothermal model represent better the physical phenomenon, especially when the tests are subjected to greater drawdowns. This work consists in the development of a simulator for formation test that considers non-isothermal modeling of a unidimensional radial reservoir coupled to a production well and in the use of this simulator, associated with multivariable optimization methods, to solve the inverse problem of reservoir parameters characterization. Some optimization methods were tested and the Nelder-Mead Simplex algorithm presented better efficiency. Three types of problems were established and used in three hypothetical cases, including artificially imposed noise in pressure and temperature signals used to solve the inverse problem.