Productivity Formulas for a Partially Penetrating Vertical Well in a Circular Cylinder Drainage Volume

Taking a partially penetrating vertical well as a uniform line sink in three-dimensional space, by developing necessary mathematical analysis, this paper presents steady state productivity formulas for an off-center partially penetrating vertical well in a circular cylinder drainage volume with constant pressure at outer boundary. This paper also gives formulas for calculating the pseudo-skin factor due to partial penetration. If top and bottom reservoir boundaries are impermeable, the radius of the cylindrical system and off-center distance appears in the productivity formulas. If the reservoir has a gas cap or bottom water, the effects of the radius and off-center distance on productivity can be ignored. It is concluded that, for a partially penetrating vertical well, different productivity equations should be used under different reservoir boundary conditions

Interpretacion de pruebas de inyeccion en yacimientos naturalmente fracturados

Este estudio presenta un nuevo método para determinar la transmisibilidad en yacimientos naturalmente fracturados usando el análisis del flujo radial en pruebas de calibración. El método se basa en el análisis del comportamiento de la derivada de la presión con el tiempo. El objetivo es simplificar y facilitar la identificación del flujo radial y la “gargantaâ€� característica que se observa en la derivada cuando se tienen yacimientos naturalmente fracturados. El método propuesto no requiere el conocimiento previo de la presión de yacimiento. Un grafico logarítmico es usado para determinar la permeabilidad, la presión promedio, el almacenamiento y el coeficiente que relaciona las permeabilidades s de la matriz y de las fracturas en el yacimiento

Improving the accuracy of determining the character saturation reservoirs on the results of log interpretation in the oil field "K"(Tomsk region)

Log interpretation has revealed a number of factors that have a significant impact on the determination of reservoir fluid content (oil saturation factor). The presented research paper is focused on the analysis of petrophysical properties of reservoir fluids considering laboratory studies of core samples. Based on core sample analysis, data of laboratory studies have been correlated to estimates of radioactive logging and high-frequency induction logging. To determine the oil saturation factor a method which considers the effect of mixed clay on reservoir fluid saturation has been proposed

Petrophysics : theory and practice of measuring reservoir rock and fluid transport properties

This new edition includes updated case studies, examples and experiments as well as a new chapter on modeling and simulations. It also includes recent advances in wireline logging interpretation methods, effective media models, inversion of resistivity log measurements, dipole acoustic shear and Stoneley wave techniques, Biot-Gassmann models and MRI. Presenting concepts, theories, and lab procedures related to porous rocks and gases, hydrocarbon liquids, and aqueous solutions, this third edition reference (the first was published in 1996, and the second in 2003) has been updated and expanded. Two new chapters on reservoir characterization and on basic well-log interpretation offer the basic introductory material intended as a foundation for further study of the topics. This book introduces mineralogy and petroleum geology before covering porosity and permeability, formation resistivity and water saturation, capillary pressure, wettability, applications of Darcy’s Law, naturally fractured reservoirs, and the effect of stress on reservoir rock properties, among other topics

Pseudo-Steady-State Productivity Formula for a Partially Penetrating Vertical Well in a Box-Shaped Reservoir

For a bounded reservoir with no flow boundaries, the pseudo-steady-state flow regime is common at long-producing times. Taking a partially penetrating well as a uniform line sink in three dimensional space, by the orthogonal decomposition of Dirac function and using Green's function to three-dimensional Laplace equation with homogeneous Neumann boundary condition, this paper presents step-by-step derivations of a pseudo-steady-state productivity formula for a partially penetrating vertical well arbitrarily located in a closed anisotropic box-shaped drainage volume. A formula for calculating pseudo skin factor due to partial penetration is derived in detailed steps. A convenient expression is presented for calculating the shape factor of an isotropic rectangle reservoir with a single fully penetrating vertical well, for arbitrary aspect ratio of the rectangle, and for arbitrary position of the well within the rectangle

Evaluación De La Eficiencia De Solventes En La Remoción Del Banco De Comdensado

This work describes experimental design and tests performed to simulate gas condensate reservoir conditions below dew point in the laboratory using three different compositions of synthetic gas condensate. Methanol, propanol and methylene chloride are the solvents used to remove the condensate banking and improve the gas effective permeability near to the wellbore. Solvents are injected in Berea sandstone rock with similar petrophysical properties in order to compare the efficiency at removing the condensate banking. It was observed that all of the solvents improved the gas effective permeability after removing banking condensate; however, methanol was the more efficient solvent to remove it while methylene chloride had the lowest values of gas effective permeability after removing the banking condensate.Este estudio describe el montaje experimental y las pruebas realizadas en el laboratorio para simular las condiciones de un yacimiento de gas condensado por debajo del punto de burbuja usando tres diferentes composiciones sintéticas de gas condensado. Metanol, Propanol y cloruro de metileno son los solventes usados para remover el banco de condensado y mejorar la permeabilidad efectiva al gas en la cara del núcleo. Ellos son inyectados en areniscas Berea con propiedades petrofísicas similares con el fin de comparar el grado de eficiencia en la remoción del banco de condensado. Los experimentos muestran que los tres solventes mejoraron la permeabilidad efectiva al gas después de remover el banco de condensado; sin embargo el metanol fue el solvente más eficiente para remover el banco de condensado, mientras el cloruro de metileno mostró los valores más bajos de permeabilidad efectiva al gas indicando menor eficiencia en la remoción el banco de condensado

Pseudo-Steady-State Productivity Formula for a Partially Penetrating Vertical Well in a Box-Shaped Reservoir

For a bounded reservoir with no flow boundaries, the pseudo-steady-state flow regime is common at long-producing times. Taking a partially penetrating well as a uniform line sink in three dimensional space, by the orthogonal decomposition of Dirac function and using Green's function to three-dimensional Laplace equation with homogeneous Neumann boundary condition, this paper presents step-by-step derivations of a pseudo-steady-state productivity formula for a partially penetrating vertical well arbitrarily located in a closed anisotropic box-shaped drainage volume. A formula for calculating pseudo skin factor due to partial penetration is derived in detailed steps. A convenient expression is presented for calculating the shape factor of an isotropic rectangle reservoir with a single fully penetrating vertical well, for arbitrary aspect ratio of the rectangle, and for arbitrary position of the well within the rectangle