Evaluación de la recuperación mejorada de petróleo con CO2 en formaciones de baja permeabilidad con fracturas de geometría compleja

Descargue el texto completo en el repositorio institucional de la University of Texas at Austin: http://hdl.handle.net/2152/39374Analiza la eficacia de la inyección de CO₂ como método de recuperación mejorada en formaciones de baja permeabilidad. Se utiliza el diseño de experimentos y la superficie de respuesta para realizar estudios de sensibilidad a cuatro parámetros: la permeabilidad de la matriz, el número de pozos, el patrón del pozo y la longitud de ala de fractura. Se introduce una metodología más eficiente de modelado, EDFM, para modelar y simular explícitamente geometrías de fractura complejas. También se investigaron los efectos de las geometrías de fracturas complejas en el rendimiento de esquemas de inyección continua y Huff-n-Puff de CO₂, así como el efecto de las fracturas naturales. El análisis de la efectividad de EOR con CO₂ confirma que el modelado apropiado de la geometría de las fracturas complejas juega un papel crítico en la estimación de la recuperación incremental de petróleo. Este estudio proporciona nuevos conocimientos para la estimación de la recuperación mejorada, el impacto de la permeabilidad, las fracturas hidráulicas complejas y las fracturas naturales en el rendimiento del EOR con CO₂, en reservorios de petróleo de baja permeabilidad, así como en la determinación del diseño óptimo de inyección-producción para maximizar el factor de recuperación.In this study, the CO₂-EOR effectiveness is simulated and analyzed by comparing the Huff-n-Puff and the continuous injection scenarios. The effect of matrix permeability on the comparison of well performance of these two scenarios was investigated. Subsequently, Design of Experiment and Response Surface Methodology is used to perform sensitivity studies with four uncertain parameters including matrix permeability, number of wells, well pattern, and fracture half-length to determine the best injection approach. In addition, an efficient methodology of embedded discrete fracture model (EDFM) is introduced to explicitly model complex fracture geometries. The effects of complex fracture geometries on well performance of CO₂ Huff-n-Puff and CO₂ continuous injection were also investigated as well as the effect of natural fractures. The analysis of the CO₂-EOR effectiveness confirms that the appropriate modelling of the complex fractures geometry plays a critical role in estimation of the incremental oil recovery. This study provides new insights into a better understanding of the impacts of reservoir permeability, complex hydraulic fractures and natural fractures on well performance during CO₂-EOR process in tight oil reservoirs and in the determination and design of the optimal injection-production scheme to maximize the oil recovery factor for multi-fractured horizontal wells

Simulation Study of CO2-EOR in Tight Oil Reservoirs with Complex Fracture Geometries

The recent development of tight oil reservoirs has led to an increase in oil production in the past several years due to the progress in horizontal drilling and hydraulic fracturing. However, the expected oil recovery factor from these reservoirs is still very low. CO(2)-based enhanced oil recovery is a suitable solution to improve the recovery. One challenge of the estimation of the recovery is to properly model complex hydraulic fracture geometries which are often assumed to be planar due to the limitation of local grid refinement approach. More flexible methods like the use of unstructured grids can significantly increase the computational demand. In this study, we introduce an efficient methodology of the embedded discrete fracture model to explicitly model complex fracture geometries. We build a compositional reservoir model to investigate the effects of complex fracture geometries on performance of CO(2) Huff-n-Puff and CO(2) continuous injection. The results confirm that the appropriate modelling of the fracture geometry plays a critical role in the estimation of the incremental oil recovery. This study also provides new insights into the understanding of the impacts of CO(2) molecular diffusion, reservoir permeability, and natural fractures on the performance of CO(2)-EOR processes in tight oil reservoirs

Performance evaluation of CO2 EOR in tight oil formation with complex fracture geometries

The recent development of tight oil reservoirs has led to an increase in oil production in the past several years due to the progress in horizontal drilling and hydraulic fracturing. However, the oil recovery factor expected is still very low even after the wells have been fractured and therefore, tight formations are considered good candidates for enhanced oil recovery (EOR). One of the most suitable solutions to improve the oil recovery is the carbon dioxide (CO2)-based EOR. Although the injection of CO2 is not new for conventional oil reservoirs, its practice in tight oil formations is still a relatively novel idea. Two injection-production strategies are often employed: continuous CO2 injection or flooding and CO2 Huff-n-Puff. However, it is not clear which scenario is the best strategy to achieve an optimal recovery, which highly depends on many uncertain reservoir and fracture parameters and it is not clearly understood until recently. Another challenge of the estimation of the incremental recovery of these injection approaches is to properly model the hydraulic fractures and CO2 transport mechanism. The actual hydraulic fracturing process often creates complex fracture networks, especially when the fracture propagates in a formation with a large amount of pre-existing natural fractures. In this study, the CO2-EOR effectiveness is simulated and analyzed by comparing the Huff-n-Puff and the continuous injection scenarios. The effect of matrix permeability on the comparison of well performance of these two scenarios was investigated. Subsequently, Design of Experiment and Response Surface Methodology is used to perform sensitivity studies with four uncertain parameters including matrix permeability, number of wells, well pattern, and fracture half-length to determine the best injection approach. In addition, an efficient methodology of embedded discrete fracture model (EDFM) is introduced to explicitly model complex fracture geometries. The effects of complex fracture geometries on well performance of CO2 Huff-n-Puff and CO2 continuous injection were also investigated as well as the effect of natural fractures. The analysis of the CO2-EOR effectiveness confirms that the appropriate modelling of the complex fractures geometry plays a critical role in estimation of the incremental oil recovery. This study provides new insights into a better understanding of the impacts of reservoir permeability, complex hydraulic fractures and natural fractures on well performance during CO2-EOR process in tight oil reservoirs and in the determination and design of the optimal injection-production scheme to maximize the oil recovery factor for multi-fractured horizontal wells.Petroleum and Geosystems Engineerin

Evaluación técnica económica para incrementar la producción de mineral de la concesión minera Víctor-Jesús - provincia de Pataz - La Libertad

En el marco de la evaluación técnica económica de proyectos, el presente estudio tiene como propósito analizar el incremento de la producción de mineral de la concesión minera Víctor Jesús, provincia de Pataz – La Libertad. En particular su objetivo es evaluar técnica y económicamente el incremento de la producción de las reservas remanentes de la veta Rosario y de las reservas aún no explotadas de la veta Carmen en la concesión minera. Se registró y analizó la historia de producción planificada originalmente que sirvió para actualizar las reservas remanentes. Con esta información se propone un nuevo plan de mejora y una expansión para incrementar la producción con el método de Corte y Relleno ascendente tecnificado, el cual genera un incremento de producción de mineral de 1.2 toneladas diarias a 26.32 toneladas al día. La evaluación económica del incremento de producción y de la expansión resultan positivas. En conclusión, se muestra que existen reservas remantes y recursos contingentes suficientes para implementar el incremento de producción y la expansión de la concesión minera Víctor Jesús y se demuestra que el estudio de investigación es viable técnica y económicamente

A Comprehensive Numerical Model for Simulating Fluid Transport in Nanopores

Since a large amount of nanopores exist in tight oil reservoirs, fluid transport in nanopores is complex due to large capillary pressure. Recent studies only focus on the effect of nanopore confinement on single-well performance with simple planar fractures in tight oil reservoirs. Its impacts on multi-well performance with complex fracture geometries have not been reported. In this study, a numerical model was developed to investigate the effect of confined phase behavior on cumulative oil and gas production of four horizontal wells with different fracture geometries. Its pore sizes were divided into five regions based on nanopore size distribution. Then, fluid properties were evaluated under different levels of capillary pressure using Peng-Robinson equation of state. Afterwards, an efficient approach of Embedded Discrete Fracture Model (EDFM) was applied to explicitly model hydraulic and natural fractures in the reservoirs. Finally, three fracture geometries, i.e. non-planar hydraulic fractures, nonplanar hydraulic fractures with one set natural fractures, and non-planar hydraulic fractures with two sets natural fractures, are evaluated. The multi-well performance with confined phase behavior is analyzed with permeabilities of 0.01 md and 0.1 md. This work improves the analysis of capillarity effect on multi-well performance with complex fracture geometries in tight oil reservoirs.National Natural Science Foundation of China [51674010]; National Science and Technology Major Project of China [2016ZX05014]; China Scholarship Council (CSC) [201506010205]SCI(E)ARTICLE