MULTI-SOLID MODEL MODIFIED TO PREDICT PARAFFIN PRECIPITATION Ciencia, Tecnología y Futuro MULTI-SOLID MODEL MODIFIED TO PREDICT PARAFFIN PRECIPITATION IN PETROLEUM FLUIDS AT HIGH TEMPERATURES AND PRESSURES Juan-Carlos-M. Escobar-Remolina1*, Wilson Barrios-Ortiz2 and Gildardo Santoyo-Ramírez3 1, 2 Ecopetrol S.A. - Superintendencia de Yacimientos, Bogotá, Colombia 3 Gems Ltda, Bucaramanga, Santander, Colombia e-mail: [email protected] (Received April 2, 2008; Accepted November 25, 2009) thermodynamic structure has been modified in order to calculate cloud point, fluidity and amount of pre- Acipitated wax under a wide range of temperature conditions, composition, and high pressures. The model is based on a combination of ideal solution concepts, fluid characterization, and formation of multiple solid phases using Cubic State Equations. The experimental data utilized for testing the prediction capacity and potentiality of a model exhibit different characteristics: continuous series synthetic systems of heavy alkanes, discontinuous series, and dead or living petroleum fluids with indefinite fractions such as C7+, C10+, C20+, and C30+. The samples were taken from the literature, petroleum fluids from the main Colombian reservoirs, and some samples of Bolivian fluids. Results presented in this paper show the minimum standard deviations between experimental data and data calculated with a model. This allows a progress in decision-making processes for flow assurance in reservoirs, wells, and surface facilities in the petroleum industry. Keywords: multi-solid model, paraffin precipitation, high pressure and temperature, flow assurance. * To whom correspondence may be addressed CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 5 Dic. 2009 35 JUAN-CARLOS-M ESCOBAR-REMOLINA et al. n el presente trabajo se ha modificado una estructura termodinámica para el cálculo del punto de Enube, de fluidez y cantidad de cera precipitada en un amplio rango de condiciones de temperatura, composición y altas presiones. El modelo se fundamenta en una combinación de los conceptos de solución ideal, caracterización del fluido y de formación de fases sólidas múltiples empleando ecuaciones de estado cúbicas (EDEC). Los datos experimentales usados para probar la capacidad de predicción del modelo y su potencialidad tienen características variadas: sistemas sintéticos de series continúas de alcanos pesados, series discontinuas y fluidos del petróleo vivo y muerto con fracciones indefinidas como C7+, C10+, C20+, y C30+. Las muestras se tomaron de la literatura, fluidos de petróleos de los principales yacimientos Colombianos y algunas muestras de fluidos Bolivianos. Los resultados que se presentan en este trabajo muestran desviaciones mínimas entre los datos experimentales y los calculados con el modelo. Lo anterior permite por tanto, un avance en la toma de decisiones para aseguramiento del flujo en yacimiento, pozos y facilidades de superficie en la industria petrolera. Palabras Clave: modelo multi-sólido, precipitación de parafinas, elevadas presiones y temperaturas, aseguramiento del flujo. 36 CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 5 Dic. 2009 MULTI-SOLID MODEL MODIFIED TO PREDICT PARAFFIN PRECIPITATION INTRODUCTION EHNQRZQLV:33:33DQGWKHDPRXQWRISUHFLSLWDWHG ZD[HYDOXDWLRQVDUHEDVHGRQWKHPHDVXUHPHQWRIGHDG Fluids produced from petroleum reservoirs contain RLO JDVIUHHRLO 7KLVFDQOHDGWRFRQVHUYDWLYHHVWLPD- SDUDI¿QFRPSRXQGVRIKLJKPROHFXODUZHLJKW$WORZ WLRQVDQGSRWHQWLDOO\H[SHQVLYHVROXWLRQVLQÀRZOLQHV WHPSHUDWXUHV DQGHYHQDWKLJKWHPSHUDWXUHV KHDYLHU WUDQVSRUWLQJQRQVWDELOL]HGSHWUROHXPSDUWLFXODUO\ SDUDI¿QPROHFXOHVFU\VWDOOL]HDQGEORFNSURGXFWLRQ UHJDUGLQJLQVXODWLRQDQGGHFLVLRQPDNLQJSURFHVVHV SLSHVDQGVXUIDFHOLQHV)XUWKHUPRUHVRPHSDUDI¿Q UHODWHGWRÀRZDVVXUDQFH7KHUHIRUHKLJKO\UHOLDEOH PROHFXOHV³SUHFLSLWDWH´LQWKHLQWHUQDOÀXLGPDVVDQG PHDVXUHPHQWVRI:33WKHDPRXQWRISUHFLSLWDWHGSDUD are transported in a suspended manner. 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