Models for Estimating the Shrinkage Factor in the Mixtures of Diluents with Colombian Heavy Crude Oils

Abstract

Abstract The production of heavy and extra heavy crude by dilution with lighter hydrocarbons produce volumetric differences, which are associated to diluent losses attributed to volatilization phenomena. This article present results of the production data analysis from different fields of heavy and extra Oil in Colombia, where the assessment of models for determine the shrinkage factor in mixing process of heavy crude oil with diluents were incorporated. To develop this work, a model to predict the volume shrinkage occurring in heavy light oil mixtures was defined. The analysis was conducted with 25 types of crude oil and 11 diluents, their mixing properties of viscosity and API gravity were measured and calculated. Several authors have proposed models to determine shrinkage factor (Erno, Booker and API). Those models were evaluated with production data, then using multivariable regression techniques an adjusted model was proposed, Results shown the fraction of diluent and the value of the difference between the inverse of the densities of oil and diluent are the important variables in this new model. \Finally the model was incorporated in the volumetric production balance of these fields.