Iranian Journal of Chemical Engineering (IJChE)

Abstract The gelling of waxy crudes and the deposition of wax on the inner walls of pipelines present a costly problem in the production and transportation of oil. The object of the present study is to investigate the factors that affect the deposition of the paraffin wax on the pipe surface under different conditions using a flow loop system. A series of experiments on wax deposition from a mixture of waxy oil have been performed in a 65cm by 1cm ID flow loop in both laminar and turbulent flow regime. These experiments were done to study the effect of some important factors on the amount of deposited wax on the pipe wall. These factors consist of flow rate, residence time, wax concentration and temperature difference between mixture and pipe wall. It was found that the wax deposition increases with increasing temperature difference and residence time, but the effect of flow rate depends on flow regime. The other goal is mathematical modeling of wax deposition for a multi-component hydrocarbon mixture. The procedure for generating the model is described in detail. Finally, the results obtained from the model were compared with experimental data. It was found that there is an acceptable match between experimental and theoretical data and to some extent, this confirms the validity of the model and also the ability of the developed model to predict the wax deposition on pipelines under different operational condition.

Abstract In this paper, a simplified formulation for a compositional reservoir simulator is presented. These type of simulators are used when interphase mass transfer depends on phase composition as well as pressure. The procedure for solving compositional model equations is completely described. The Peng Robinson equation of state is used for preparing a compositional thermodynamic program for equilibrium calculation, property estimation and pseudo component determination. Another purpose of this paper is to prepare an experimental apparatus for the displacement of oil by gas injection. In each test, oil recovery as a function of injected pore volume was measured. The application of the developed simulator to simulate the results of the oil recovery from slim tube experiments is also presented. Finally, the model was run for a 2-D reservoir. Acceptable trends were obtained from the model predictions.