مدل سازي عددي فرآيند رانش گاز محلول در مخازن نفت سنگين

چكيده انگليسي :

Numerical Modeling of Solution Gas Drive in Heavy Oil Reservoirs Mojtaba Golbin m golbin@ce iut ac ir Date of Submission September 22 2013 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors M R Ehsani ehsani@cc iut ac ir Abstract Increasing global demand for oil and reduce production of light oil has led to more attention to heavy oils resource Solution gas drive is one of the most effective methods is considered in terms of cost in heavy oil production The objective of this research was to develop a numerical model for bubble growth and then a dynamic model for simulation of Solution gas drive mechanism The bubble growth is one of the most important steps in solution gas drive process In bubble growth model both hydrodynamic and diffusion forces are considered The Navier Stokes equation and the mass conservation equation have been used for considering the hydrodynamic and diffusion forces in this modeling respectively The assumptions used in the proposed model can be mentioned as gas liquid equilibrium at the interface instantaneous nucleation Henry equilibrium relationship constant density of the liquid spherical gas bubble and constant time depended pressure drop condition Newton s method was used for linearization of equations The major difference of this model with other models is that in the present model real gas behavior is considered for gas treatment In order to study the validation of the model the model results are compared to the Pooladi compatibility with the experimental data In the next step the effect of various parameters such as viscosity diffusion coefficient surface tension initial bubble radius depletion rate are studied on the bubble growth The results show that in early times the effect of hydrodynamic forces are more important than that of diffusion forces so that it prevents the bubble growth but finally the growth is controlled by diffusion forces Also the results show that nucleation can occur before reaching to the minimum point on the P V curve And even after nucleation reservoir pressure reduction will continue In order to dynamic modeling of solution gas drive process a dynamic model is proposed There are three adjustable parameters in proposed model which is adjusted according to results of depletion tests All of adjustable parameters have a physical meaning and are only function of the rock fluid system and are independed of the experimental condition specially the depletion rate In the proposed model A first order equation which is depended on gas saturation is used which is adjusted according to results of depletion rates To account for the effect of viscous forces on gas mobility relative permeability functions were introduced that not only depend on gas saturation but also on local oil phase velocity and viscosity Results showed that the average relative errors between experimental results and proposed model according to power law and exponential distribution of microbubbles are 4 5 and 6 respectively Also Results was showed that this model has a good constancy with experimental results Keywords Solution gas drive heavy oil primary production dynamic modeling bubble growth PDF created with pdfFactory trial version www pdffactory com

گلبين، مجتبي

مدل سازي عددي فرآيند رانش گاز محلول در مخازن نفت سنگين

برداشت اوليه , مدل سازي ديناميكي , رشد حباب