ASFALTENOS, UN DAÑO SEVERO EN YACIMIENTOS ALTAMENTE SUBSATURADOS DE ACEITE VOLÁTIL

Aphaltene organic precipitation and deposition is known as a severe problem at reservoir level, especially in high sub-saturated reservoirs, due to the asphaltic deposition is extended beyond wellbore. Literature cases show a high concentration of asphaltene precipitation and deposition in near conditions to bubble point, a critical condition in high sub-saturated reservoirs. These reservoirs have a mayor probability to generate asphaltic deposition, especially in volatile systems although these have low weight asphaltene concentration. This article presents asphaltene precipitation-deposition study and modelling for high sub ¿saturated volatile reservoir in STARS´ CMG reservoir simulator. This study developing in a Colombian field involved three aspects: 1) oil effective permeability reductions (laboratory test), 2) productivity impact (production history) and 3) damage at reservoir level (deposition modelling). Precipitation ¿deposition modeling is built from fluid-precipitation models in Winprop and deposition modelling in STARS. The deposition envelope was generated from fugacity law and adjusted through solid molar volume and binary interaction level with high components. The asphaltene volume flocculate is controlled by reaction rate in a simple chemical model, and, the amount of asphaltene deposited is modelled by mass transfer equation.