Experimental Investigation and Modeling of Asphaltene Precipitation Due to Gas Injection

Asphaltene instability is one of the major problems in gas injection projects throughout the world. Numerous models have been developed to predict asphaltene precipitation; The scaling equation is an attractive tool because of its simplicity and not involving complex properties of asphaltene. In this work, a new scaling model is presented to account for asphaltene precipitation due to gas injection at reservoir conditions. Extensive published data from literature have been used in model preparation. To check predictive capability of the equation, miscible gas injection experiments are conducted for a southwest Iranian oil reservoir. Experimental results show that methane injection has significant effect on asphaltene precipitation and direct effect of temperature is less severe than other parameters. In addition to the accuracy and simplicity, the proposed equation provides universal parameters which make this approach novel for evaluation of future gas injection projects when simple PVT data are available.