Simulation of the Dispersion of Carbon Dioxide During Accidental Releases from Gas Processing Facilities

Abstract

Carbon capture and storage (CCS) from oil facilities is an important and effective way to reduce the concentration of carbon dioxide in the atmosphere. Consequently, gas-processing facilities will be dealing with a tremendous quantity of CO2 with high pressure. Therefore, the aim of this study is to simulate the dispersal of CO2 gas leakage from high-pressure pipelines of the gas-processing facilities. The modeling of CO2 leakage from pipelines at CCS process has been problematic because of the lack of appropriate source term models that handle the complex behavior of CO2 correctly during release. In this study, OLGA 7 simulator was utilized for predicting outflow rates and duration of ruptured CO2 pipelines at different leakage scenarios (leakage sizes). OLGA 7 simulator was selected due to its capabilities in simulating gas pipeline leak scenarios in various designs and operating conditions such as Operation Pressure, Isolation valve spacing (IVS), and Emergency response time (ERT). The results of the OLGA 7 simulator provide appropriate source conditions for the selected dispersion models. Gaussian atmospheric dispersion model was chosen to simulate the CO2 gas dispersion behavior within the platform; it is very effective and simple. The effect of operating and design parameters (Operation Pressure, Isolation valve spacing (IVS), and Emergency response time (ERT) on the dispersion behaviors of the released gas in different leak scenarios was studied. The results showed that the emergency response time has the greatest effect on the mass of the accumulated leak (kg) and thus on the level of gas concentrations, and this effect is more pronounced for large leakage sizes. Also, the results showed that the emergency response time had no effect on levels of distance gas concentrations, but it had a significant effect on the duration of the leaking.