Increase flared gas recovery and emission reduction by separator optimization

Abstract

To combat the increased emission rate and energy waste, a business case for an online optimizer was established to examine the energy-saving and emission reduction figures. Prior to embarking on this study, there is a need to understand the performance of oil and gas companies in managing the continuous flared gas. From the data gathered, it was quite evident that oil and gas operators do not significantly invest in optimizing gas flaring. The survey has included 706 participants from more than 59 different countries and indicated that there is a lack of awareness where regular monitoring of flared gas is overlooked. The survey shows about 17.6% of the participants never analyzed flared gas compositions, while only 36.6% of participants do this on monthly basis. More importantly, the survey indicated that most participants don’t update their process operating conditions in response to day and night or yearly seasons thermal conditions. The optimization study is primarily focusing on having an online flared gas controller technique to continually monitor and analyze flared gas compositions with an intention to automatically manipulate separator operating conditions to increase the flared gas recovery. This approach was tested using a dynamic model developed for three real offshore and onshore oil and gas fields in Egypt and Saudi Arabia. In the three cases of study, this approach was able to adjust the operating conditions of the separator based on the flared gas analysis and the objective function identified to largely recover heavy hydrocarbons and control flared gas.