Optimization of Flare Gas Recovery in Oil and Gas Processing Plants, from Challenges to Opportunities

Abstract A flare network is an important part of the pressure-relieving system of hydrocarbon processing plants. The primary function of a flare system is to protect the plant and personnel by reliably and safely disposing of flammable waste gas by burning it into the atmosphere during an emergency. However, the excess gas generated in oil and gas operations may also be continuously sent to the flare network to be burned. This routine flaring releases emissions that include greenhouse gases, nitrogen oxides, sulfur dioxide and any unburned hydrocarbons, all of which contribute to the total emissions from the plant. In this paper we describe a feasibility study of low to zero routine flaring in a processing plant. The process under study involved recovering flare gas and routing it back to the plant for appropriate use. Detailed design, economic assessment, and evaluation of a flare reduction strategy is presented through modeling of the complete system from production to facilities to the flare system and gas recovery method of choice. Reciprocating compressor design and optimization to maximize throughput and minimize emissions is featured. The possibility of occurrence of different operating hazards is studied, including brittle fracture, hydrate, and dry ice formation in the flare network. This study is helpful to detect and mitigate the risk of pipe rupture caused by flare line embrittlement.