Val D’Agri oil and associated gas increases, how gas processing challenges were solved

​In 2008, ENI (operating partner) and Shell Italia EP (non-operating partner) planned to increase oil production in Val D’Agri, ultimately increasing associated gas. To process the increased associated gas without altering the Sulphur recovery trains, an acid gas removal unit (AGRU), an acid gas enrichment unit (AGEU), and a thermal oxidizer was designed. In 2009, it was discovered that the additional associated gas contained more mercaptans than expected, which warranted the project scope to be re-assessed. During this evaluation, it was determined that the proposed design could not satisfy the requirements of processing the desired gas throughput without sacrificing sales gas specifications or stack SO2 emission specifications. Different design options were evaluated to meet the specifications while minimizing the modifications to existing equipment and the original design. The chosen solution maintained the design but was enhanced by swapping the solvents in the AGRUs and the installation of a CANSOLV unit downstream of the thermal oxidizer to remove SO2 produced by the combustion of additional mercaptans. This paper details the challenges in debottlenecking Val D’Agri to process the increased associated gas, the advantages and disadvantages of solution options, and some of the lessons learned from a CANSOLV unit in operation.