FEED for Debottlenecking of NGL-3 Extraction Unit
Reference: LT14109400 10/30/2014, Location: Middle East
Category: Engineering
Scope of Work
The project included upgrade of the NGL-3 Extraction Unit to process total feed gas of 983 MMSCFD (760 of NFA, 200 Al-Shaheen and 23 Sour gas) with guaranteed Ethane recovery of 83%.
Prior to the implementation of the RAG & Flare Mitigation Project, Snamprogetti were contracted to upgrade the NGL-3 Extraction Unit to process 1023 MMSCFD feed gas with guaranteed C2 recovery of 85%.
This could not be achieved. Another consultant, PFI, carried out an adequacy study on the Snamprogetti design and identified various factors that resulted in lower C2 recovery. Some of these factors related to design deficiencies and could be the cause of existing Plant Operations problems and inefficiencies. Further study of these operational problems is required.
Problems include:
Liquid carry-over (snowball effect) - heavy liquid production at the pre-flash column top section.
Methane slippage along with C2 - snowball effect results in methane content in the Ethane Rich Gas which goes as feed to the ethylene plant to be higher than maximum.
Less propane generation from E-45 propane generator leads to NGL-4 refrigeration compressor problems.
As the extraction unit is forced to operate outside of process parameters (temperature, pressure, flow, and level), the reliability and integrity of the equipment is compromised.
Study is in progress and due to complete in July 2013. Study package will detail the Scope for FEED.
Location: Contracts Dept. - Engineering Division, Qatar Petroleum, Fareej Bin Dirham,Al-Handasa Complex, Mezzanine Fl, Room A-M03,B-Ring Rd, Doha
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