Dolphin Energy KHI Removal

The Client's Needs

The objective of Dolphin Energy’s Industrial Wastewater Management Project is threefold: to reduce the volume of wastewater currently being injected into the existing re-injection wells at the Ras Laffan gas plant, to eliminate Kinetic Hydrate Inhibitor polymers from the residual wastewater now re-injected, and to reduce the volume of desalinated water purchased from external sources.

A solution had to be found in particular for the KHI polymer removal due to new Qatari regulations. Industry regulators in Qatar had concluded that the presence of KHI polymers in the re-jected water leads to long-term reservoir damage and possible groundwater pollution. However, KHI is a low-dosage inhibitor that has become an alternative to traditional thermodynamic inhibitors like methanol and MEG. Reverting to these tradition inhibitors would increase capital and operating costs. 

The Solution

Dolphin Energy awarded Veolia Water Technologies a research and development study to evaluate a wide range of water treatment technologies for treating produced water that contains KHI. 

Through its research and development study, Veolia identified evaporation as a feasible process to treat KHI-laden wastewaters and generate a recovered water stream free of KHI. Soon after the study results were reported, Dolphin Energy initiated a tender process for supply of the industrial system to treat their KHI wastewaters at Ras Laffan Industrial City. After years of collaborative interactions, Veolia won the competitive bid to supply the industrial solution.

Process Description

Veolia’s system is divided into two steps of evaporation: the first step is driven through Mechanical Vapor Recompression (MVR) and the second step is driven through Low-Pressure (LP) steam. For both steps, forced circulation technology was selected due to the viscous nature of the concentrated organic wastewater. In order to further enhance the process distillate quality, vapor washers are also included at the MVR. 

The plant will have a capacity of 40 m3 /hr and will start operations in 2017. Dolphin Energy´s onshore gas facility will rely on the high performance of Veolia´s system to maintain gas extraction operations during KHI injection (seasonally November through May of each year).

Results

Dolphin Energy will be one of the first leading companies to use pioneering evaporation technology for this specific purpose. It will enhance the client’s reputation, strengthen its environmental credentials and deepen its commitment to supporting Qatar’s sustainability agenda.

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