EOR Returned Polymer Removal from Produced Water by Chemical Coagulation – A Successful Pilot Testing

2021 ◽  
Author(s):  
Robert Zagitov ◽  
Jaisankar Subramanian ◽  
Srinivasa Rao Gopisetty ◽  
Avinash Kumar ◽  
Vinay Mathur ◽  
...  

Abstract Severe fouling of crude oil and produced water treatment equipment of Mangala Processing Terminal (MPT) with elastic deposits has been observed after EOR polymer breaking through to the producing wells. Fouling by polymer containing solids caused the system bottlenecking impacting on crude production rates and deterioration of water quality for injection due to increase of total solids loading. The objective of the study included developing the water treatment technology for removing the returned polymer, developing the pilot run for implementation of the technology and scaling up the process if the pilot shows success. Crude processed at MPT is produced from Mangala, Bhagyam and Aishwarya fields which are located at the north-west part of India. Full field polymer flooding has been implemented in the Mangala field from 2015. Fouling of downhole and topside equipment with elastic deposits has been reported soon after polymer breakthrough the same year. For reducing the fouling potential and solids loading, the concept of removing the returned polymer from produced water has been considered as beneficial. Removal of polymer through the chemical coagulation was considered for developing. Extensive laboratory and bench testing have been carried out. Based on the laboratory results, the pilot was developed and carried out on the flotation equipment available at MPT. In the laboratory and bench test for polymer coagulation, over 70% polymer removal was achieved with non-sticky flocks and minimal sludge. The tests also demonstrated reduced suspended solids, residual oil and filterability improvement of treated water. The pilot run confirmed effectiveness of the chemical coagulation process to remove polymer. Polymer removal > 70% was observed during the pilot. Oil removal from produced water at 60-80% was seen. Cloud point of polymer remaining in water increased from 60°C to > 110°C indicating on the significant potential reduction of remaining polymer to precipitate from treated water. The pilot results demonstrated on the applicability of the technology of chemical polymer removal at MPT and will be used for scaling up the treatment facilities.

2021 ◽  
Author(s):  
Steinar Asdahl ◽  
Johann Jansen van Rensburg ◽  
Martin Einarson Waag ◽  
Rune Glenna Nilssen

Abstract Traditionally, produced water from production separators is handled by multiple steps and different technologies in order to meet the required quality for either discharge or reinjection of the water. The development of the latest Compact Flotation Unit (CFU) technology has unlocked the potential for savings on cost, complexity, footprint and weight for the produced water treatment system. The developed CFU technology has proven applicable through field testing as a single treatment technology for reducing Oil-in-Water (OiW) content directly from tie-in at separator and still meet stringent requirements for outlet OiW quality. Field tests were conducted with inlet OiW concentration ranging from 200-2000 ppm, achieving results in the range 2.5 to 21 ppm only with a two-stage latest generation CFU. Compared to a traditional produced water system setup consisting of de-oiling hydrocyclones and a horizontal degassing vessel, the savings in footprint and operational weight is estimated to 54 % and 53 % respectively utilizing a two-stage CFU for a system with a design capacity of 76.000 BWPD. Furthermore, the development of the latest generation CFU technology has enabled the retrofit concept, incorporating the developed CFU internals into existing gravity separation based produced water vessels, converting them to more efficient flotation vessels with increased capacity. For brownfield and debottlenecking applications, operators are challenged by increasing water cut from maturing wells, and as a result exceeding the facilities design capacity for produced water treatment. This challenge is often further reinforced by increasingly stricter environmental legislation for OiW content for discharge or re-injection. The retrofit concept will offer a highly cost-, footprint- and weight-efficient solutions to these challenges utilizing existing vessels. Benefits of the retrofit concept: Bring proven and unique performance of the technology to other produced water separation vessels helping the operators improve the separation efficiency and increase throughput while meeting discharge requirementsShort execution time compared to installation of new process equipmentLow cost compared to installation of new process equipmentUtilization of existing equipment saves valuable footprint.


2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Imam Setiadi ◽  
I Putu Angga Kristyawan

Low levels of clean water supply in the Tanjung Tengah village causing the high price of water. value of Fe and TDS in the village raw water is high. The value of Fe content is 388 mg/L and TDS value is 12930 mg / L. The installation of salty peat water treatment technology were done to overcome this problem. The Salty peat water treatment technology consists of coagulation flocculation system, clarifier, filtration, reverse osmosis and a distribution systems. Results showed that this treatment efficiency reaches 99%. Where the iron content of the treated water is less than 0.003 mg / L, with a TDS value down to be 77 mg / L. The treated water also meet drinking water quality standards. Keywords : Clean Water, Salty Peat Water, Reverse Osmosis, Iron and TDS.


2020 ◽  
Vol 92 (10) ◽  
pp. 1695-1700
Author(s):  
Xinchao Wei ◽  
Mohammad Kazemi ◽  
Shicheng Zhang ◽  
Frederick A. Wolfe

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