123engr
Chemical
- Dec 10, 2012
- 35
- 0
- 0
I am involve in a project where we want to transport the produced water discharge from flotation cells through a pipeline to an injection platform. There are two flotation cells at the production platform and each working at atmospheric pressure and have a design pressure of 5 oz./in2.
Currently, the flotation cells are discharging the produced water overboard, but to meet the environmental regulation due to the location of the platform, we are to design a pipeline system which requires a pipeline pump to transport the liquid. The produced water discharge from the flotation cells are controlled by the LCV on the water outlet which are controlled by the level transmitter on the vessels.
From our study, connecting the flotation cell water outlet line directly to the pipeline pumps suction is a major problem because of the working level available in the flotation cells. A surge vessel/tank was proposed, but the total weight of vessel/tank and fluid is a major concern on the proposed location for the equipment which is expected to be located on a platform extension. The structural integrity of the platform extension cannot be guaranteed, and the client do not want construct additional beams to carry the load. Therefore, we considered another option.
If we use a fixed speed pumps, we need to provide a minimum flow recirculation line. Convectional method is to recirculate back into the pumping source, but the discharge pressure of the pump is 200 psig, while the design pressure of the source vessel is 5 oz/in2. This means that we need to choke the minimum flow and drop the pressure as low as the vessel can take. This is not an ideal option in order not to distabilise the flotation cells operation.
Based on this, I was tasked to study the effect of recirculating into the upstream equipment of the flotation cells. The upstream equipment are FWKO (MAWP - 125 psig & Operating Pressure- 40 psig) and Water Skimmer (MAWP - 75 psig & Operating Pressure- 10 psig).
My concerns is that if we recirculate back into the upstream equipment, their operation and separation dynamics will be disrupt. Therefore, the separation will be greatly affected.
Please, I would like to know the areas I need to focus on in my study and what are the pros and cons if the water is recirculated to the upstream equipment as considered by the client.
Your insight is highly appreciated.
I am what I am by His grace
Currently, the flotation cells are discharging the produced water overboard, but to meet the environmental regulation due to the location of the platform, we are to design a pipeline system which requires a pipeline pump to transport the liquid. The produced water discharge from the flotation cells are controlled by the LCV on the water outlet which are controlled by the level transmitter on the vessels.
From our study, connecting the flotation cell water outlet line directly to the pipeline pumps suction is a major problem because of the working level available in the flotation cells. A surge vessel/tank was proposed, but the total weight of vessel/tank and fluid is a major concern on the proposed location for the equipment which is expected to be located on a platform extension. The structural integrity of the platform extension cannot be guaranteed, and the client do not want construct additional beams to carry the load. Therefore, we considered another option.
If we use a fixed speed pumps, we need to provide a minimum flow recirculation line. Convectional method is to recirculate back into the pumping source, but the discharge pressure of the pump is 200 psig, while the design pressure of the source vessel is 5 oz/in2. This means that we need to choke the minimum flow and drop the pressure as low as the vessel can take. This is not an ideal option in order not to distabilise the flotation cells operation.
Based on this, I was tasked to study the effect of recirculating into the upstream equipment of the flotation cells. The upstream equipment are FWKO (MAWP - 125 psig & Operating Pressure- 40 psig) and Water Skimmer (MAWP - 75 psig & Operating Pressure- 10 psig).
My concerns is that if we recirculate back into the upstream equipment, their operation and separation dynamics will be disrupt. Therefore, the separation will be greatly affected.
Please, I would like to know the areas I need to focus on in my study and what are the pros and cons if the water is recirculated to the upstream equipment as considered by the client.
Your insight is highly appreciated.
I am what I am by His grace
