At the end of 2012, Wepuko Pahnke was contracted by the Brazilian oil production company Petrobras for the delivery and installation of six three-plunger pumps. These pumps are intended for what is known as “well service” on offshore crude oil production ships – the FPSOs = floating production storage and offloading units. The pumps including the drive unit, lubricant supply and pulsation damping are mounted on a skid weighing a total of 48 tons.
- Installed power 1,230 KW
- Maximum operating pressure 278 bar
- Flow rate 120 m³/ h
Well service pumps are used for hydrostatic pressure tests in the risers (metallic-flexible pipelines) between the FPSOs and the well heads. Additionally these service units will support the operation of pipeline pigs, in depths up to 2,000 m below sea level.
Claus Kalmbach, Project Manager at Wepuko Pahnke, sealed the deal for the company. Now, that the first skid is fully assembled he reviews and states: “The requirements and specifications we have to meet, are truly challenging. Nevertheless, we successfully developed, fabricated and assembled a new solution in about 18 months starting from order placement to the final assembly of the skid. Now the whole unit goes onto the test bed.
Michael Pahnke, owner and managing director, saw the greatest challenge in “fitting such a high pumping output onto the smallest possible footprint. This high specific output, the minimized pulsation and the quick order processing surely constitute the key to success. This result of performance is opening entirely new markets for Wepuko Pahnke” and, according to him, there are already other applications in which this new development is being offered and demanded.
For the realisation of this project, Wepuko Pahnke utilized their existing high-pressure plunger pump technology. However, the desired performance characteristics could not be achieved with a mere scale-up on the basis of existing models. Instead, the developers under Martin Graser and Daniel Tomaselli had to rise to the challenge of developing a compact displacement pump. “Our objective was to optimize the DP 532-250 high-pressure plunger pump in terms of the space requirements and in terms of the suction behaviour – in other words, to achieve the lowest possible NPSH,” Graser says. “We put a lot of development and simulation effort into the valves and achieved the expected results.
The installation location on the FPSOs is classified as explosion zone 2. Therefore the electrical installation is designed according to the regulations for explosion-prone areas in zone 2, explosion group IIA and temperature class T3 for ambient temperatures from 10 to 45°C.
The fully assembled pump skid will now be subjected to extensive tests on the Wepuko test bed in the presence of operator representatives and, after acceptance, shipped to Brazil for installation on the FPSO. In the meantime the production of the next 5 skids is in full swing at Wepuko Pahnke.