Petrobas Chooses In-Rack Flow Computer Flyer0 pages
Where | ||
Automation | ||
^^^^« ^ Connects. | m |
Petrobras Chooses In-Rack
nnnnFlow Computers f^*ni0Nna,ural
nnnnIn the heart of this Brazilian rainforest, in the
nnnnUrucu province, 38 flow streams of natural gas
nnnnare transferred to an oil treatment plant owned by
nnnnPetrobras. The Urucu province is the second largest
nnnnnatural gas reserve in Brazil with an average daily
nnnnproduction of over five million cubic meters per
nnnnday. Because of recent regulations published by the
nnnnNational Oil Agency requiring a better measurement
nnnnof accuracy for oil volume transfer, Petrobras needed
nnnnto review their existing installations and specify
nnnnequipment compliant with these new regulations.
nnnn"If we had chosen the classic model of dedicated flow
nnnncomputers (EMED), the costs and the engineering
nnnnfor the presentation of results would be very high,
nnnnsince for the implementation of 68 EMEDs we had an
nnnnaverage cost of U$ 40.000 per unit, where the units
nnnnwould vary from 4" to 10" and pressure class varying
nnnnbetween 300# and 2500# (19 units)," said Francisco
nnnnCarlos Campana Aragon, Senior Equipment Engineer
nnnnfor Petrobras.
nnnnProSoft
nnnnTECHNOLOGY
nnnnBecause of this high cost, this was clearly not an
nnnnoption for Petrobras. Aragon then discovered ProSoft
nnnnTechnology's in-rack flow computers for Allen-Bradley
nnnnPLC and SLC platforms.
nnnnFour 2100-AGA modules were installed in an 8-slot
nnnnAllen-Bradley chassis (PLC 5/80) to calculate the
nnnnvolume for the 38 flow streams transferred through
nnnnthe oil treatment plant. These modules continuously
nnnntransfer calculation results to the PLC, providing total
nnnncompliance with the API 21.1 standard.
nnnnThe gas then leaves the oil treatment plant and is
nnnntransferred 12 km to the oil extraction plant where
nnnn16 flow computers (MVI46-AFC) calculate the flow
nnnnrates and gas volumes. The MVI46-AFC modules
nnnncommunicate through the backplane with an SLC 5/03
nnnnfor each extraction plant.
nnnn"Thanks to the interaction between ProSoft's MVI46-
nnnnAFC in-chassis flow computer module and the SLC
nnnnprocessor, we could implement an automated system
nnnnfor calculation and presentation of results totally
nnnncompatible with the level of autojja^^l^Uj^^^w^
nnnnplant," said Aragon. "the cost would have been much
nnnnhigher using the classi^ri^BjWted flow comp]tatefs--J
nnnn(EMEDs) than those o^wrTe^hrough the in/ckHs5t>4LLow
nnnncomputer module^r
nnnnThe flow computer's computation is divided into
nnnntwo stages. First, the oil is measured with the gas 'in
nnnnsolution.' Then, three 2100-AGA modules transfer the
nnnnresults to the PLC data memory where the gas amount
nnnnis subtracted frc/no t/e on volume whicTuis supplied bV/
nnnnthe module. This is accomplished by using a correlation
nnnninvolving the gas density (also supplied by the module),
nnnnoil density, pressure and temperature.
nnnn^ l \ Uo\tinued
nnnnASIA PACIFIC
nnnnAFRICA
nnnnEUROPE
nnnnMIDDLE EAST
nnnnLATIN AMERICA
nnnnNORTH AMERICA
"