Structure and functions of the ACS
The developed system relates to distributed control
systems and consists of three control layers (see structure chart
on figure 1):
Figure 1 - Structure chart of the
ACS of Northern Bulganak field with Eastern division
Layer 0 (field layer)
includes local measurement instrumentation, sensors, transducers
and actuating devices, local automation systems at ejection unit
and subsea equipment.
Layer 1 (layer of monitoring
and control hardware) is implemented on the basis of programmable
logical controller (PLC) SIMATIC S7-300 that
provides reception of information (digital and analog) about flow
of technological process, state of systems and machinery, values
of measurable parameters. The system also performs processing of
the information in accordance with specified program, generation
of commands and information transfer to layer 2.
Layer 2 (upper layer
– layer of supervisor control and processing and visualization
of technological information) is implemented on the basis of operator
and dispatcher workstations that are augmented with communications
facilities by Industrial Ethernet network.
Communication system performs data exchange between the ICS of gas
pretreatment plant (GPP) of East-Kazantyp field and the ACS of ejection
unit of Northern Bulganak field by digital channel of radio communication
with traffic-carrying capacity up to 64 kB/s. Communication system
provides reception of instructions of remote control from the GPP
and information transfer to the GPP.