FCW is completely integrated into the ICSS both at the programming level and at the user interface level. In most cases it does not require additional hardware.
However FCW uses PCS additional resources in term of number of displays, database size and calculation capability of the controllers.
This chapter lists the additional resources required for FCW implementation into the PCS.
4.2.1 ICSS classical architecture diagram
DRILLING PLATFORM (DP3) DRILLING PLATFORM (DP2) DRILLING PLATFORM (DP1)
System Bus
PSS
Controllers ESD Local Operator
workstation(s)
PCS Controllers
PRODUCTION PLATFORM
System Bus
PSS
Controllers ESD Fire & Gas Local Operator
workstations
PCS Controllers
PDMS Communication Bus
See GS EP TEL 170
N
Monowell and Multiwell FCW modules are implemented in a dedicated PCS controller
Multifield FCW module is
implemented in a dedicated PCS controller
4.2.2 Functions splitting by subsystems
4.2.3 FCW modules sizing
4.2.3.1 Supervision and control views
The number of views required for the FCW control of wells is estimated according to the table given in §3.7.1 (views per module).
Site Subsystem Impact of the FCW for the subsystem
ESD None PSS None
PCS FCW Multifield algorithm
HMI
Control views and parameters setting views for : - All the satellite platforms Monowell.
- All the satellite platforms Mutiwell.
- Multifield displays.
According to the tables given on the following paragraphs.
On the central
- the SSV and SDV header gas-lift status.
- the SD bar status
- manage the Wing Valve and the SDV gas-lift safety command
PCS
Control displays and parameters setting displays for - All the satellite platforms Monowell.
- All the satellite platforms Mutiwell.
- Multifield displays.
4.2.3.2 System database sizing
FCW implementation involves the creation of all the following parameters.
Table of the supervised variables for an eruptive well.
Parameters Well control Type
mono multi Commands Status Alarms Total
Real 32 8 40
Integer (or
enumerate) 3 0 6 5 14
Alarm 6 6
Read/write Read and Write Read only 60
Table of the supervised variables for a gas-lifted well.
Parameters Well control Type
mono multi Commands Status Alarms Total
Real 39 12 51
Integer (or
enumerate) 3 1 8 5 17
Alarm 2 2
Read/write Read and Write Read only 70
Table of the supervised variables for a PCP or ESP well.
Parameters Well control Type
mono multi Commands Status Alarms Total
Real 42 12 54
Integer (or
enumerate) 0 0 8 5 13
Alarm 10 10
Read/write Read and Write Read only 77
4.2.4 Requirements
4.2.4.1 ICSS performances requirements
The following table defines the ICSS cycle and response time for FCW algorithms treatment.
Level Response time Value
Time for mmeasurements update in the controllers. ≤ 1 S Cycle time for the execution of the algorithms off all the wells. ≤ 1 S Monowell
Time for sequences realignment upon safety trip. ≤ 2 S
Cycle time for the execution of the algorithm ≤ 10 S Response time between a process limitation high threshold detection and the
first load shedding. ≤ 20 S
MULTIWELL
Minimum time between two load shedding. ≥ 10 S
Multifield Response time between a process limitation high threshold detection and the
first action ≤ 30 S
Displays Control or strategy display refreshment time including the update of all the
displayed variables. ≤ 10 S
4.2.4.2 Functionalities PDMS
The system must allow the recording and recovery in a trend form Y = f (T) of all the measurements of all the wells with the following minimal characteristics:
• Number of trends per display: 6 minimum (for a good analysis of the process)
• Sampling frequency: 30 to 60 seconds
• Recording duration: 30 days
• Trend usual time range: 12 hours
• Mobile marker allowing an easy reading of a value at a given time.
• Time scale backward and forward scan, backward scan to a specified date.
• Forward and backward zoom for both scales (time and Y), Y Auto scale.
• Color printing of the trends must be possible without a saturation of the background.
Important note: on each site the well performance engineer must have a supervising workstation.
Online help
• A HTML file is available with the Monowell parameters and command descriptions. This file is accessible from the control view.
• Some HMI supervisors are able to deal with conceptual help that can be used for each variable of the displays or for keywords research into the HTML file. This functionality should be implemented if possible.
Data export
The system shall allow import / export of the FCW settings into Excel files. The aim is to be able to treat these data on a desktop (or laptop) computer.
4.2.4.3 Data safety
• The write access to the different data is protected by a user identification system.
• The production superintendent (or the well performance) has a write access to the Monowell / Multiwell parameters.
• FCW settings must be backed-up into the controller memory with a long live time battery (48V back-up power or other). FCW settings are not back-up in the workstation (neither client nor server).
A file back-up of the controller memory must be implemented in case of replacement of the controller processing unit card.
4.2.4.4 Availability
Safety level of the PCS controller where FCW is implemented: no SIL level required.
In the following table, criticality is related to the availability of the installation and not to the security.
Critical: a system unavailability that partially or totally stops the installation (with or without FCW).
Non critical: a low probability and short duration system unavailability that has a marginal incidence on the production.
Subsystem \ criticality
Critical Non Critical Guide line to be observed
PCS controller *
Power supply back-up
PCS faults (watch dog) are monitor by the PSS that may lead to a safety trip.
For a remote site (satellite platform or cluster) the controller must be local and completely autonomous.
Operator workstation *
None of the control logic is implemented into the workstation (client or server). One or all the workstation can be power down without any perturbation on the process.
PDMS *
One (or better two) of the workstations forward the measurement to the PDMS with a periodicity of around 10 s. In case off communication shut down the data are temporary stored in the memory of the workstation.
Values are time-stamped at the source.
Telecommunication system between the
central site and the remote site. * FCW is autonomous and a stop of the remote site is not necessary in case of communication shut down.
Telecommunication system between the
controllers of the same site. * A communication shut down between the FCW PCS and other controllers does not stop the wells process.
Instrumentation * FCW algorithms are able to manage an invalidity or a maintenance inhibition of the sensors