GFC Components of the RealFLO™ Multi-run Gas Flow Computer Software

SP Series PLC or SS 4203 GFC Hardware Platform

RealFLO GFC software runs in all SP series controllers. Each is ideally suited to support EFM applications.

• SP32 series PLCs are high powered ten run flow computers used wherever wells are either close together, or where many runs are measured together such as at headers, gas plants, transmission stations or coal bed methane pods. The PLCs are the processor-only version and are suited for locations where local PLC control of I/O is not required. With Ethernet capability, the SP32 series PLCs are ideal candidates for LAN applications and are currently installed in several production fields that use wireless Ethernet.
• The SP350 is a well-rounded PLC with the same on board I/O complement as the SP32 series PLCs. The SP350 PLC accommodates two gas flow runs and has the same expansion capability as SP32 series PLCs.
• SP P-series PLCs offer flexible options for those applications which require a mix of analog and digital I/O coupled with multiple communication ports.
• SPLP series PLCs are ideal for applications that require low power along with a mix of analog and digital I/O and multiple communication ports.
• The SP100 PLC is a one run flow computer that is ideally suited for EFM applications requiring small amounts of I/O while maintaining custody transfer gas measurement data.
• The highly integrated SS 4203 GFC incorporates a multivariable sensor and a complete PLC. It can be used in a wide range of process control applications including well optimization, pressure control, odorant injection and more. Coupled with a second multivariable transmitter, it can be used as a two run GFC.

RealFLO Executable Code

The executable code is an executable C or C++ program. It is provided by Weatherford and is written to SP series controllers with the RealFLO configuration utility.

RealFLO Configuration Utility

The configuration utility operates on a PC running Microsoft® Windows®, and is used to download and configure the SS 4203 GFC. The configuration utility was designed in consultation with end users and consulting engineers to make commissioning a flow computer as intuitive and efficient as possible. It allows online or off-line configuration of the gas flow run operating parameters. History and event data may be uploaded from the SS 4203 GFC into CSV files and subsequently exported into CFX format for import into Flow-Cal’s® EGM software for further use and analysis with any spreadsheet or database gas measurement software. This utility offers a user-friendly environment that is intuitive for any user familiar with Windows. It also provides all the tools necessary to confirm correct operation of the SCADA system interface to the flow computations during system startup and configuration.

The configuration utility can also configure SP series controller’s operational parameters, including communication-port settings, I/O register assignment, realtime clock and DNP settings. It provides a utility to automatically scale any SP series PLC process I/O.

Custom register views can be created to display any combination of flow computer and controller I/O database registers thereby facilitating process data monitoring.

Modbus MVT Integration

The RealFLO configuration utility allows users to completely configure and calibrate any SS 4102 (or similarly mapped) MVT from within the GFC itself. This feature greatly simplifies installation and maintenance when multiple transmitters are connected to one SP series PLC. It also allows for remote re-spanning of ranges for optimal measurement without a site visit.

Automatic Audit Trail and Log Retrieval

The configuration utility’s unique scripting capability allows users to automatically retrieve all the data required by API 21.1 audit trail requirements. Scripts may be launched from an HMI or Windows scheduler with data being saved in RealFLO binary format as well as standard CSV or CFX files.

Custom C/C++ Enhancements and User Defined Events

C Function libraries are provided to allow users to extend the application for custom protocol drivers, enhanced data acquisition for pilot projects or automatic configuration of flow computer parameters on power up. With the versatility provided by C/C++, the user can add virtually any function.

TelePACE™ relay ladder logic and C/C++ programs can store custom events in the event log, along with previous and new values. This capability is particularly valuable to record special events that are not normally part of the GFC operations. Examples could include communication error events and process alarm conditions. User defined events are allocated to a specific numeric range to prevent tampering of flow computer events.