Evolving software tools to manage gas transportation business.
Since natural gas is going to be the fuel of the future, the gas pipeline networks are expanding on a large scale. To cater to a fluctuating demand/supply situation, the existing pipeline networks are being interconnected so that excess demand in one network can be met with excess capacity available in other network. Thus managing interconnected multiple pipeline networks having multiple gas sources and multiple shippers is becoming a challenging assignment.
To have a cutting edge over the competition, gas transporter should be equipped with software tools in order to serve the interests of gas consumers, shippers and suppliers in a transparent, reliable and economic fashion without hassle. For this, it is necessary that the gas transporter provides an on-line common platform for interaction among the gas consumers, shippers, suppliers and transporter. Using the on-line system, they can put forth their requirements and constraints to address each other's interests on a short term as well as long-term basis.
Gas Management System (GMS), implemented by M/s Telvent, Canada, provides software tools for integrating all the shippers, suppliers, customers, and transporter for better coordination and total transparency. Supervisory Control and Data Acquisition System (SCADA) provides real-time monitoring and control of pipeline facilities from a central control room. Pipeline (Modeling) Application Software provides tools for economic, reliable and safe operation of the pipeline networks.
GMS facilitates in contract management, long-term gas scheduling (annual program), nominations by buyers and approval of nominations by sellers. Also gas allocation to shippers at redelivery stations where customers purchase gas from multiple shippers and at delivery stations where gas is supplied to multiple shippers, gas reconciliation in interconnected and independent P/L networks, management of unaccounted gas (Transportation Loss/Gain), gas reconciliation for shippers, customers & suppliers, annual take or pay obligation for gas sale/purchase contracts, annual ship or pay obligation for transportation contracts, e-ticketing, invoicing etc.
Pipeline (Modeling) Application Software models the pipeline network and associated facilities in real time and assists the gas dispatcher in safe, economic and reliable operations of the pipeline. The APPS system provided various software tools for (i) Drawing pressure, temperature, flow profiles; (ii) Leak detection and location; (iii) Inventory analysis; (iv) Gas composition tracking; (v) Scrapper tracking; (vi) Predicting future operating conditions using automatic projection of current pipeline operation in future (Look Ahead); (vii) Operations planning and contingency analysis using Predictive Module; (viii) Compressor fuel optimization: and (ix) Training gas dispatchers using training simulator.
Integration of GMS, APPS and SCADA systems: Integration of GMS, APPS and SCADA systems provides a complete suit of software tools to manage the gas business. GMS, being WEB enabled, can be accessed through the Internet for day-to-day business activities by operations, marketing, and finance personnel of consumers, shippers, suppliers and transporter
Daily nominations can be entered directly online. Current hydraulic state of pipeline and real-time sale/purchase figures (Gas Supplied in Volume and Calorific Value) are available through the SCADA system. Using the APPS tools, the transporter can analyze the operational feasibility of carrying the gas as per received nominations and adjust the nominations before approving the daily nominations. The approved nominations are instantaneously known online to the consumers, shippers, suppliers and transporter to plan their daily operations.
If the GMS system can access data from the SCADA system online, then the consumers, shippers and suppliers can see their current position at any time and plan their operations to avoid any contractual violation.
In this way, GMS can help consumers, shippers, suppliers and transporter benefit, fight from gas nominations to billing, as explained below:
Contract management: The shipper enters into long-term gas sales contract with the consumers, purchase contract with suppliers and transportation contract with the gas transporter. However, it is the gas transporter, who lifts the gas from the supplier and delivers it to the consumer on behalf of the shipper. Contract Management tool helps in defining the various details of these business contracts and the organizations in software database and ensuring running of the contracts without violation of any contract provision.
Annual gas forecasting/scheduling: While the contract provides guidelines for gas sale/purchase/transportation over a long period, the actual requirement for each year is finalized before start of the year, based on the anticipated demand/supply situation and outstanding position of each company. Annual gas requirement (further broken down to quarterly, monthly, weekly and daily) can be proposed and finalized among the customers and shippers, shippers and suppliers, transporter and shippers using the GMS system.
The annual gas scheduling involves finalization of Adjusted Annual Contracted Quantity (AACQ) and Agreed Makeup Gas for the next year. The breakup of AACQ consists of ACQ, Make-good gas, Restoration gas, Downward flexibility, Upward flexibility, etc. GMS keeps track of all these quantities and assists the companies in finalization of AACQ, plus Makeup gas within contractual provisions.
Nominations approval: Similar to annual gas scheduling, the GMS provides facility for daily gas nominations by customers to shippers, shippers to suppliers, and shippers to transporter and approval by the respective agency. The daily nominations can also be changed during the day. The approved daily nominations are instantaneously known online to the consumers, shippers, suppliers and transporter to determine the quantity of gas to be purchased/transported.
Using the online gas delivery figures at each metering station, the gas dispatcher can determine the restrictions to be imposed based on the approved daily nominations.
Gas allocations: At the delivery or redelivery stations, gas is measured by single Flow Computer (FC). Through single FC, the gas is supplied or received by multiple shippers. The GMS has a library of multiple allocation rules e.g. Pro-rata, Rank, Percentage, Swing, etc. For each delivery/redelivery station, the appropriate allocation rule can be selected for a specific period from the library.
Short supply breakup: If the gas supplied at any redelivery or delivery station is less than the sum of approved daily nominations for the station, the GMS calculates breakup for each shipper of short supply resulting due to force majeure conditions, shipper's failure, transporter's failure, supplier's failure, off-spec gas, planned maintenance, etc. This helps in fixing the responsibility for short supply so that contractual provisions can be handled.
Gas reconciliation for transporter, shippers and customers: Gas transporter owns the pipeline network and has the transportation contract with the shippers to lift the gas from the supplier and deliver the gas to the consumer on behalf of the shippers. Depending upon each transportation contract, transportation loss could be included in the lump sum transportation charges or paid separately, depending upon actual transportation loss. Similarly, the initial line fill quantity of each shipper, allowable minimum and maximum gas inventory in the pipeline, are also defined in the transportation contract.
Therefore, it is essential that transportation losses for each shipper, and breakup of line pack owned by each shipper and the transporter, are calculated on a daily basis. In case the transportation losses are included in the lump sum transportation charges, the transportation losses for that shipper are to be borne by the transporter and the transporter has to replenish the lost gas by purchasing it from some supplier.
The GMS carries out the gas reconciliation for the independent as well as interconnected pipeline networks. The gas reconciliation consists of details like opening stock of shippers and transporter, gas purchased by the shippers and transporter from the suppliers (delivery station details i.e. allocations, shortfall breakup), gas sold to each customer by the shippers (redelivery station details i.e. allocations, shortfall breakup, overdraws, etc.), closing stock of shippers and transporter, change in physical line pack, transportation loss (unaccounted gas), etc.
Similarly, the GMS carries out the gas reconciliation for customers and suppliers, which consists of the details like gas purchased/sold by the shippers (allocations, shortfall breakup, overdraws, etc.).
GMS can also handle the transfer of excess gas to other shippers having a short supply of gas to overcome his TOPDQ/SOPDQ (take-or-pay/ship-or-pay daily quantity) obligations.
Annual Take-or-Pay/Ship-or-Pay Obligations: At the end of the year, it is required to calculate the Annual Take or Pay Quantity (ATOPQ) between shippers and customers, shippers and suppliers (Annual Ship or Pay Quantity in case of transportation contract) based on the AACQ, force majeures, off-spec quantities, etc.
Considering the ATOPQ/ASOPQ and actual delivery/redelivery figures, Annual Take-or-Pay Deficiency Quantity (ATOPDQ) quantities (ASOPDQ in case of transportation contract) need to be calculated for preparing the ATOPQ/ASOPQ invoices.
GMS calculates the ATOPDQ/ASOPDQ quantities at the end of the year automatically as well as all the required figures available in the GMS on a daily basis.
Calculation of outstanding DFQ, FMDQ and TOPDQ/SOPDQ: The Downward Flexibility Quantity (DFQ), Force Majeure Deficiency Quantity (FMDQ), and TOPDQ/SOPDQ quantities are carried forward to the next year after adjustment of appropriated make-good gas, restoration gas, and makeup gas in the current year. GMS calculates all these quantities at the end of the year so that AACQ for the next year can be finalized.
e-ticketing and invoicing: Earlier gas ticketing was based on signing of flow computer (FC) reading at the end of the day by the seller and purchaser, respectively. In case of purchase of gas by multiple shippers from a supplier at the same delivery station through single FC, ticketing can be done only after the allocation of gas. Similarly, ticketing in case of purchase of gas by a consumer from multiple shippers at the same redelivery station through single FC can be done only after the allocation.
GMS generates daily gas purchased/sold reports for each station based on the allocated quantities, which can be signed by both seller and purchaser electronically as GMS is accessible to all the agencies through the Internet. Moreover, an invoice can be generated through GMS and sent electronically via email or accessed through the Internet).
Through proper authorization by the system administrator, each user can access only selected functions and stations which are relevant to the user, thus providing confidentiality and security of data.
S.K. Agrawal, Chief Manager, GAIL (India) Ltd, India
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|Comment:||Evolving software tools to manage gas transportation business.|
|Publication:||Pipeline & Gas Journal|
|Date:||Feb 1, 2006|
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