Q&A and Technology Forum - refinery planning … PRODUCTION ACCOUNTING AT FRONTIER'S CHEYENNE, WY...

Q&A and Technology

Forum

Plant Automation & Decision Support Session

2008

DAILY PRODUCTION ACCOUNTING AT DAILY PRODUCTION ACCOUNTING AT FRONTIER'S CHEYENNE, WY REFINERYFRONTIER'S CHEYENNE, WY REFINERY

Tina Geyer, Tina Geyer, Frontier Refining Inc., Cheyenne Refinery, WYFrontier Refining Inc., Cheyenne Refinery, WY

Marcela BrinaMarcela BrinaSoteicaSoteica Ideas & Technology, L.L.C.Ideas & Technology, L.L.C.

October 2008October 2008

2008 Q&A andTechnology Forum


Refinery wide mass balance is an achievable and worthwhile goal.

It is the basis of any loss control initiative.




Cheyenne Refinery embarked in a refinery-wide mass balance initiative in 2003.

The project took approximately a year from the kick-off meeting to the daily use of the new production accounting system.

Soteica's S-TMS production accounting system is now used for solving the daily mass balance.

Soteica LLC provided S-TMS software and implemented the production accounting system.

FRONTIER'S CHEYENNE, WY FRONTIER'S CHEYENNE, WY REFINERYREFINERY

Permitted crude capacity of 52,000 bbl/day.

Frontier market’s its refined products primarily in the eastern slope of the Rocky Mountain region (eastern Colorado including the Denver metropolitan area and eastern Wyoming).

Our coking unit allows the refinery to process up to 100% heavy crude oil for use as a feedstock.

Historically, heavy crude oil has accounted for 80% or more of the Cheyenne refinery's crude oil charge.

Product mix: gasoline (41%), diesel fuel (30%) and asphalt and other refined petroleum products (29%).

Crude oil is purchased from local producers and also imported via the Express Pipeline from Canada.


Soteicaideas &technology

Since 1985, Process Engineering Consulting Company

Projects around the world

Offices in Barcelona, Houston, Mexico, Buenos Aires and São Paulo

Full suite of local services:

Implementation

Technology transfer

Full local support

Continuous improvement program

Soteica products:

Visual MESA : Energy Management

S-TMS: Production Accounting

S-SOM: Refinery Scheduling

S-OTS: Operator Training


PRODUCTION ACCOUNTING PROJECT AT PRODUCTION ACCOUNTING PROJECT AT FRONTIER'S CHEYENNE, WY REFINERYFRONTIER'S CHEYENNE, WY REFINERY


Key factors for project success:

Support of Frontier’s management team.

Active collaboration of Soteica's and Frontier's project managers, both in the implementation stages and during the operation.



Key factors (cont.):Mass balance model with the appropriate level of detail to provide sufficient cross-checking and redundancy between measurements.

Analysis is done simultaneously of the whole refinery on a tank by tank and unit by unit level of detail instead of on a product by product basis.

S-TMS is highly integrated with other Frontier systems, thus minimizing the manual data entry efforts and errors.

PRODUCTION ACCOUNTING PROJECT PRODUCTION ACCOUNTING PROJECT AT FRONTIER'S CHEYENNE, WY AT FRONTIER'S CHEYENNE, WY REFINERYREFINERY


Cheyenne Refinery model includes:Processing units as black boxes.

Point of receipt and shipments on site as boundary limits.Tank farm is modeled tank by tank.Other inventories such as the coke pile, sulfur inventory, and

loaded but not shipped railcars.Generation and consumption of fuel gas, fuel oil, natural gas

and the sulphur and hydrogen produced and consumed.

The model is easily maintained and adapted to plant changes (such as new meters, new tanks) by the Frontier Yield Analyst.



S-TMS production accounting system is highly integrated with other Frontier systems:

Retrieves information from the data historian.Imports information from the truck dock system.Imports information from the weigh scale system.Exports information to the in-house ERP system that resides in the corporate offices in Denver.



Daily reconciliation

Initially, an external reconciliation engine was used, but it was later upgrade to the S-TMS embedded reconciliation engine.

This change highly facilitated the model operation and maintenance.

Crude composition is also calculated on a daily basis.



Daily accountingThe role of production accounting, assisted by process engineering, is to find sources of error and work in a continuous improvement mode.

The reporting is the common information platform for the refinery both as a whole as well as on a unit by unit basis.

Production accounting cannot be done “automagically”. The accounting and analysis phase is done on a daily basis and with human intervention.

S-TMS PRODUCTION ACCOUNTING SYSTEMDESCRIPTION

S-TMS is an application that allows production accountants to model inventories and material movements typical of the process industry.

S-TMS web client provides screens to show all captured data (both manual and from other systems).

S-TMS can import and/or export information to/from other systems.


S-TMS has an embedded algorithm engine to minimize the mass balance statistical errors.

Two reconciliation methods available:Traditional gross error identification method.

Successive error identification and simultaneous compensation method.

If multiple gross errors are present in the data (most frequent case), the traditional gross error identification method will spread the error in a way that makes it very difficult to detect its location.S-TMS implements a successive error identification and simultaneous compensation method which allows for a more precise gross error location.






S-TMS:Calculates inventories, flows and movement quantities.Keeps track of material changes in tanks (Reclassifications / Regrading).Calculates tank composition (optional Composition tracking module).Tracks planning information (optional Planning tracking module).Has a complete set of standard reports.



S-TMS PRODUCTION ACCOUNTING SYSTEM




S-TMS Results Analyzer client graphically displays the model and the reconciliation results.

S-TMS MS-Excel Add-in is used for data export to Excel.

S-TMS Report designer is used for the creation of new reports and modification and customization of existing reports.


Results analyzer



Excel add-in



Report designer2008 Q&A andTechnology Forum


PRODUCTION ACCOUNTING PRODUCTION ACCOUNTING PROJECTPROJECTBENEFITSBENEFITS

Benefits during the model building phase:

The project team gained a detailed knowledge of the plants operations and tank farm movements.

All existing accounting procedures were reviewed and improved in order to gather the daily information required to perform the mass balance.


REFINERY DAILY PRODUCTION REFINERY DAILY PRODUCTION ACCOUNTINGACCOUNTINGBENEFITSBENEFITS

Daily use benefits:

As a result of doing daily mass balances, S-TMS has helped Frontier resolve many balancing issues with ease that may have been difficult to find without a good gross error analysis tool.


Valve leak:Frontier had a valve that failed on a coker charge tank which allowed product to leak to an asphalt tank. This tank was out of service, therefore, not gauged on a daily basis.

The Result Analyzer helped find the error in an aggressive manner alleviated the possibility of a tank spill and selling out-of-spec product.



Tank leak:Frontier had a sales tank that developed an underground leak. This was found through an investigation which was launched after several consecutive days of reported losses.The tank was quickly taken out of service and repaired, possibly saving thousands of barrels of finished product.



Missing/Incorrect Movements:A receipt or shipment will occasionally get overlooked, such as a missing pipeline shipment, or a receipt recorded with an incorrect product code.

With the use of the Result Analyzer and the product balance report, errors such as this are easy to identify.



Flow meters recalibration:Flow meter inaccuracies are easily identified with product balance and unit yield reports. Correcting these meters improves the mass balance on a continuous basis.

Typically, yielding will discover a meter discrepancy before operations notices the error.



Crude composition tracking:The crude composition report has helped Planning with crude purchases, setting unit charge rates and inventory levels.

Frontier uses their crude tanks as slop tanks and it is important to identify the intermediate stock in these tanks to set charge rates and to carry those inventories to the month-end financials.



Reports used by many areas of the refinery:With the market getting tighter there is a lot of emphasis on having an accurate mass balance. There are several reports that help Frontier identify areas that need attention.

Process Engineering and Planning works closely with Operations and Yielding to have meters recalibrated, orifice plates checked, and factors verified.

The Refinery Manager closely watches the monthly loss report and gives direction based on these results.



It is very difficult to put a typical dollar amount on the benefits, because once the problem is discovered and corrected, it can produce a positive or negative monetary impact.

The most important benefit in all cases, is the improved process knowledge and the certainty that proper accounting is being performed.



PRODUCTION ACCOUNTING PROJECTCONCLUSIONS

A refinery wide mass balance production accounting system is the first step towards a loss control initiative.

It provides useful information for the continuous improvement of the overall measurement system and generates widely accepted results used by all refinery area personnel.


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