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PROCESS CONTROL AND INFORMATION SYSTEMSSPECIAL REPORT

otivas Norco refinery produces about 7 million gal-lons of gasoline on a typical day for New Orleans andnearby states, ranking it among the largest refineries

in the world. Blending dynamically requires the refinery to beon spec with all blending components 24 / 7. Several years ago,Norco management realized that the modernization of instru-mentation and controls had not kept pace with other improve-ments to key units at the refinery. Management was determinedto increase the refinery reliability by using predictive monitoringof the plant and its assets, avoiding upsets, improving instru-ment reliability, and improving maintenance and operationseffectiveness.

Norco selected an advanced digital plant architecture andmain automation contractor for the modernization whichproved highly successful. The refinery has moved away fromreactive maintenance and toward preventive maintenance usingdiagnostics and predictive maintenance to, for example, deter-mine before a turnaround what valves need to be pulled forrepair. This past year the Norco refinery delivered its best everrefinery reliability, operational performance and utilization, andthe benefits that were achieved from reinstrumentation haveplayed a key role in these successes.

Motiva Enterprises LLC is an oil refining, lubricants andretail business operation owned by Shell and Saudi Refining Inc.Motivas refinery in Norco, Louisiana, processes 10.1 milliongallons of crude and produces 7.1 million gallons of gasoline,1.9 million gallons of jet fuel, 2.1 million gallons of diesel fueland 1,000 tons of coke daily. Motivas primary customer is theNew Orleans market, but it also serves nearby states includingGeorgia and Florida.

The distilling unit (DU) takes in crude oil and distills itto lighter fractions that undergo further processing in otherunits, and heavier fractions that are sent to the residual cata-lytic cracking unit (RCCU) and hydrocracking unit (HCU)as feedstocks. The RCCU uses heat and catalyst to convertheavy oils into more valuable lower-molecular-weight productssuch as propylene, butylene, gasoline and distillates. The HCUconverts heavier fractions from the DU to gasoline and lighterbyproducts in a hydrogen-rich atmosphere. The coker thermallycracks heavy oils to produce lighter hydrocarbons and coke.The alkylation and MTBE treaters produce the gasoline addi-tives needed for boosting octane. The kerosine treater upgradeskerosine for jet fuel usage.

Improving refinery reliability,performance and utilizationA new digital control system incorporating fieldbus providedsubstantial benefits

J. FUNKHOUSER, * Motiva Norco Refinery, Norco, Louisiana and F. MANLEY, Emerson Process Management, Austin, Texas

M

* Jeff Funkhouser is operations manager at Motiva and Fred Manley is director,global rening, at Emerson.

Motivas Norco, Louisiana, refinery produces 7 milliongallons of gasoline per day.

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October 2007 issue, pgs 7376Used with permission.www.HydrocarbonProcessing.com

Originally appeared in:Article copyright 2007 by Gulf Publishing Company. All rightsreserved. Not to be distributed in electronic or printed form, or postedon a Website, without express written permission of copyright holder.

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Challenges faced by Norco. One of the greatest challengesfaced by Motiva is the need to increase crude flexibility. In thepast, the refinery processed primarily sweet crudes from the Gulfof Mexico, but is increasingly being forced to rely upon moresour crudes, particularly from Africa. Adding to the challengeis the practice at Motiva Norco of blending finished productdirectly to pipeline. As an inline blender of finished products,the Norco refinery has no shipping tanks. Blending dynamicallymakes it necessary to be on spec with all the blending compo-nents. There is no room for mistakes. Finally, with demand near-ing, and in some cases exceeding, refining capacity, the Norcorefinery faces the challenge of maintaining reliable operations toavoid interruptions in supply to major markets.

Norco management recognized that the only way to meetthese challenges is through the smart application of technologyto achieve economical, reliable and productive operations. Abroad cut is no longer acceptable; rather, excellence is required24 hr a day, 7 days a week. Several years ago Norco manage-ment looked at how to utilize this refinery asset more fully anddetermined that it was well positioned from a configurationstandpoint without a lot of major capital investment needs. Butthere was one major exception. The instrumentation was notup to the challenge of the 21st century. Cokers, reformers andhydrotreaters were running with antiquated pneumatic controls.Increased sulfur content in crude demanded better hydrotreaterand coker performance. MTBE removal as an additive placedincreased demands on the reformer. All this resulted in poorreliability and frequent shutdowns.

Initiating a modernization project. Refinery manage-ment initiated a modernization project to improve equipmentreliability, avoid abnormal situations, speed response to upsetsand improve maintenance practices. Norco selected a digitalplant architecture with a network of intelligent field devicesthat provide advanced diagnostic information about themselvesand the process. The architecture also includes an automationsystem that is built for busses and fully supports Ffieldbus and other bus technologies, and software that deliversinformation wherever its neededfrom the control room to themaintenance shop to engineering and management offices.

Centralized control room plays key role. The proj-ect scope encompassed eight major process units, 6,000 I/O

points and 636 control valves, and consolidated five separatecontrol rooms into one centralized, integrated control room.The new central control room was a focal point of the project.The design radiates from the operator outward, increasing hisor her awareness. An overview layer is always present on the big

wall screens, giving the operators a birds eye view of the entireplant. When an alarm occurs, operators can quickly drill downto get full details on the problem as well as the ability to takeaction to correct it.

Norcos workforce, and changes in its work processes, havebeen the key to the success of the project. Motiva Norco man-agement understands the need to invest in people to take fulladvantage of technology. For example, the new control roomincludes training simulators for each of the refinerys units that

were upgraded. Norco personnel have been trained by standardtraining courses and by using the products in the field.

The digital architecture includes digital automation systemsand asset optimization software that have been used exten-sively to improve reliability and control performance. Predictivecapabilities have been improved so that maintenance can beperformed proactively. Communications have been stream-lined which reduces response times. Maintenance direction andfocus have been improved, empowering the workforce to ownreliability. Much more information is available from each unitthan in the past through the use of the new digital architecture.Predictive diagnostics make it possible to identify and correctproblems in the instrumentation or other equipment beforethey actually become a problem in the field. In this way the newinstrumentation improves reliability by avoiding problems thatotherwise might force the plant to be shut down.

Reducing problem diagnosis time. The new instrumen-tation greatly reduces the time required to diagnose problems.For example, in the past if an operator noticed a problem on aunit at night he or she would call an engineer at home and askhim or her to come into the plant to diagnose the problem.

Motivas new control room was a focal point of themodernization project.

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Intelligent digital valve controllers provide diagnostics tospeed repairs.

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Two or three hours later the engineer would be at the site ofthe problem and could begin troubleshooting. Now, the opera-tor can drill down from the control room and obtain quite adetailed picture of the situation. The operator may be able tounderstand and solve the problem without the engineers input.If the engineer is needed, the operator can call on the phoneand the engineer can immediately log into the instrument to see

the same readings that the operator is seeing. In most cases, theengineer can diagnose the problem without ever coming to theplant. The result is that the problem can be fixed in much lesstime. This helps avoid upsets.

Improvements in the processing units translate into overalloperational excellence at the Norco refinery. In one typicalexample, a valve positioner had been physically damaged byconstruction work. Every control valve in the HCU has beencompletely outfitted with digital valve controllers (DVCs). TheDVCs have a feature called pressure control mode that essen-tially memorizes the pressure that has to be put on the actuatorto move the valve. The DVCs also have sensors so if they losetravel feedback they will automatically switch over to pressurecontrol mode and continue to control the process. About amonth after starting up the HCU, the operator got a travelersensor failure alarm but an intelligent DVC had previously iden-tified the problem and provided diagnostics that were used tospeed repairs. Maintenance was already on the way to the field tosolve the problem before the operator could put a request in.

Substantial improvement in reliability. Operations,maintenance and management all like working with the newdigital plant architecture. Troubleshooting is more effective andit occurs before it affects operation. Engineering changes areeasier to make and so improvement ideas tend to be implementedinstead of being put on a backlog. The result has been a sub-stantial improvement in reliabilitythe main driver of refineryoperations. In a world where the global demand for fuel is almostequal to the global capacity, any time that a plant is down its aproblem. So reliability is the most important thing in petroleumindustries.

The teamwork and the cooperation between the Norco projectteam and the automation supplier has been extraordinary. They

worked together 24 hr a day, 7 days a week to resolve any issuesthat arose. Problems were quickly and efficiently resolved with-out Norco management ever having to become involved. At theend of the day there are a lot of things going on in the plant thatrequire the attention of highly skilled professionals. When those

folks work together in a way that is seamless from a managementperspective, the refinerys needs are well-served.

Dramatic improvements in refinery performance. The reinstrumentation project was about achieving our currentand future business goals and it has accomplished exactly that.Norco is currently turning in its best ever reliability utiliza-tion year on record. This improvement has provided increasedoutput without adding new units and the huge investment andlead-time that would have been required. Based on Motivasglobal standards, Norco is tracking among the best in class.These achievements have results from the refinerys strategicinvestment in reliable technology, the skills of our people andthe development of a platform of work processes that run 24hr a day.

Norco managers are proud that with a relatively small amountof capital investment we have created what we refer to as a gaso-line machine, capable of reliably meeting the markets needs.The refinery is shipping its products dynamically up pipelinesthroughout the Southeast and the East Coast. Recently, therefinery supplied the city of Atlanta on a weekend when it wasnearly out of premium gasoline, and others were unable todeliver. Earlier this year on a holiday weekend the refinery didthe same thing for markets around Washington, DC, when they

were nearly out. In both cases, the refinery met the specs, by the way, without MTBE.

Through its investment in smart technology, the refineryis able to blend gasoline 24 hr a day with minimal downtime.The Norco refinery is an asset that is ready to meet the needsof the country and its stakeholders by reliably, efficiently andsafely delivering products in the 21st century. HP

Article copyright 2007 by Gulf Publishing Company. All rights reserved. Printed in U.S.A.Not to be distributed in electronic or printed form, or posted on a Website, without express written permission of copyright holder.

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