Dr Guy Vachon, Baker Oil Tools

INTELLIGENT WELL TECHNOLO-GY made significant progress during2003. The number of installed Baker OilTools systems in 2003 was almost equalto the total accumulated number ofinstallations in the previous four years.Several new milestones were reachedincluding installation of an all-electricintelligent well system in a subsea deep-water application and installation ofhydraulic choking valves.

There has been an increased interest inand use of three and four zone intelli-gent completions and applications oninjectors as well as broader considera-tion of ESP applications. The industry iswitnessing significant changes in atti-tude towards use of this technology. Inthe past operators had studied thepotential benefits. A few have been ten-tatively testing the technology in orderto gain first hand experience regardingthe risks and issues in the context ofintelligent wells. The acceleration inactivity last year resulted in two impor-tant trends. Emboldened by recent suc-cesses and rising reliability rates, moreoperators are trying their own “experi-ments”.

More importantly, those with experiencein the technology are finding templateapplications with proven economicadvantage. These applications are find-ing their way to standard completionpractice.

Another interesting fact is that two-thirds of the producers are artificiallylifted wells operating on borderline eco-nomics. The economic successes ofintelligent well technology applied tothese wells immediately crushed themyth that intelligent well technology canonly be economically justified in high-end applications.

Another hint to this is the observed dis-tribution between land wells, platformwells and subsea wells; two land wellsand two platform wells have beeninstalled for every subsea well.

I M P R O V E D R E L I A B I L I T Y

Intelligent well technology reliabilityremains a concern with most operatorsbut the facts prove that the technology is

a relatively safe investment. As of thiswriting, Baker Oil Tools installed a totalof 38 hydraulic sleeves and electricvalves in 27 intelligent well systems ofvarying complexities. The total accumu-lated days of operation have been inexcess of 35 years and none of thehydraulicly operated sleeves or electricly operated valves have failed to date.

However, intelligent well systemsinclude the zonal isolation methods,hydraulic and electric control lines, con-nectors, expansion joints, downholewet-connectors and other accessoriesthat contribute to the overall systemreliability.

The overall performance of these com-ponents is again much higher than mostoperators expect. For example, the com-pany has recorded zero failed electric orhydraulic connectors out of more than250 installed connectors. No failureshave been recorded either on any of the

above mentioned accessory componentsother than control lines.

The company recorded five failedhydraulic control lines out of almost 80hydraulic and electric lines deployed.These failures occurred during the earlystages of the technology and directedchanges in running procedures as wellas adoption of various safeguards. Thelongest recorded operation of a singlehydraulic operated valve is 3 1/2 yearsand counting.

The rapid maturing of new intelligentwell systems results from their havingbeen built on proven technology that hasbeen used for many years in safetyvalves and conventional sliding sleeves.To date, the company has run more than15,000 tubing retrievable safety valvesand almost 10,000 sliding sleeves withalmost negligible failure rates. A suc-cessful track record in intelligent welltechnology needs to be maintained asthis technology particularly is only per-ceived to be as good as its last installa-tion. Equipment design and deploymentpractices are being improved constantlyin order to stay ahead of operators’expectations.

A D J U S T A B L E C H O K E S A N D E S P S

Baker Oil Tools installed multiplehydraulic adjustable chokes under anESP in Ecuador in December 2003. Itincorporated pressure, temperature,and flow measurement devices to com-mingle and optimize production fromtwo zones. The intelligent well systemprovides full zonal control and real-timedata monitoring, thus allowing the oper-ator to monitor and optimize the pro-duction from each zone.

This intelligent well technology providesthe zonal control and real-time datarequired to adhere to governmental reg-ulations for commingling multiple zoneswhile dealing simultaneously with thedifferent characteristics of each zone tooptimize production. This system alsoeliminates the need for intrusive wellinterventions that would have been nec-essary in a conventional completion.

In order to identify a proper candidate areservoir simulation and nodal analysiswas performed to simulate the effects ofcommingling the two zones and quantify

34 D R I L L I N G C O N T R A C T O R March/April 2004

Intelligent well systems advance toward maturity

An example of a “typical” intelligent comple-tion with commingled production from twozones with adjustable chokes and artificial liftprovided by en electric submersible pump.

ESP Power Cable

ESP

HCM-AAdjustable Choke

HCM-A (Adjustable Choke-Shrouded)

Upper Sand

Lower Sand

the economic benefit. In order to maxi-mize the economic impact the overallcost to the operator had to be mini-mized. This could be accomplished byinstalling the system during theworkover of an existing completion andby utilizing as much as possible the cur-rent product offering from the comple-tion company. New product developmentrisks delays and increases costs.

In short, current products must meshwith an existing well profile. The com-pletion design and operation should beas simple as possible. For example,since the intelligent well system will beinstalled in conjunction with an ESP,retrieving it easily was a factor in thedecision making process.

The chosen well was previously pro-duced utilizing a Y-tool with the ESPhanging on the end of the tubing string.The two zones were separated by twoproduction packers with mechanicalsliding sleeves in each zone. Productionwas alternated between zones by run-ning wireline through the Y-tool to shiftthe sleeves. The main drawback to thismethod is the constant requirement forintervention to shift the sleeves and theinability to assign production to eachinterval. Intervention requires shutdown of the ESP and thus a temporaryshut down of production. So, the opera-tor assumes the costs associated withthe intervention and lost production.The installation of an intelligent wellsystem can eliminate the costs associat-ed with intervention. Permanent moni-toring equipment was installed belowthe chokes to provide valuable real-timepressure, temperature, and flow data.Pressure and temperature were provid-ed for each zone, while flow is only pro-vided for the lower zone. During thecommingled production, the flow ratefrom the lower zone can be viewed onsurface thus providing the productionallocation required.

E L E C T R I C C O M P L E T I O N

On 3 August 2003, Baker Oil Tools com-pleted the word’s first subsea, deepwa-ter all-electric intelligent completionsystem for Petrobras. The InCharge™System was installed in the 8-MLS-67HA-RJS well in 3,540 ft of water in theMarlim field in the Campos Basin. It waspermanently tied back to the Petrobras-40, the world’s largest capacity floatingproduction unit, via a 3.7 miles umbili-

cal. This installation represented theculmination of a five-year joint develop-ment project by Petrobras and Baker OilTools in association with other compa-nies. The project was launched in late1999 in pursuit of state-of-art technolo-gies designed to help Petrobras addressthe challenges of operating in waterdepths exceeding 9,000 ft.

The completion design requirements didnot anticipate more than two zone isola-tions and associated flow control. Thus,it was determined that the simplest andmost reliable way to minimize opera-tional risks would be to make theInCharge system completely independ-ent from the lower, horizontal gravelpack sand control completion, and todeploy the InCharge system completelyseparately from the sand face comple-tion. The resulting intelligent comple-tion solution consists of an IntelligentProduction Regulator (IPR) to allocateflow into the upper zone(tubing to annu-lus), with a shrouded variation of theIPR to control injection flow (tubing totubing) to the lower zone.

The intelligent completion system wassubjected to extensive, rigorous testingat all phases of development. The com-pletion design concept was reviewedand pre-qualified during factory accept-ance testing in January 2001 with an eyetoward system deployability.

Months later, the same system wasshipped to Brazil and installed into thePetrobras 8-VRG-D-RN land well inMossoro (Rio Grande do Norte State).The system was fully functional duringthe entire trial period from May 2001thru April 2002 and was remotely moni-tored and controlled from Natal via asatellite link.

In parallel all subsea interface require-ments were being checked and qualifiedas well. Petrobras had requested mini-mum additional investment in order toenable power and communicationthroughout the existing subsea infra-structure already in use (i.e., tubinghanger, tree andtree cap, running tools,service umbilical, communication umbil-ical, etc).

A set of subsea connectors (service andpermanent) was designed, tested andmanufactured to meet those require-ments. An umbilical characterizationtest was performed in the Petrobrasstorage facilities in Vitoria City (Espiri-

to Santo State), proving the InChargesurface control system’s ability to com-municate via direct umbilical controlwithout any impedance matching modi-fications (no POD requirements) overdistances in excess of 40,000 ft (12 km).

The InCharge system was deployed inJuly 2003 and commissioned in August.It is monitoring real-time measurementsof downhole pressure, temperature andflow in both the tubing and annulus. Asa result, Petrobras can selectively man-age injection flow contribution to thereservoir intervals in real time, therebyallowing continuous field optimizationin response to changing depletion condi-tions downhole.

The InCharge intelligent well technologyallows injection flow contribution to beproperly allocated; water and gasbreakthrough to be controlled; and mul-tiple target zones to be pre-completedand selectively brought on stream (orshut off at will) from the PC-based con-trol system. A remote terminal installedin Petrobras headquarters in Rio deJaneiro and linked to the platform overtheir existing IT infrastructures permitsremote monitoring and control of thecompletion.

An analysis of time devoted to theInCharge completion operation revealsthat rig time for this operation, over andabove that which would have beenrequired for conventional completionprocedures, was negligible. However,had Petrobras chosen to use their con-ventional service test string technique,rather than the intelligent completionsystem, an additional two trips wouldhave been required to perform the selec-tive injectivty testing. Thus, ultimately,using an intelligent completion systemfor this well proved to be a time saver.

S U M M A R Y

Emboldened by technical success andeconomic advantage, users of intelligentwells are pushing the technology enve-lope while increasingly adopting thesenew tool and techniques. We are observ-ing a change in attitude as intelligentwells go from the realm of science fic-tion to an accepted part of the tool boxfor the completion engineer. This changeis being brought about by solid reliabili-ty track records as well as the identifi-cation of practical and economicallyadvantageous common applications. n

March/April 2004 D R I L L I N G C O N T R A C T O R 35