Planning and Drilling Wells in the Next Millennium

For help in preparation of this article, thanks to MarkBurgoyne, Bobbie Ireland, Joe Jacquot, Mark Lochmannand Victor Ward, GeoQuest, Houston, Texas; and YvesMorel, Dowell, Clamart, France.CemCADE, DESIGN-EXECUTE-EVALUATE, Drilling Office,DrillSAFE, Finder, GeoFrame, GeoViz, PowerPlan,PowerPulse, QLA, SideKick, TDAS (Tubular Design andAnalysis System), WellTRAK and WEST (WellboreSimulated Temperatures) are marks of Schlumberger. UNIX is a mark of X/Open Company Limited. Windows NT,Windows 95 and Windows 98 are marks of MicrosoftCorporation.

Computing technology is changing the way engineers and geoscientists work

together to plan and drill wells interactively. Project teams can now use specially

designed software to capture best practices and integrate all available data.

The results are optimized drilling and improvements in cost control, safety and efficiency.

Until recently, exploration and production (E&P)projects that led to drilling a well were viewedas a sequential series of separate tasks ratherthan as a continuum, or a smooth workflow, andseldom involved drilling engineers. Geologistsgenerated subsurface maps using formationtops picked from well logs. Geophysicistsmapped seismic data to confirm, refine orexpand the geological interpretation. Once adrilling target was selected by the geologist andgeophysicist, the location was provided to thedrilling engineer to begin planning and designingthe well. In this manner, the project was handedoff from one person to the next as tasks werecompleted without necessarily sharing the rele-vant data that supported critical interpretationsand decisions. In fact, databases were generallydiscipline-specific, incompatible and unable toshare or exchange data readily.

Procedures for interpreting well logs or seis-mic data, generating maps, performing log andengineering calculations, and planning well con-struction varied from one professional to thenext. The lack of interaction and continuityamong project participants often resulted ininterpretations and methods that were not chal-lenged or tested, and solutions that sometimesinvolved estimates and compromises rather thanrigorous technical analysis. Industry newcomersfaced a steep learning curve until they achievedsufficient training or experience to decide forthemselves how to accomplish critical, ofteninterpretive tasks correctly.

In those days, iteration and multiple sce-nario planning were not performed unless a par-ticularly costly or high-profile project wasinvolved. The lack of routine iteration was in

François ClouzeauGilles MichelDiane NeffGraham RitchieHouston, Texas, USA

Randy HansenDominic McCannSugar Land, Texas

Laurent ProuvostClamart, France

3Winter 1998

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part a consequence of the difficulty and timenecessary to revise and reproduce hand-draftedmaps and well plans. Problems may be com-pounded in the stepwise approach to projects ifthe objectives of geologists and geophysicistsdiffer from those of drilling engineers. This lackof teamwork ultimately means that reservesmay be missed because of poor collectiveunderstanding of assets and effective means ofexploiting them.

Multidisciplinary asset teams are now work-ing together more effectively to reduce cost, riskand delay in all aspects of the workflow from thebeginning of exploration projects to the end ofthe productive life of a field. This new, optimizedprocess stems from using integrated softwareand a shared database. This change parallels atrend in the industry toward increased account-ability of asset team members to manage andimprove asset value.

The increase in teamwork comes at a criticaltime. Cost is more of an issue than ever before.New discoveries are typically smaller and moresubtle. Some of the most promising environ-ments for exploration and production are harsher(deep-water and high-pressure, high-tempera-ture environments, for example). As existing oilfields mature, recovering the remaining reservesis increasingly difficult. Operators must leverageall available intellectual capital and data,whether historical or real-time, to compete withother operators and to compensate for depressedcrude oil and natural gas prices.1

Efficiency, cost control and risk reduction inall phases of the exploration and productionworkflow, but particularly those that optimize thedrilling process, have the potential to temperE&P spending. In this article, we focus on thedrilling workflow, that is, the portion of the E&Pcycle from identification of a drilling targetthrough well construction. In the drilling work-flow, technical integrity, or the use of skills in acore competence that ensures a high level of per-formance and adherence to technical standards,is achieved with the help of software applica-tions whose algorithms reflect the best industrypractices. We begin by examining a traditionaldrilling workflow and then describe how the pro-cess has been improved by using integrated soft-ware to achieve consistently sound results.

Traditional Drilling WorkflowAs the traditional drilling workflow was accom-plished through a series of disconnected steps,project participants did not benefit from sharingof data, interpretations and experiences (nextpage, top). After geologists and geophysicistsselected a target, engineers assessed the feasi-bility of drilling to it. If the target were unac-ceptable from a drilling viewpoint, time-consuming iterations to settle on a mutually sat-isfactory target ensued.

Once a satisfactory target had been identi-fied, engineers calculated pore pressures andfracture gradients to design the casing program.These calculations and designs could varywidely depending on the expertise of the engi-neer and company policies and procedures.Typically, the next step would be for engineers orservice companies to design mud and cementprograms on the basis of the operating com-pany’s requirements. The input data for thesedesigns would be given by telephone or on paperrather than electronically. Again, depending onthe companies and engineers involved, as wellas the drilling environment, engineering prac-tices varied considerably. Operations proceededonce permits were obtained and other logisticalarrangements were made.

During drilling operations, real-time datamight have consisted of a daily drilling report andmud log transmitted by fax or telephone to theoperator’s drilling department, data not necessar-ily disseminated to the project geologist, geo-physicist, petrophysicist or reservoir engineer. Ifunanticipated drilling events occurred, the pro-ject participants would share information andwork together to resolve problems, but real-timechanges involving the entire team were oftenimpractical given the time constraints and com-munication tools available. More recently, multi-disciplinary teamwork and new software toolshave demonstrated the benefits of an iterativemethod, real-time data sharing and consultationamong project team members.

Ideal Drilling WorkflowAn optimized workflow allows team membersto collaborate fully without consuming addi-tional time (next page, bottom). The success ofintegrated geological and geophysical (G&G)software in streamlining exploration hasinstilled a desire for a complementary suite ofintegrated applications to improve the drillingworkflow. Thus, the ideal process describednext assumes the use of such tools and a com-mon, shared database.

Geologists and geophysicists select adrilling target, update their interpretations andvisualize the proposed well trajectory with G&Ginterpretation tools. Engineers select a surfaceor kickoff location using geological data andemploy drilling engineering tools to design theoptimal well path to satisfy drilling constraints.Because these processes occur simultaneouslyand data and interpretations are shared amongthe team members, iterations between geolo-gists, geophysicists and engineers in selectingtarget and surface locations are fewer andfaster than before.

Once the surface location and trajectory havebeen decided, the well prognosis for the litho-logic column, pore pressure and fracture pressureare determined. This might also require iterationsof the surface location and trajectory to avoiddrilling hazards such as shallow gas or overpres-sured zones. Next, the engineer designs the cas-ing program on the basis of geologicalinterpretations and offset well information.Service companies can then assist the engineerwith the appropriate drilling mud program,cementing program and other well constructionservices. At the end of the planning phase, theoperator applies for permits and makes logisticalarrangements to commence drilling.

It is during drilling operations that an idealworkflow scenario allows the operator to reapthe considerable benefits of data sharing and col-laboration among the team members. Real-timeupdates while drilling help optimize operations,avoid hazards and anticipate problems as theentire team works together sharing information.New real-time data are generated and input intothe database in the appropriate format to updateengineering calculations, so engineers need notreenter data into different applications at the riskof data entry errors. As experience grows andhistorical data accumulate in the database, theneeds and abilities of geologists, geophysicistsand drilling engineers will be understood betterfrom the broader perspective of a shareddatabase. Operations can proceed more effi-ciently and at lower cost and risk.

1. Close DA and Stelly OV: “New Information SystemsPromise the Benefits of the Information Age to theDrilling Industry,” paper IADC/SPE 39331, presented atthe IADC/SPE Drilling Conference, Dallas, Texas, USA,March 3-6, 1998.

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Engineeringdatabase

Geological andgeophysicaldatabase

Optimize welldesign

Engineering

Discuss well plan; reiterateprocess until finished

All Groups

Gather information forpost-drilling review

Engineering

Generate welltrajectory

Geology and Geophysics Geology and Geophysics

Finalize mud andcasing design

Engineering

Reports

Compile and updatereports weekly

Engineering

Finalize economicsand Authorization for

Expenditure (AFE)

Engineering

Preliminary Well Planning Detailed Well Design Drilling Operations Post-drilling

Load welltrajectory

> Traditional drilling workflow. A linear workflow requires more people and incurs higher cost because of inefficiency in the process. Iteration is time-consuming and costly, particularly at the stage when drilling target selection occurs. The lack of a shared digital database inhibits integration of dataand interpretations among team members. Integration, in this situation, depends on human interaction as well as duplication of data entry efforts inincompatible databases.

Retrieve latestversion

Finalize economicsand Authorization for

Expenditure (AFE)

Engineering

Preliminary Well Planning Detailed Well Design Drilling Operations Post-drilling

Project database

Update currentwell trajectory

Compile and updatereports

Engineering

Optimize welldesign

Engineering

Finalize mud andcasing design

Engineering

Drillingparameters

Drillinghistory

Hazards

3D reservoirmodel

Productionhistory

Structure

Stratigraphy

Prospectivetargets

Productionhistory

Reservoirproperty

distributions

Generate welltrajectory

Geology and Geophysics Geology and Geophysics

> Ideal drilling workflow. With team members using the same database and model of the earth, the drilling process becomes less linear. At each point in theprocess, validation occurs earlier, saving time and money. Inferior solutions are weeded out early in the process. The use of real-time data allows optimiza-tion of operations during drilling. After completion of drilling operations, results are readily available in the database to improve subsequent operations.

Winter 1998

Many exploration and production companieshave carefully examined their unique drillingworkflow to maximize the productivity of eachmultidisciplinary team and the value of eachasset. Schlumberger has worked with a numberof operators to identify the process best suited tothat company and the changes necessary toachieve it. Several common priorities emergedfrom these studies:• The ability to move targets and surveys easily

between G&G and drilling software to finalizethe drilling target early

• Standardized survey, well naming and coordi-nate systems

• Three-dimensional workspace and multi-useraccess with conferencing flexibility so that allteam members, be they at the wellsite, in theoperator’s office or in a service company office,can access data and the latest interpretations

• A link between G&G models and well-planningapplications that simplifies and speeds changesto drilling plans in real time, optimizing the wellpath and reducing the need to sidetrack

• The use of real-time data in application format,so that data entered in one application areautomatically available in all other applications

• An automated process for capturing actualversus planned results in operational andfinancial parameters

• Access to databases using query tools to pro-mote effective use of data and formal compila-tion and archiving

• The ability to move data easily between multi-user projects and stand-alone projects.

Technical HurdlesIntegrated software to streamline the drillingworkflow is a key to improving the process.Among the technical hurdles that must beaddressed, perhaps most pressing is the need fordigital data and a database architecture that pro-motes sharing of data and interpretations for theduration of a project. The amount and variety ofdata used to plan and drill wells are mind-bog-gling: seismic data, well logs, mud logs, coresamples and their descriptions, drilling fluidreports, directional surveys, drilling histories andproduction histories are but a few examples.

A clear understanding of both the existingand ideal workflows is essential, requiring a timecommitment up front to assess possible scenar-ios and solutions, such as what software to use,and the roles and responsibilities of each teammember. Willingness by team members to adaptand improve can ease the transition from the tra-ditional method to an improved process usingnew software. Many professionals are reluctantto abandon products with which they are familiar,even in favor of those that are better integrated.This is related to another cultural obstacle, a fearof many professionals—being replaced by com-puters. The reality is that as reserves becomemore scarce and difficult to exploit and wellsbecome more complex (multilateral andextended-reach wells, for example), multiplehypotheses or scenarios must be evaluated.Asset managers need to get more from existingresources. One solution is to provide better soft-ware tools that increase the efficiency of eachperson involved.

Integrated Drilling SoftwareAll software programs, even those performingcommon engineering calculations, must be vali-dated: the underlying algorithms must reflectappropriate, correct approaches to a given task.A management system in which the workflow,software and underlying policies and proce-dures are sound ensures both technical integrityand appropriate management of informationused in the system.

Several companies have developed individualsoftware tools to perform specific tasks in thedrilling workflow. Schlumberger also developed anumber of applications to assist with well plan-ning and design, cementing and other tasks. Asintegrated project management became a keyconcern, the need to use all the applications andavailable data together led GeoQuest to inte-grate its applications, which are collectivelycalled the Drilling Office system (next page).

More than merely performing specific tasksand integrating them seamlessly, the DrillingOffice system had to meet the Schlumbergerstandard of technical integrity, meaning that ithad to meet technical standards of performance,reliability and robustness for a given project: theworkflow, the applications used in the workflow,and the underlying methods and calculationsreflect appropriate procedures and technology.Each application uses validated algorithms foreach task, and within each task a selected pro-cess or flow reflects appropriate technical proce-dures for performing that task.

The Drilling Office suite currently includes:the PowerPlan modules for well trajectory plan-ning and design, torque and drag, anticollisionanalysis, bottomhole assembly (BHA) design andhydraulics analysis; the CemCADE tool forcement design and evaluation; the QLA well loganalysis software; the MudTRAK application fordrilling fluids management; the SideKick gas kickand underbalanced drilling simulator; the TDASTubular Design and Analysis System casingdesign system; and the WEST WellboreSimulated Temperatures program. Like allGeoQuest products, the Drilling Office system isYear 2000-ready. Validated by both Schlumbergerand the industry, these applications reflect bestpractices. The commercial software has beenused extensively within Schlumberger. For exam-ple, Dowell engineers have used the CemCADEprogram for over ten years to design cement jobsand Anadrill engineers have planned hundreds ofdirectional wells using PowerPlan modules.

6 Oilfield Review

Asset managers need to get more fromexisting resources. One solution is to

provide better software tools that increasethe efficiency of each person involved.

New applications in development include theWellTRAK system for well tracking and report-ing, a unique drilling data management system.The WellTRAK program is used at the wellsite tocapture drilling data and knowledge. In addition,it allows actual drilling activities to be trackedagainst the original plan so that the project teamcan readily identify suboptimal conditions andunplanned events and their costs. A linkbetween the WellTRAK program and the Findercorporate database will provide data manage-ment tools for well construction data as well asG&G information. Enhancements are under wayto allow engineering calculations to be updatedand calibrated using operations data whiledrilling. Reporting features that ensure compli-ance with quality control procedures are alsobeing developed for the software.

These modules can be used as relatively inex-pensive stand-alone applications or as part of afully integrated system that is designed to allowthird-party applications to be linked. The soft-ware runs on a personal computer (PC) using

Windows NT 4.0 or Windows 98 or 95 (with aminimum of 64 MB of RAM) and a recommendedprocessing speed of 166 MHz or greater.

In any software package, user friendliness iskey to acceptance and training. This is particu-larly true for integrated drilling software becauseworkflow analysis has shown that drilling engi-neers often use the software intermittently andhave little time to learn new packages. DrillingOffice applications follow the standard Windows“look and feel” to shorten the learning period andaccommodate cross-disciplinary use. End userswho have worked with only one module can learnthe entire system quickly. The modules will even-tually have a more common look and feel, whichvisually reinforces the movement of data and cal-culations from one application to another.

The Drilling Office suite is based on theGeoFrame heterogeneous computing environ-ment that uses the Standard Data Model devel-oped by the Petrotechnical Open SoftwareCorporation (POSC). POSC is a nonprofit organiza-tion supported by Schlumberger and other indus-try sponsors. The Standard Data Model was

initially designed for G&G data, so Schlumbergerhad to add the drilling view of data to the model.The applications in the various domains aredesigned to allow end users to access relevantdata without being overwhelmed by data they donot need—drillers do not see most G&G dataunless they seek them.

Future database functionality will includeimproved access privileges, whereby only theowners of a particular interpretation, the projectgeologists, geophysicists and engineers, canchange the interpretation, but the interpreta-tions appear to others as “read only” versions.For example, geophysical interpretations by theproject geophysicist or formation tops edited byonly the geologist can be viewed by well plan-ners. Versions of interpretations are retained inthe database, so if personnel changes occur dur-ing a project, the evolution of a particular inter-pretation can be established and reproduced,which prevents unnecessary, expensive duplica-tion of interpretive effort.

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Wellsite database Query tools

Wellbore stability monitoringCasing design

Trajectory planning

Mud and cementing designsThird-party applications

Project database

Master database

Well proposal and drilling policies Basis of design document Programs Operations tracking End of well reports

Planning and Design Execution Evaluation

Knowledge Management and Decision Support Tools

Validate and quality control

Print reports

Capture dataDrilling Office applications

Integrated data and reports

Reports and real-time data

Wellsitedata entry

> How the Drilling Office system works. A master database and integrated software tools are the foundation for Drilling Office integrated drilling software.Links to the wellsite allow real-time data transfer to optimize operations and continuous archiving for future reference. Such a system improves all phases of the drilling workflow from design and planning to execution and evaluation.

7Winter 1998

Well Logs

Petrophysical Modeling

Drilling Data

Seismic Modeling

Geological Modeling

Classification System

Reservoir Simulations

3D and 4D Seismic Data

Shared Earth Model

> Shared earth model. A central project database houses the numerical representation of the subsurface, the shared earth model, which is developed fromgeological, geophysical, petrophysical and drilling data. The shared earth model is used in the drilling workflow to improve drilling planning and operations.The database can be expanded, and the model enhanced, by adding real-time drilling data.

8 Oilfield Review

Changes in the geological interpretationaffect the well design, so a link has been devel-oped in the Drilling Office system between welldesign steps and the shared earth model. Theshared earth model is a concise numerical repre-sentation of the subsurface based on geological,geophysical and petrophysical data and modelsor simulations generated from them (previouspage).2 Such models, however, are inherentlyuncertain because of limited subsurface data,measurement errors and, in some cases, incor-rect models. Integrated software, the appropriatedatabase and a shared earth model allow real-time flow of data and interpretations to improvedecision-making during planning and operations.

The shared earth model affects many areas ofwell planning, including selection of surfacelocation, trajectory design, pore pressure predic-tion and wellbore stability, to name a few. Theuse of shared earth models for well planning hasalready had a positive impact in a number of fielddevelopment projects by reducing drilling costsdue to wellbore instability and stuck pipe. Thepending release of GeoFrame version 3.6 will, forthe first time, give drilling professionals using theDrilling Office suite on a PC direct access to theshared earth model developed by geoscientistson UNIX workstations to improve the drillingplanning and operations workflow.

Implementing Integrated Drilling SoftwareAs is true of any fundamental change in howsomething is done, integrated drilling software isnot a panacea. This new software consists of aset of tools, but does not automatically dictate aparticular workflow. Therefore, to realize themaximum benefit from the Drilling Office system,companies that adopt the system must evaluatetheir procedures critically and carefully. A givenworkflow can be modified to suit individualrequirements because the software is modularand flexible. In addition, if the entire suite ofapplications is not needed, a particular modulecan be used, such as a single application on astand-alone computer at the wellsite. The soft-ware facilitates the iterative nature of teamworkto achieve the best planning and real-time opti-mization of operations. Iterative and collabora-tive project planning and execution are enhancedby making individual applications compatible, asthe following generic case study illustrates.3

At the start of the drilling workflow, geosci-entists typically identify drilling targets on thebasis of attractive potential pay rather than thefeasibility of actually drilling to the target, whichis the primary concern of the planning engineer(above left). With properly integrated applica-tions, geological and geophysical data and inter-pretations in a project database are accessedwith software that generates a preliminary welltrajectory to select a drillable target. In the past,selecting the optimal drillable target from a num-ber of choices was a time-consuming process.With integrated software and a shared database,iterations between engineers and geoscientistsare reduced in number and duration whileachieving superior results (above right).

Target 1

Target 2

> Drilling target selection. Visualization software is used to overlay wellpaths on three-dimensional geological or geophysical interpretations. In this example from the West Cameron area of the Gulf of Mexico, the trajectory intersects two attractive targets in the surface interpreted from seismic data.

Target 1Target 2

>Well design visualization. Visualization software is used with the DrillingOffice PowerPlan tool to overlay a well design on a geological or geophysi-cal interpretation. In this example from the West Cameron area of the Gulf ofMexico, the trajectory selected by geoscientists (blue) has been modified bythe planning engineer to create a drillable trajectory (yellow) to both targets.

2. Beamer A, Bryant I, Denver L, Saeedi J, Verma V, MeadP, Morgan C, Rossi D and Sharma S: “From Pore toPipeline, Field-Scale Solutions,” Oilfield Review 10, no. 2(Summer 1998): 2-19.

3. McCann DP, Ritchie GM and Ward VL: “The IntegratedSolution: New System Improves Efficiency of DrillingPlanning and Monitoring,” paper IADC/SPE 39332, pre-sented at the IADC/SPE Drilling Conference, Dallas,Texas, USA, March 3-6, 1998.

9Winter 1998

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Once a target has been selected, the optimalwell design is created. The well design applica-tion in the PowerPlan module uses input designconstraints to rapidly create both plan view andvertical section plots. The design includes anno-tations of formation tops, casing seats andother critical points (left).4 Collision avoidance isachieved through the use of the Close Approachmodule and survey data from offset wells foranticollision analysis (below left). These appli-cations, along with the ones that follow, areused to create drilling proposals quickly. If thearea of the well target can be enlarged withoutcompromising well objectives, further cost sav-ings might ensue.

Information about offset wells is accessiblein the database and used to improve drilling per-formance in successive wells. BHA selection isoptimized during initial planning or during drillingby using the BHA Editor and DrillSAFE DrillstringForces Analysis modules in the PowerPlan appli-cation (next page, top). In complex wells, such asextended-reach drilling situations, BHA perfor-mance is especially important to the success ofthe operation. The DrillSAFE module is routinelyused for both torque-and-drag analysis and BHAtendency, including computing build and turnrates according to the hardness and other char-acteristics of formations drilled. Output from theDrillSAFE module is graphical and numerical andcapitalizes on both historical and real-time data.

With the PowerPlan Hydraulics application,drilling experience can be used to improve holecleaning and circulating hydraulics (next page,bottom). Circulating pressure losses and equiva-lent circulating densities are calculated, whichallows bit parameters, motor performance andhole cleaning to be optimized using the module’svalidated algorithms (see “Using DownholeAnnular Pressure Measurements to ImproveDrilling Performance,” page 40).5

> Anticollision traveling cylinder plot. A traveling cylinder map generated using the PowerPlan anticollision tool is valuable for both planning and drilling wells in densely drilled areas, such asfrom an offshore platform. The planned or actual subject survey is always at the center of the plotand the offset wellbores (red lines) show the distance and direction from the subject well. Real-timedirectional survey measurements while drilling are used to update the map and reduce the risk ofcollision with existing wells.

Plan view

Verticalsection view

< Directional well design. Drilling tools providedetailed trajectory information. Graphical outputincludes plan and vertical section views of thewell trajectory. Drilling Office applications have a look that is similar to common spreadsheet applications, making them user friendly.

4. Chapman CD: “The PowerPlan System Integrated DrillingPlanning: The Key to Optimization,” Petroleum EngineerInternational 71 (September 1998): 87-95.

5. Chapman, reference 4.

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>

> Bottomhole assemblies. The BHA Editor can be used for well planning. During drilling operations, real-time data allowdrillers to optimize BHA configuration and performance. The up-to-date information and new software capabilities are especially useful in complicated drilling situations, such as extended-reach drilling. In this view of the BHA Editor screen, the driller displays a schematic diagram of the BHA in use (center) and its performance specifications (right). In the left part of the view, the driller navigates to detailed views of the drillstring.

>Wellbore hydraulics. The Drilling Office system contains a wellbore hydraulics module that can help improvehydraulics planning and operations. The wellbore hydraulics tool allows calculation of pressure loss (left), equivalentcirculating density, and motor performance (right) and hole cleaning analysis.

11Winter 1998

When well construction begins, real-timedata are available to all team members so thatoperations are optimized and hazards are antici-pated and avoided. The well design can be mod-ified if predrill predictions are not correct, such aswhen a formation top associated with a casingpoint is higher or lower than predicted.

Planning might involve a spectrum of possi-bilities, whereas operations occur within a lim-ited range of conditions. Individual modules ofintegrated drilling software make use of differentalgorithms depending on the operational rangesor assumptions. Real-time changes during opera-tions are incorporated readily into plans toimprove predictions and anticipate potentialproblems. For example, as a mud system changeswhile drilling, hydraulics calculations incorporateits variations. Real-time torque-and-drag dataallow drillers to make more accurate predictionsahead of the bit. The well trajectory can be mod-ified and performance of the BHA optimized byincorporating real-time data into modeling appli-cations for calibration purposes.

In addition to core drilling applications,there is a need for integrated petrophysicalanalysis, casing and cementing design and tem-perature simulation. Interactive well log analy-sis is performed using the QLA Well LogAnalysis module. The TDAS application includesan expert system that guides engineers toquickly design the lowest cost casing or tubingstring from available inventory using an overallcorporate design philosophy. The TDAS applica-tion also ensures that casing designs meetAmerican Petroleum Institute (API) standardsand International Organization for Standards(ISO) criteria. The CemCADE cementing soft-ware helps engineers plan successful cement-ing jobs from large-diameter surface casing tothe deepest liner. Efficient scenario planningreduces waiting-on-cement time, avoids reme-dial cementing and ensures well safety.

For planning and drilling high-pressure, high-temperature (HPHT) wells, the Drilling Office sys-tem includes advanced simulators for gas kickand temperature modeling, critical aspects forsuccess in these wells.6 The gas-kick simulatorwas the result of extensive research bySchlumberger and BP International Ltd. The pro-ject was initiated by the UK Health and SafetyExecutive (HSE) Offshore Safety Division follow-ing a number of well-control incidents on HPHTwells. Anadrill commercialized the resulting soft-ware as the SideKick program. Additional devel-opment was funded by the European UnionThermie program. The SideKick simulator modelsinfluxes, such as gas kicks, and can evaluate risk,design casing programs and plan procedures forcontrolling HPHT wells.7 The WEST programimproves temperature predictions by engineersduring drilling and cementing operations.

Complex wells constitute perhaps 20 to 30%of total wells drilled, and the benefits of teamwork and data sharing in these cases areobvious. Simpler wells can also be improved,

however. A major benefit of integrated softwareand streamlined workflows can be achievedthrough an assembly-line approach to the simplerwells: the planning cycle is shortened, workbecomes consistent and repeatable, productivityand cost savings increase dramatically. The workbecomes less of an art and more of a streamlinedoperation, with greater efficiency, simplicity andreliability. This shortens the drilling time-depthcurve and ultimately reduces cost per barrel. Bymastering simple, routine operations, engineerscan then concentrate on improving processes,procedures and ways of operating (below).

For example, an engineer developing amature oil field might realize that a single multi-lateral well is a cost-effective replacement fornumerous vertical holes, or that it is possible toreduce the number of casing strings (see “KeyIssues in Multilateral Technology,” page 14). Theability to study scenarios and improve on tradi-tional approaches leads to reduced cost and riskin both simple and complicated situations.

EVALUATE

EXECUTE

DESIGN

Conceptualdesign

Detaileddesign andplanning

Rig sitecontinuousimprovement

> DESIGN-EXECUTE-EVALUATE. Project teams develop a learning culture by constantlyimproving planning and operations. Integrated drilling software and a shared database support such continuous improvement. By working together and understanding each other’sroles better, geoscientists and engineers increase efficiency and reduce cost and risk.

6. For more on use of the SideKick simulator in HPHT wells:Adamson K, Birch G, Gao E, Hand S, Macdonald C, MackD and Quadri A: “High-Pressure, High-Temperature WellConstruction,” Oilfield Review 10, no. 2 (Summer 1998):36-49; and Rezmer-Cooper IM, James JP, Fitzgerald P,Johnson AB, Davies DH, Frigaard IA, Cooper S, Luo Y andBern P: “Complex Well Control Events Accurately Repre-sented by an Advanced Gas Kick Simulator,” paper SPE36829, presented at the SPE European PetroleumConference, Milan, Italy, October 22-24, 1996.

7. MacAndrew R, Parry N, Prieur J-M, Wiggelman J,Diggins E, Guicheney P, Cameron D and Stewart A:“Drilling and Testing Hot, High-Pressure Wells,” Oilfield Review 5, no. 2/3 (April/July 1993): 15-32.

12 Oilfield Review

Companies that incorporate the Drilling Officesystem in their technical computing strategieswill benefit from better data management, dataintegration and evolving computing standards.Integrated drilling software will improve planningand execution of drilling operations by reducingerror and redundancy in the workflow. The com-panies can also expect to manage, use, integrateand understand their data better.

A major oil company has tested the DrillingOffice tool suite and provided feedback toGeoQuest developers. The company is adoptingthe system as part of their internal computing ini-tiative. Several E&P companies seek to buy ratherthan develop their own applications for general,mainstream needs and to develop proprietarysoftware only for rare cases of unique needs. Forsuch companies, the Drilling Office system willmeet the need for both general drilling planningneeds and specialized real-time calculations.

Looking AheadIntegrated software for drilling planning andoperations is a response to the need for productsthat support integrated, multidisciplinary work-flows and today’s more exacting requirements fordesign and accurate placement of wells. Ideally,such software should follow the drilling processnaturally, have a single database for each projectand house applications that represent the bestpractices of the industry. Schlumberger will con-tinue to enhance the capabilities of the DrillingOffice system. In contrast to stand-alone applica-tions that focus on individual tasks, the mostpowerful drilling software will integrate andunify tasks into smooth processes. As assetteams focus more on the overall process at hand,the value of corporate assets, that is, reserves inoil and gas fields, will be maximized (above).

As the use of integrated drilling softwareincreases, members of project teams will betterunderstand each other’s disciplines and rolesthrough the new perspective of a shareddatabase. By implementing the use of integratedsoftware whose technical integrity has beenclearly demonstrated at each stage of the work-flow, companies can document their compliancewith regulatory requirements, such as zonal iso-lation of water from hydrocarbons or shallow gaszones, more readily.

Just as integrated drilling software providesa seamless link back to geological and geophysi-cal exploration applications, future functionalitywill include a similar link forward to the produc-tion phase that follows. A single database and anintegrated suite of applications will simplify theexploration and production workflow from projectconception to maturity. —GMG

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> Value of technology. The value of corporate assets increases as software is used to integrate tasks and improve thefocus on the total process rather than discrete tasks. Value, the y-axis, is both the perceived value to team membersas well as the monetary value to the corporation. The value attributed to each item listed along the x-axis depends onwhether one is task-oriented (bottom curve), process-oriented (middle curve) or taking the viewpoint of a corporation(top curve). Task-oriented people are most concerned with content and usability. Process-oriented professionals seekintegration and standards. Corporate leaders recognize that data and process integration maximizes asset value.

13Winter 1998