from initial exploration assessment through appraisal programsfield development planning and secondary recovery projects.
” Performed on a consulting basis for clients (typically asset team end-users), reservoir characterisation services…
These services have turned into a rapidly growing activityoperating either as part of a dedicated or integrated service companiesor as business units within oil and gas companies.
These services are by definition a deadline-constrained activitybut beyond the deadline are periods of little or no work as the results are being used to steer a drilling programor facilities are being built and put into production. At the point in time when a final delivery has been made to the clientthe service provider needs to collect all relevant data used or produced in the course of the projectto ensure safe keeping and potential access at a future date.
The client can indeed decide at any time in the future to request additional work in continuation of the last deliverables. It is therefore important for the service provider to be able to pick up the workflow where it was last suspendedand proceed as smoothly as possible to produce the newly-required results.
Very large integrated software and database suites are normally hosting a large percentage of RC datawith two products foremost in the industry: GeoQuest’s GeoFrame.suiteand Landmark’s OpenWorks?. Both use a complex data model managed by the Oracle. RDBMSand address many data processing and interpretation capabilities through the use of tens of applications. Howevermany other applications are used in RC servicesoriginating from independent software providersor developed by the service provider as a specific value proposition. These applications will run either on Unix or PC platforms. Reports are written using PC applicationsand graphic packages will often be put to use to produce assemblies of visuals for project presentation purposes.
Data for a project will therefore comprise a diversity of data typesstorage structures and groups of filesstored on UnixPC or network storage filers. The notion of project data must therefore encompass all these different sources and structures of dataso that the accrued knowledge relative to the project can be captured in its entirety.
Server A Server B Server C NAS Project data is frequently managed by different applicationsand can be spread over many file systems and serverspopulating databases and/or directories with many different data types and file formats.
The first task of a Data Management Solution (DMS) will be to allow for a comprehensive encapsulation of all data related to a service project into a single bundlewith appropriate labelling for future retrieval. This process must therefore be application-awareie understand how each application or family of applications stores datahow to trace and store the lists of physical files and their locationsas well as extract from the RDBMS all the descriptive and relational information necessary to snapshot the projectand enable future restoration.
Constructing an archive of a project will then consist in identifyingfor each application usedthe lists of data files that need to be associated to the project. This list will constitute the contents of the archive. In additionsome descriptive information is required to label the bundle of datasome of it factual (user namesgeographical locationdatesvolumes of dataetc)some of it free-formattedfor comments and qualifiers relative to the archive.
It is perfectly conceivable to do all these tasks manuallyor by the use of scripts. But when the long-term goals of the business are put in the equationand one considers the scarcity of time and skills to manage effectively such a taskthis is not realistic. Automation comes to the fore as the most efficient solution to satisfy project archiving needs. Three levels of automation are necessary to fulfil the brief: l l l Whether as a contracted company working for a clientor as a department or business unit within a larger companythe activity related to reservoir characterisation is often on the critical path of a large asset development project. Delays in delivery affect massive investments and the timely deployment of considerable resources. This can go from weather windows to the time-constrained availability of a scarce commodity such as deep-water drilling equipment.
Terabytes of disks are being backed up dailyand make it possible to re-instate a defective disk drive should it malfunction. But how can one cover for a major loss of a facility (and its computer resources) in the event of a firea flooding or an electrical incident?
Setting up a temporary location to continue work as best possible on the most critical projects demands a specific approach. It will not be possible to procure at one or two days notice the equipment equivalent to thatwhich has been lost. Nor is it necessaryas all work and all data was probably not critical. What counts is to get back to work on the few (10 per cent to 30 per cent?) projects that can suffer no delayand make sure that the geoscientists can resume work within 24 to 48 hours.
Regular snapshot archiving of these critical projectswith a copy going to a secure off-site locationwill provide for the availability of the data. Further thought must be given to having in reserve some bare-bone computer systems capable of hosting the most necessary applications for the interim periodwith valid licenses at all times. Finallya configuration (tape drive plus server) capable of restoring the archive media to these systems will be needed.
Rehearsal is key to getting these components rightand ensuring thatshould the unthinkable happenall actors know what to doand all equipment is ready to rollto ensure successful operation during the emergency period.
Disaster Recovery is now a well-identified field of activityand service companies can provide turn-key solutions including stand-by staff and equipmentconsulting to establish the policies and procedures for disaster recoverydry runs and much more. Costs are reasonable in comparison to the risk of missing deadlines and forfeiting critical project completion. Like insurancethinking of Disaster Recovery before a disaster hits is the best way to minimise the impact. It is also a strong statement towards clients regarding responsible risk management.
A reservoir characterisation project can include a large amount of datawith the main volumes of data comprising simulation and seismic informationbut also graphic metafilesimagesetc. While this project is activeall data must be accessible with minimal latencyto facilitate rapid turn-around.
Experience shows thatin most instancesa project is never entirely finished. Clients can come back after a few weeks to challenge some assertionsor to request more insight into areas of interest. Assuming that action was taken following the results of a projectwhen new wells have been drilled or additional production information is acquiredthis data should be integrated into the model and the impact on reserves or development planning should be quantified.
4D seismica cyclical activity to assess changes in reservoir depletion over timeintroduces additional incentives to pick up old projects to perform further work. The probability of a project returning to live status is therefore relatively high. The unknowns are whenand what for? Leaving all projects on magnetic disk mediano matter how cheap such media can beand leaving their instances in the relational databasesburdens the overall service activity. It also means that the cost of disk storage must be factored into the project budgetas the resources will never be released for other uses.
The alternative is to ‘park’ the standby projects on a near-line storage systemwith an index of all these projectstheir contents and other information of interest. Once the integrity of the “parked” data has been verifiedthe project can be erased from diskallowing other projects to use the disk resources. A ‘parked’ project should be re-instated with relative easetypically on an application basis (eg re-instate the SeisWorksGeolog and Eclipse files only).
Tape cartridge systems The integration of a tape library system into an existing IT environment is frequently perceived as a delicate and difficult taskthe more so when hardware support skills are scarce. It is important to pay attention to the I/O layer of the archiving solution to ensure that it interacts transparently with the libraryadapts to the throughputmanages exceptional situations in a sensible mannerand in general takes care of the intricacies of the hardware with little or no intervention from company staff.
Solutions exist nowadays involving modern tape management hardware and transparent I/O layers that in effect isolate the user and administration communities from any involvement in the daily operation of a tape librarybeyond feeding and removing tapes as instructed by the software. These systems are cost effectivehighly reliable and require little or no resident skills to provide durable and robust services. Jim Ashford is with Enigma Data SolutionsHaywards HeathWest SussexUK. www.enigmadata.com
Automate data collection: for each application or databasedefine the rules and mechanisms that make it possible to locate and list exhaustively all the files of a specific projectfor inclusion in the archive.
Automate metadata acquisition: use interactive interrogation windows to inputstore and retrieve the information describing the project. This data is known as metadataand is ideally managed by a relational database.
Automate the archiving job: the process of allocating tape media for the archiverunning the archive joband verifying the outcome to ensure that all the data has been securely recorded on tape.
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