Exploiting Prestack Seismic from Data Store to Desktop Solutions to maximize your assets. Landmark Software & Services
Exploiting Prestack Seismic from Data Store to Desktop Author: Ciaran McCarry, Principal Consultant, Information Management Every year, E&P companies worldwide make substantial investments in acquiring, processing, and interpreting seismic data. Until recently, interpreters and asset teams worked almost exclusively with stacked representations of these data. Typically, companies archived the original field and other prestack data in tape stores or offsite warehouses. However, there is a growing realization within the industry that prestack seismic represents an underexploited corporate asset from which far more value can be extracted. Greater access to, and use of, prestack data can improve understanding of complex reservoirs in conventional and unconventional plays, dramatically reduce uncertainties associated with structural and stratigraphic interpretation, and ultimately increase production and reserves replacement. In this paper, we review the challenges and benefits of reprocessing prestack seismic data, and engaging interpreters more collaboratively in the process. We briefly describe three technologies necessary for operators to begin incorporating prestack seismic in mainstream interpretation workflows, as well as two ways of implementing prestack solutions from data store to desktop. The Promises and Perils of Reprocessing Seismic Data To improve the accuracy of subsurface analysis and interpretation, operating companies can either acquire new seismic data or reprocess existing data. Managers often find reprocessing older vintage data an attractive option since it is less expensive and time-consuming than acquiring and processing new data. However, not all data sets are suitable for reprocessing. The effects of a disastrous seismic recording campaign may be irreversible, leaving a reshoot as the only option. It is necessary first to assess how much the acquisition may have affected data quality. Original field survey and processing reports can be useful in highlighting acquisition problems. If it turns out that the original data was recorded with acceptable parameters, reprocessing using modern, state-of-the-art techniques can often yield significant improvements in reflection detail, image quality, and frequency content especially when focused on specific issues identified during interpretation and modelling. For example, applying advanced imaging techniques to legacy prestack seismic can deliver higher-resolution images of complex geologic environments such as deepwater salt bodies, overthrust regimes, and lateral faults. Prestack seismic can also assist in determining fracture patterns in low-permeability formations such as shale or tight carbonates and sands. To better understand reservoir behaviour over time, identify bypassed oil, and maximize recovery rates, operators increasingly rely on time-lapse (4D) surveys, which require consistent reprocessing of multiple vintages of prestack data. Despite its potential value, reprocessing is not a trivial exercise for most operators. First, it is necessary to make the business case and secure a budget. Once approved, it is customary to 1
outsource the project by conducting a competitive processing trial on a representative data subset among several seismic-processing companies. Appropriate seismic and navigation tapes must be located, selected, copied, and shipped to the winning contractor. The collection, transport, quality control, and conditioning of prestack seismic data and relevant metadata can take weeks. Time-consuming processing trials are often required to determine the optimum reprocessing workflow. Only then can bulk processing begin. Upon completion, original field tapes and reprocessed stack volumes are returned to the operator, who must load the new data into familiar interpretation systems. Typically, the level and quality of collaboration between the processing contractor and oil company geophysicists is quite low. Interpreters tend to have only intermittent remote access to processing results, or schedule onsite visits only at key decision points in the reprocessing sequence. For companies with in-house processing capabilities, collaboration may be somewhat better. However, processing and interpretation technologies are rarely well connected, and internal staff are still faced with the challenge of managing large prestack datasets and maintaining expensive IT infrastructures. The long, costly, and disjointed process of reprocessing prestack seismic data could be vastly improved, and additional value realized by building a real-time collaborative or interpretiveprocessing environment. Whether contractors or employees, when processing geophysicists can work together more seamlessly with interpreters, they can quickly select subsets of the prestack data to be reprocessed and make better joint decisions on processing sequences and parameterization. Reprocessing will always remain the domain of seismic data processors, especially the application of new algorithms early in the processing sequence and the correction of inadequacies in the original processing. Nevertheless, if processors and interpreting geoscientists can collaborate more effectively and clearly understand one another s challenges at every stage of reprocessing, they can deliver superior solutions faster. The Value of Providing Prestack Data to Interpreters In addition to enhancing reprocessing workflows, there are advantages in making prestack data increasingly accessible to the desktops of mainstream seismic interpreters. Correlation of prestack seismic amplitude variations with well log information can dramatically improve understanding of changes in fluid and lithology across a reservoir. As hydrocarbon environments become more challenging and complex, access to and analysis of prestack seismic data will play an increasing role in future interpretation workflows. Why, then, are so few oil companies today exploiting the full potential of prestack seismic data? Anyone who has worked in or supported digital infrastructures for E&P interpretation understands historically why prestack data has been confined to the processing domain. 2
One issue is that asset teams already have vast volumes of data to contend with well logs and curves, seismic surveys, spatial data, and metadata. Most of this information is managed in project databases or online file systems designed for quick delivery to interpretive workstations. Introducing additional, larger prestack data objects to this mix can appear daunting, not just to interpreters themselves, but also to IT staff and data managers. When it comes to seismic data, today s IT systems have evolved to manage post-stack data efficiently. The main barrier to increased use of prestack seismic in everyday interpretation projects is, in fact, the sheer size of these datasets. Modern 3D surveys of several hundred terabytes (TB) are already common, and new acquisition techniques such as single-sensor and high-density wide-azimuth recording are enlarging data volumes dramatically. IT departments struggle with the storage and network technologies necessary to efficiently manage such large data sets and make them accessible to interpreters. Improving Access to Prestack Seismic Given the enormous promise of prestack seismic data to exploration, development, and production workflows, how can oil and gas companies begin providing interpreters with greater access? There are three main E&P software technologies operators must consider when dealing with field and prestack seismic data: Online master data storage. The first building block of any prestack workflow is an online corporate or national data repository (NDR) capable of storing and enabling multiple teams to efficiently locate and retrieve both prestack seismic and other information. Seismic processing system. The second required technology is a comprehensive seismic data processing system capable of processing large volumes of land or marine 2D/3D/4D data. Prestack interpretation capabilities. The third building block is an interpretation system capable of interactive visualization, analysis, and control of prestack data types. To assemble these components into viable prestack workflows, oil companies can take one of two basic approaches: Option 1: Choose standalone data storage, processing, and interpretation tools from different vendors and link them as effectively as possible. Option 2: Deploy a comprehensive, commercially integrated solution covering the entire prestack workflow from data store to the interpreter s desktop. Option 1. Link Multi-Vendor Standalone Applications To date, most oil companies have viewed data storage, seismic processing, and interpretation as separate technical domains, best handled using standalone technologies. Selecting these systems based solely on price, performance, supportability, out-of-box functionality, or ease-of-use typically 3
creates a multi-vendor application environment. In addition, this environment may extend beyond oil company boundaries, if one or more components are outsourced to third-party providers. Since standalone technologies often depend on proprietary data formats optimized for a specific application, they can improve performance within a single domain. However, they do little to facilitate better collaboration across a crossfunctional workflow. They can, in fact, increase barriers between the disciplines. Propriety data formats require convoluted import/export routines, and cause inevitable data duplications at every stage of the prestack workflow. The resulting bottlenecks, delays, and inconsistencies often negate the productivity gains realized when a tool is used within just one discipline. This is especially problematic in prestack seismic workflows where reducing or completely avoiding data duplication is essential, due to the sheer size of the data volumes. Using commercial software development kits (SDKs) and application programming interfaces (APIs), IT and IM departments can connect multi-vendor standalone applications and databases to build a highly customized system tailored to their specific requirements. While this approach has certain advantages, it demands a considerable upfront investment of time and resources on the part of internal staff. Down the road, even more effort is required to maintain and upgrade customized environments to keep pace with increasingly rapid advances in both hardware and software. Few companies, small or large, have the requisite knowledge or skills in-house to integrate or manage such systems efficiently over the long term. In that case, they may consider the second major prestack option. Option 2. Deploy a Comprehensive Integrated Solution In choosing applications or third-party providers for the storage, processing, and interpretation of seismic data, energy companies should view the entire prestack workflow holistically from data store to desktop. Adopting a comprehensive, fully integrated solution can exploit prestack data more effectively, and improve collaboration at every step. With an integrated system, cycle times for reprocessing can be minimized. Processing and interpretation geophysicists can work together without the barriers and delays of standalone applications. As a result, they can solve geological challenges faster, producing more confident and accurate reservoir models. One potential downside to bringing a commercially integrated solution in-house is that all components may come from a single technology provider, which some operators may perceive as limiting their freedom of choice. However, the pitfalls of standalone tools and the collaborative benefits of integrated applications make this an attractive option to many others. What are the capabilities oil companies should look for in the three main components of an ideal prestack workflow solution? A. The Data Storage Component. The challenge of managing big data is driving advances in disk storage capacity across all industries. Costs have dropped to a point where it is now practical 4
to store numerous petabytes (PB) of prestack seismic data on disk in corporate or national data repositories. To meet the industry s current and future needs, master E&P data stores must be capable of bringing online bulk field and other prestack seismic data types in both SEG-D and SEG-Y formats, when they are needed. Observer s logs, processing reports with geometry, navigation files, and existing velocity models must also be accessible for rapid search and retrieval, whether they are maintained near-line or in offline archives. All data must conform to predefined data governance standards to ensure they meet the level of quality required for corporate reference or gold standard data. In the case of an external NDR to which multiple clients are granted access, strict entitlement regimes must be enforceable to ensure the right data is accessible to the right client. Software systems intended to manage online master data stores must enable rapid search, selection, and retrieval of quality-controlled prestack data. Since geoscientists often do not require all prestack data from a particular survey, the data management software must allow them to interactively choose and extract only relevant prestack seismic traces for delivery to processing and interpretations systems. The ability to easily subset data is a critical component of any integrated solution, since it reduces overhead and safeguards the performance of existing IT infrastructures. B. The Seismic Processing Component. Seismic processing software should be able to consume online data directly from disk, and condition and publish interpretation-ready post-stack and prestack data to the desktop. A comprehensive seismic data-processing system must combine ease-of-use with efficient interactive analysis tools, strong geophysical algorithms, and optimization for parallel processing. A range of advanced compression algorithms should be available to minimize the size of output data sets. Analysis and interpretation needs will dictate the specific compression strategy. Whether processing is handled in-house or outsourced, the optimum solution would be an industry-standard system with proven integration capabilities. To facilitate seamless exchange of seismic data, velocity data, and interpreted horizons, the processing system should be tightly integrated with both the master data store and the interpretation software. To minimize data duplication, the processing system must also catalogue key prestack metadata and associate that prestack data with interpretation projects, enabling interpretation technology to directly read processing-formatted data sets. C. The Interpretation Component. To prevent unnecessary delays, it is critical for integrated interpretation software to download selected prestack data from very large processing-formatted data sets at speeds comparable to familiar post-stack downloads. For mainstream interpreters to take full advantage of prestack seismic data, their desktop interpretation systems must handle prestack data in multiple map, section, and cube views. Interpreters must be able to easily visualize and manipulate prestack data in the context of their stacked seismic volumes. The technology should provide a set of tools for processing and analysis 5
of selected prestack seismic and well data in a highly interactive environment. D. The Implementation Component. One way oil companies can install and roll out an integrated prestack workflow solution is to do it themselves, if they have the appropriate expertise in-house. On the other hand, many operators may need to consider investing in expert third-party data management services, both for initial design and deployment of new technologies and for support of on-going operations. This effectively removes the burden of managing the data and maintaining technical applications from internal staff, freeing them up to spend more time on higher-value exploration and development activities. Options for deploying integrated prestack workflows include scalable managed services, either within the operating company (behind the firewall) or remotely hosted by a third-party service provider. Online hosted solutions like these will be of special interest to any oil and gas company that lacks sufficient in-house data management expertise or the requisite IT infrastructure. The Smart Way to Deliver Prestack Seismic from Data Store to Desktop Having considered three critical components and two basic ways of implementing prestack solutions, we recommend taking the integrated approach. We may be biased, but we have spent two decades building integrated systems that accelerate complex workflows and facilitate unprecedented collaboration across organizational silos. Today, Landmark offers both integrated technologies and expert professional services to assist clients in designing and delivering intelligent prestack seismic workflows from data store to desktop. The following are the components we recommend for a total solution. 1. Master Data Store. PetroBank Master Data Store software technology manages bulk prestack seismic data storage online, for rapid distribution to a network of clients. It is used widely throughout the industry in both corporate and national data repositories. PowerExplorer software is our Web-based GIS data management software. Its advanced capabilities enable Figure 1. PowerExplorer search, select preview, and download Figure 2. Velocity analysis using SeisSpace 6
data management professionals to browse and manage spatial and tabular E&P data, providing a complete picture of data availability in the PetroBank Master Data Store application. 2. Seismic Processing System. SeisSpace software is Landmark s next-generation comprehensive seismic processing system, optimised to handle large data volumes while allowing rapid visualization of pre- and post-stack seismic. It is used both by oil companies and seismic processing contractors. SeisSpace software shares a common prestack data model with Landmark s suite of analysis and interpretation applications. Not only does this reduce data duplication, but also provides mainstream geoscientists with direct access to prestack seismic in their own environment. Figure 3. Prestack gathers in the DecisionSpace 3. Interpretation Workspace. Landmark s Geosciences interpretations suite DecisionSpace software provides a unified multidomain workspace for asset teams to collaborate more efficiently and solve complex subsurface problems more accurately. Well Seismic Fusion software and the DecisionSpace Geosciences suite provide interpreters with a range of seismic interpretation and analysis tools for the integration or fusion of prestack seismic with well data. The interpretation Figure 4: Key activities supported by services environment was designed to handle prestack data as easily as post-stack data. In fact, interpreters can access prestack seismic with a single mouse click. 4. Professional Services. Of course, technology alone is never a complete solution. Needs assessment, design, testing, implementation, data migration, and support all require expertise in planning, deploying, and operating sophisticated technologies in collaborative environments. Landmark s experienced professional services organization can add substantial value through best practices in the management of bulk prestack seismic, as well as training and support. Our hosting solutions for data and/or applications, delivered by unique vspace hosting technology, represent one example of professional services we can provide to enable efficient prestack seismic workflows. Flexible options are available for managed services delivery either from the cloud or behind the firewall. 7
The Future of Integrated Prestack Processing and Interpretation The future for prestack seismic workflows looks bright. Giving interpreters the ability to interactively deconstruct a stacked seismic trace is a powerful tool to aid in understanding the geologic model it represents. Through careful analysis of prestack data, geophysicists can recover valuable information normally lost in the stacking process. The payoffs include more accurate and confident interpretations and improved decision making in complex offshore and onshore, conventional and unconventional plays. On-going performance improvements in compute power and storage capacity ensure that oil and gas companies can efficiently stream selected prestack data from national or corporate data repositories to the desktops of processors and interpreters. Coupled with the ability to condition data along the way, the emergence of common data formats for processing and interpretation data enhances opportunities for operators to leverage prestack seismic in a growing range of future exploration and production projects. About Landmark Services Landmark Services works with companies to improve business processes, optimize operations, deliver innovative solutions, and accelerate adoption of Landmark software. We are experts in E&P technology and learning and have methodologies designed to help companies like yours succeed. Our consultants work worldwide, spanning five practice areas: Intelligent Operations, Information Management, Cloud Services, Technology Adoption, and Education. Our goal is to help you transform your business and maximize assets by enabling the safe, fast, and accurate decisions needed to find and recover every last drop of hydrocarbons. For more information, contact your Landmark account representative or send an inquiry to Landmark@Halliburton.com. 8
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