Summary.
Interactive computer graphics systems have been accepted in manyexploration and production operations to solve substantial geoscience problemsmore efficiently and accurately. Examples from several sources will be used toillustrate a few of the interactive solutions available. To illustrate thesenew developments, this paper introduces the basic components of the interactiveenvironment, reviews the hardware and software system used to produce theexamples, describes the interactive interpretational process, and presents theexamples with a summary of the geologic problems represented.
Interactive Environment
Exploration workstations provide a window into data. This window becomes anextension of the explorationist's mind, allowing rapid testing of differentgeologic concepts. Workstations generally have variances, however, in computingpower, available applications, cost, and user expertise. These differences havehindered sharing of information between different users and have createdbarriers between disciplines. The new interactive environment is dissolvingthese differences. New microcomputers, with the power of yesterday's miniormainframe computers, are providing ever-increasing computing power to solvecomplex applications. Improved connectivity between workstations and the entirerange of host computers, from minicomputers to vector processors, is allowingmore information sharing. Although applications are in specific disciplines, most computer-aided applications needed in exploration and production areavailable for integration in a workstation environment. The interface betweenthe computer and the user has been demonstrated, but is not widely available. Systems follow several growth paths as they evolve toward an integratedexploration system. Complete systems will do appropriate seismic processing, two- and three-dimensional (2D and 3D) seismic interpretation, seismicmodeling, mapping, image processing, well log analysis, geologic work, databasemanagement, reservoir modeling, economic analysis, etc. Evolution toward anintegrated exploration system is a function of good software tools, feasiblehardware growth paths, and the right general development environment.
Hardware and Software System
Workstations consist of a few key components.
These include the computer(stand-alone or host-based), graphics monitors (high or low resolution), digital storage devices (local or shared), input/ output methods, applicationsoftware, and a planned or an agglomerated user interface. The key question iswhether the system being evaluated helps solve a problem in a manner betterthan traditional methods. This is a function of the application software. Theinterpretation system used was a stand-alone Landmark III. The hardware ispackaged like a desk. The CPU was the industry standard Intel 80286microprocessor with an 80287 coprocessor, since upgraded to the Intel 80386. Both processors are in a 21-slot Multibus TM with 4 megabytes (MB) of mainmemory. Main memory is shared by a 16-megaflop array processor. The keyperipherals are a 1,600/6,250-bytes/in. tape drive, 440 MB (formatted)winchester disks, the graphic processor, and associated 1,280 X 1,024 pixelmonitors. The second monitor and windows allow simultaneous work with seismicand map data. Seismic data, attribute data, well log location information andlogs, horizon files, picture files, and animation files are stored on largewinchester drive(s). Sun's system has been field upgraded from 880 to 1,760 MBof formatted disk capacity and could be further expanded to more than 7,000 MB. However, new capabilities to share disk capacity between systems over theEthernet local area network, and optical disks with 1,000-MB removableplatters, are removing the need for configurations with more than 2 GB offixed-disk drives. The open architecture provides an ability to integrate newhardware, which helps keep the system current. The software used in this studywas written specifically for 2D or 3D seismic interpretation. The userinterface was designed for those who often do not have a computer sciencebackground, making the applications easy to use. Most system interaction isthrough a digitizing puck and hierarchical menus, comparable to working withcolored pencils on paper seismic sections. The menu structure is designed tosupport interpreters' everyday tasks. Traditional interpretation techniques aresignificantly improved because the software keeps track of the data, rapidlyretrieving them in display formats specified by the user to enhance geologicinformation. One of the key factors is the fast, predictable response time, which allows users to try different interpretation options quickly. Forexample, as horizons are digitized, they are automatically posted to a horizonfile and can be recalled instantly for evaluation in map view. Map evaluationallows rapid study of the geological accuracy of different interpretations. Thesoftware structure and development environment encourage integration anddevelopment of new applications. The software is 95% ANSII-77 FORTRAN, withstandard Unix 5.3 software development tools like editors, debuggers, linkers, compilers, and library managers. The libraries developed for 2D and 3Dinterpretation can be used to develop new applications or to access differentdata types, such as horizon files. SURFASLM is an example of an availablethird-party software package that can grid irregular or incomplete horizons anddisplay the results in a perspective or map view. In addition, the differentapplications, libraries, and third-party packages are supported with bothregularly scheduled updates and quick fixes if major bugs are found.
Interactive interpretation Procedures
Interactive seismic interpretation procedures are similar to traditionalmethods of working with paper sections. A major difference is the ability totest, change, and retest different geologic concepts. A few of the interactivecapabilities that affect creation of an accurate geologic model include havinga computer data base for easy section retrieval, display parameters to enhancegeologic information in the displays, horizon-picking options and automaticposting, horizon computations, and map displays.
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