GEOSCIENCES

Dev George
Houston

• GeoFrame 3.0 correlates VSP data with seismic and well data (key sands are delineated using voxels) [46,222 bytes].
• StratWorks provides ease in correlation between well logs and seismic ata. [38,860 bytes]
• Read's circle/spiral shoot. [40,811 bytes]

SEG Highlights

The technical program at this year's Society of Exploration Geophysicists annual meeting and exhibition in Dallas included numerous papers on recent advances in the geosciences, especially in areas of waveform analysis, seismic velocity and acoustic impedance, pore geometry characterization via nuclear magnetic resonance, 3D integrated basin simulation and visualization, and the various geophysical issues of 4D seismic reservoir monitoring. Outstanding exhibits included the following:

• The introduction of the Geoframe 3.0 reservoir characterization system by Schlumberger GeoQuest, which adds the power of IESX and Charisma seismic interpretation to the fully integrated geological, geophysical, and petrophysical system. The result of three years of development, the new 3.0 Geoframe will enable multidisciplinary asset team members to simultaneously view, edit, and interpret data and results through all phases of a project. This via the creation and maintenance of a single project database that expedites prospect interpretation and well planning. IESX and Charisma users are thus able to access complete geophysical and geological interpretations capabilities as well as petrophysical analysis.
• Western Geophysical's display of the results of its 4D/4C acquisition in the Gulf of Mexico for Texaco, said to be a first in the region. The first installment of this time-lapse (4D), three-component geophone and hydrophone survey was on Block 354 of the Eugene Island area. Western employed its ocean-bottom cable (OBC) technology and specially designed multicomponent recording equipment from Input/Output in conducting the shoot, which is planned to be repeated in six months and several other times in the future so that any changes in the attributes of the seismic data volumes can be correlated with possible changes in the petrophysical properties of the reservoir. This will allow the operator to monitor fluid movement in the reservoir over time. The use of hydrophone data permits Western to process out the water-bottom multiples and increasing bandwidth, while the three-component geophone data represents both shear-wave (S) and compressional wave (P) seismic data, which help in distinguishing between litho
• CogniSeis was showing its WellTie 2.0, a new synthetic seismogram product derived from the company's earlier comprehensive well log processing and interpretation system, DLPS. WellTie 2.0 provides remarkable functionality in establishing relationships between depth on the well logs and seismic travel time by constructing a synthetic seismogram from well log data and correlating that synthetic to stacked 2D and 3D seismic data. Checkshot and/or velocity survey data can also be factored in to further improve the correlation. Points are then selected and saved to the database or can be exported to be used in other applications. The system also includes numerous project and data management features.
• Among the numerous innovations of Landmark Graphics being exhibited were several geologic interpretation, mapping and reservoir management applications, including StratWorks, for 2D geologic interpretation and well log correlation, and Stratamodel, for 3D stratagraphic geocellular modeling. StratWorks permits asset teams to correlate well logs, build cross-sections, analyze hydrocarbon attributes, and create maps in an integrated environment. It helps a multidisciplinary asset team to make the transition from paper-based projects to the more efficient and accessible tool kit, facilitating productivity, prospect generation, and reservoir management. Stratamodel, on the other hand, was demonstrated as an advanced 3D geocellular modeling system that improves an asset team's understanding of 3D reservoir characteristics and accurately defines hidden reserves in a 3D earth model, identifying potential drilling targets.

• Petroleum Geo-Services (PGS Exploration) showed its new Gulf of Mexico, 2D multiclient calibration project EMC3D, which ties deepwater fields and wildcat wells in four important areas of the Gulf: Mississippi Canyon East (King's Peak MC217, MC383,429, and Mensa MC730), Mississippi Canyon West (Blood, Sweat & Tears MC647, Zeus MC941, and Venus MC852), Green Canyon (Fuji GC506, Sycamore GC472, and Neptune AT575), and Alaminos Canyon (Diana EB945, Hoover AC25, and Baha AC600).

Unusual VSP

Read Well Services has just completed a rather unusual vertical seismic profile (VSP) survey, likely the largest ever on the UK Continental Shelf, for the BP-operated Magnus Field. The survey, shot from a standard anchor-handling supply vessel, took more than 14,000 shots along a 540-km spiral shooting line, which was adopted to avoid boat turn-arounds. A 1650 cubic inch air gun array was used, as well as down hole receivers consisting of an eight-level array of three component, gimbaled geophones. Seven gigabytes of data were recorded and are now being processed.

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