简介：通过新一代数据软件，地质工作者将能够在计算机辅助解释流程中，加载入地震和岩石物理数据。井数据和地震数据的接合，强化了各自的功能。综合交叉以及地质关联方案，能够对地球物理工作者相互协作有很大帮助。对孔隙压力预测，油气指示，油井孔隙度等的解释处理，都可以使用这些地震资料数据。

While multiple disciplines of professionals such as geologists, geophysicists, drillers, and engineers have been integrated into unified asset teams, integration of their respective software applications has lagged behind. Today, seismic data is being combined with geologic cross-section data, resulting in a new generation of software for more intuitive, multidisciplinary interpretation of subsurface features.

Geophysicists currently enjoy excellent 3-D visualization tools for interpreting seismic surveys, and these software applications are already integrated with multiple well databases for viewing wells in this same context. The addition of new geologic interpretation functionality to this environment will provide geologists with powerful computer-assisted techniques.

Integration of applications in next-generation software

This next generation of software incorporates geologic cross-sectioning and geologic correlation applications that are fully integrated with current seismic interpretation and well data applications. Results from this solution demonstrate that integration of geology, seismic, and petrophysical data offers new opportunities for subsurface interpretation, including improved seismic-to-well ties, confirmations of seismic facies classifications, marker-constrained interpretations, and the initiation of reservoir model development.

The level of integration provides geologists easy access to seismic data and useful operations on this data, including the creation of “lines of section” (LOS) in a shared base map and making these lines of sections immediately available for geologic cross-section creation and correlation. The lines of section can be drawn through wells or bottomhole locations or any other marker in the well. Figure 1 shows a simple traverse through three offshore Indonesia wells.

When wells are deviated or horizontal, the lines of section can be defined close to the zone of interest in each well so that seismic data extracted from 3-D datasets will also be very close to the zone of interest, which minimizes errors caused by projecting wells onto seismic lines. Since the seismic applications can be used to interpret multiple 2-D and 3-D seismic surveys, the lines of section can be defined along 2-D seismic lines, 3-D inlines and crosslines, or well locations and free map points.

Once an LOS has been defined with its references to wells, seismic lines, and free points, the cross-section and correlation modules can extract seismic and well data directly from the data repositories together with seismic interpretation, synthetics, and well interpretation data. The well data can include any processed or derived logs created by petrophysical applications as well as edited recorded logs. The seismic data accessed may be seismic amplitude data suitable for conventional seismic interpretation, or it may be a seismic pore pressure prediction volume, porosity volume, or hydrocarbon indicator volume. Geologists may find new ways to interpret once they have easy access to such data and can integrate it with all the well data in their cross sections and interpretation.

This may be Variable Area/Wiggle Trace as shown here, or a variable color scheme may be used. Other features that can be incorporated into the display are the processed log curves, image logs, well schematics, stratigraphic columns of chronostratigraphy or lithostratigraphy, computed log curves including lithology estimates, synthetics, seismic horizon and fault interpretation, and fluid contacts.

Once the well and seismic data are combined in the cross-section view, the seismic intervals and the associated seismic interpretation can be used to constrain or guide well marker correlation when using manual and computer-assisted correlation methods. The cross section can be used to edit previous seismic interpretations or create a new interpretation. This new view enables new markers to be defined or edited, and the lithology or deposition environment along the well can be redefined. In addition, geocellular model data and well schematics can be added to the section. Interpreters of pore pressure prediction volumes often ask to see casing diagrams of real and proposed wells integrated into cross sections to aid interpretation. The interpreter may define fluid zones using well logs, seismic data, and structural information provided by the interpretation. The vertical domain of the cross section can be either time or depth.

Figure 3 shows a well correlation panel with an example well schematic. Such panels may retain horizontal scale and may contain a few wells, as in this case, or hundreds of wells. Interpreters can use both the well correlation view and the cross-section view to help the geologic correlation process. Seismic data in the backdrop of the cross section provides insight for the well correlation activity but will tend to reduce the number of wells in view.

Geologic correlation in this type of geosciences software environment can be enriched with many features to aid correlation and increase productivity. Rules can be developed to perform computer-assisted correlation that incorporates any chronostratigraphic, lithostratigraphic, and biostratigraphic information available while comprehending geologic faults.

Computer-assisted methods can highlight features such as dunes, channels, and erosion to make interpretation easier. A well template editor defines any number of tracks to improve ease of use and consistency in the displays. Once the interpretation is complete, high-quality preview and hard-copy capabilities enable the asset team members to present their findings to colleagues.

The wells have gamma ray logs displayed in color as a lathe display along each borehole. A blue marker has been interpreted just above the seismic horizon at the base of a sand formation. In this view there are about 1,970 ft (600 m) of relief on this horizon. The interpreted seismic horizon reduced the interval of log data the interpreter needed to examine for each correlation.

Deviated and horizontal wells

The dataset used in this project represented near-vertical wells, but deviated and horizontal wells may be displayed in a 3-D view with equal ease. Interwell sections between deviated and horizontal boreholes may also be displayed. These sections are curvilinear and may show any seismic attribute extracted from a 3-D volume along their surfaces. This allows interpreters to follow the seismic data between two deviated or horizontal wells just as easily as for vertical wells. Interpretation from the 3-D volume can also be extracted along these surfaces between the wells. This enables log interpreters to correlate horizontal boreholes in 3-D with the assistance of seismic interpretation, thus avoiding a lot of mental gymnastics required to correlate measured depth from independent deviated boreholes while trying to visualize where each zone of each borehole lies in 3-D geology space.

To assist the geologist in this task, the 3-D view was given a huge vertical exaggeration. This allows log curves, which may be lathe or conventional curve displays, to be viewed in detail while reducing the spatial separation between the wells. Log curves may be displayed orthogonally to the borehole, and interpreted markers may be shown orthogonally to the borehole when correlating or with true dip when trying to understand stratigraphic versus structural dip.

Integrated interpretation

As illustrated, display of the seismic and well data together strengthens the interpretation of both. Subtle, uninterpreted faults indicated by the well data can be interpreted on the seismic data, and changes in the patterns in the seismic data can influence the stratigraphic interpretation of the well data.

Summary

An integrated cross-section and geologic correlation solution with live access to seismic data and live interpretation features promotes new levels of collaboration between geoscientists. Integration of predicted pore pressure, hydrocarbon indicator, or porosity volumes with well data encourages use of these derivative seismic volumes. 

杨宝剑 是振威（全球）石油网的高级技术编辑，在石油技术资讯行业有八年的学识和经验。他源源不断地提供石油行业全球最新的技术创新、研发成果、现场应用情况等信息。如果你对该项新技术有任何的疑问，或者对“新技术新产品”未来的内容有任何问题或建议，请联系杨宝剑编辑 +86 10-58236512 Email：allenyo@zhenweiexpo.com 欢迎与行业互动！