Seismic Interpretation in the Exploration Domain

by Tim E. Smith

Duration: Two to three days

Intended Audience: This course is primarily designed for explorationists/earth scientists who are advanced students, larger company personnel with 1 to 5 years of experience, and independent operators. The overall experience is directed towards optimization of seismic interpretation with regard to tightening budgets and increased expectations in the current hydrocarbon pricing environment.

Summary:
This two day course provides a robust background in both the fundamentals and advanced aspects of 2D and 3D reflection seismic interpretation. It is divided into two essentially equal portions: the first consists primarily of lectures and associated exercises, and the second consists of 2D and 3D seismic interpretation projects designed to illustrate many of the concepts and techniques of seismic interpretation discussed in the lecture portion.

Course Outline:

Topics covered in the first day consist of the following

• The purposes and goals of seismic interpretation
• General concepts and concerns in seismic interpretation
• Description and sensitivity of seismically derived velocities
• Seismic migration: Time, Depth (Kirchoff, Wave, Beam Steer), Wide/Multi Azimuth particular reference is given to pre-stack depth migration
• Vertical depth conversion of 2D and 3D time migrated data
• 2D vs. 3D seismic data interpretation techniques
• Grid guidelines and limitations in mapping
• Thin bed resolution and analysis
• Statics corrections for land data
• AVO and amplitude anomalies
• Generation and use of seismic inversions

The interpretation portion (second day) consists of two projects. The first consists of five 2D lines from a complex structural region. This exercise involves tying these data with recognition of the limitations associated with the 2D format. The second consists of 15 lines from a 3D project covering the same region; some of the 3D lines overlie the 2D data and provide direct comparison between the two data sets. Students prepare a structure contour map from the 3D data; and the exercise and course end with a discussion of this map and the overall set of processes used in effective seismic interpretation.

Students use paper data because direct hands-on methods provide the best overall educational experience. They also avoid problems of non-familiarity with various software packages and licensing issues. The interpretation techniques which are demonstrated and employed in these exercises can later be effectively transposed to the workstation environment.

Learner Outcomes:

• Explain the philosophy and goals of seismic interpretation in a hydrocarbon exploration environment
• Employ practical knowledge of post-stack and pre-stack time and depth migration, and applicability to interpretation projects
• Contrast and compare significant topics in interpretation – velocity analysis,differences between 2D and 3D data, mapping styles, thin bed analysis, inversion, AVO, and statics
• Interpret of 2D and 3D seismic data; maps based on the 3D interpretation

Instructor Biography:
Tim E. Smith