Seismic Interpretation in the Exploration Domain

by Tim E. Smith

Duration: Two to three days

Intended Audience: Entry and intermediate levels

Prerequisites: 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 highly variable 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. The interpretation exercises 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.

Topics covered in the lecture portion include 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, RTM), Wide/Multi Azimuth. Particular reference is given to pre-stack depth migration.
  • Time and depth data in accurate depth
  • Differing characteristics of 2D and 3D data
  • Basic concepts of 2D and 3D interpretation
  • 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 consists of two projects. The first consists of 6 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. These data are used to prepare a structure contour map; and the exercise and course end with a discussion of this map and the overall set of processes used in effective seismic interpretation.

Learner Outcomes:

At the end of the course participants will be able to

  1. Identify the purpose and need for effective seismic interpretation in the exploration domain
  2. Apply the concepts of various types of time and depth seismic migration
  3. Recognize the differences between 2D and 3D seismic data, and how to handle both types
  4. Describe, foundation knowledge of allied seismic topics such as gridding techniques, thin bed analysis, statics, AVO, and inversions
  5. Operate in a rigorous 2D and 3D interpretation project which demonstrates the characteristics of both data types, and the procedures involved in hand mapping data, and projection of them into the workstation environment

Instructor Biography:
Tim E. Smith