MILWOOD-HARGRAVE, M., and A. M. FRANCIS*, Ikon Geoscience, Twickenham, Middlesex, England

ABSTRACT: Virtual Exploration

With the now commonplace implementation of interactive interpretation workstations, the process of generating a time model for a prospect has been simplified and accelerated. This paper shows that for many structural traps, the critical interpretation steps are in subsequently generating a valid depth model, evaluating the depth structure, and being able to realistically assess confidence limits of the model. The development of a comprehensive velocity model is a key element of any depth conversion. Lateral velocity variations across an area are capable of generating structures where the time interpretation is flat. An example is shown in this paper, and the effect of altering the velocity field and the resulting changes to the structure are described. Forward and inverse modeling are used to show that the structure is more favorable than was first expected from the depth conversion.

From this example, the idea of sensitivity testing of a number of simple structures is developed. A fully interactive ray trace modeling system integrated with an interpretation workstation allows different confidence limits to be rapidly tested and evaluated.

By extending the model into the third dimension, specific scenarios can be constructed in three-dimension (3-D) and uncertainty limits tested on a complete reservoir. Further than this, the construction of type models in 3-D allows the concept of "virtual exploration" to be realized, whereby specific exploration concepts can be investigated and tested. The virtual exploration model, and its associated seismic data set, form an ideal educational, planning, and training tool for all levels of geophysicists and geologists.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.