Nelson, Ronald A., Amoco, Exploration & Production Technology Group, Houston, Texas

Abstract: Integrated Structural Geology Techniques and How They Constrain Exploration Risk

In petroleum exploration, structural geology plays a critical role in identifying, defining, and quantifying hydrocarbon traps and in assigning technical risk to those prospects. This is done through the application and integration of up to 20 diverse structural techniques. These techniques each have an appropriate time of application and impact in the life of a prospect from inception to development drilling. Each play or prospect requires a unique subset of these techniques applied in a proper sequence. Several structural project plans will be shown using specific prospects as examples of how these techniques are chosen and applied.

The techniques that are most important in our plays today are those that constrain exploration risk parameters. The Amoco exploration risk process will be presented as an example of such a risk process. That process is used to show how particular structural techniques help quantify several of the critical risk parameters. These risk parameters include (1) trap definition or the properties of the hydrocarbon container (position, depth, size, and shape), (2) trap timing relative to hydrocarbon generation and migration, (3) seal integrity, and (4) reservoir porosity and permeability as influenced by deformation. A typical structural prospect will be utilized to depict the quantitative impact of the application of particular techniques on the assignment of final risk numbers used in drilling decisions. In my opinion, the judicious application of a variety of modern structural geology techniques has the largest impact in quantifying and risking the prospect portfolios of the major oil companies of today.

AAPG Search and Discovery Article #90934©1997-1998 AAPG International Distinguished Lecturers