Surface Geochemical Information in Petroleum Exploration Integration

G. K. Rise and J. Q. Belt
GeoFrontiers Corporation, Dallas, TX

Modern petroleum exploration has changed into a multi-tool, integrated information science. Leading explorationists have recognized the value of discerning as much reservoir information as possible before making drilling decisions.

While integration efforts have often been a consolidation of “favorite” methods, modern exploration requires a more pragmatic approach. One way to select integration methods is to identify the desired integration results. Since exploration is aimed at detecting and defining petroleum reservoirs, reservoir characterization is the desired integration results.

Reservoir characterization includes basic parameters affecting the commercial value of the reservoir, such as porosity, permeability, reservoir rock type, oil or gas, gravity, petroleum limits and thickness, depth, and detecting the presence of hydrocarbons.

Near-surface geochemical methods, properly implemented and interpreted, can supply information about some reservoir parameters. Case studies from the Eastern Shelf of the Midland Basin will show how modern geochemical methods were applied in exploration to estimate particular reservoir parameters before drilling. In addition to its traditional role of determining the presence and type of petroleum hydrocarbons, near-surface geochemistry has developed into a more comprehensive exploration tool. In several cases, near-surface geochemistry has supplied reasonable estimates of petroleum limits. Even depth and reservoir rock type have been successfully predicted from hydrocarbon composition analysis.

Once reasonable solutions are found for certain parameters, other exploration methods can be employed to determine additional information. At the end of this process, information uncertainty plus missing information, determines exploration risk.

AAPG Search and Discovery Article #90905©2001 AAPG Southwest Section Meeting, Dallas, Texas