Estimation of the Uncertainty in the Hydrocarbon Exploration Through Geographic Information System (GIS). Case of Study: Espino’s Graben , East of Venezuela

Leo Duerto and Darvis Varela
PDVSA, Caracas, Venezuela

This descriptive study presents a methodology that allows the management of great volumes of graphical data and that facilitates the administration, management and planning of projects of oil exploration efficiently.

The methodology is based on the determination of a cell size proportional to the minimum profitable play to explore in an area. This cell is fed with geo-spatial information related to the amount and quality of the existing data. Amounts of information by cell are graphically scaled into five ranks and represent the maturity of knowledge in the area. Similarly the quality of the data (ranked equally) represents the trustworthiness of the data. By means of the weighted combination of the maturity and trustworthiness is created a map of uncertainty of the studied area that can be integrated with additional subsurface information as the elements of the petroliferous system in order to generate maps of risk by cell. This methodology allows in addition integration to geologic exploratory information with socioeconomic data (Earth population, use, vegetation, etc.) of quantifiable way. The integrated evaluation represents maps of the exploratory potential.

In order to demonstrate the effectiveness of the present methodology, a pilot project has been applied to an area in the Espino’s Graben in the central part of Venezuela. In the area, zones of low and average potential have been determined related to zones of high uncertainty. This methodology guarantees the generation of maps synthesis product of the integration of thematic variables, such as: wells, seismic, geochemistry, potential methods, geology, vegetation, population (urban centers), etc. With this space analysis we obtained the measurement of maturity, trustworthiness and uncertainty, which are fundamental maps for the decision making and the exploratory quantification of the hydrocarbon risk.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas