ABSTRACT: Uncertainty of petroleum generation using methods of experimental design : application to the Gippsland basin, Australia

Wendebourg, Johannes¹, Keith Mahon², and Christopher Tapscott²
(1) IFP, Rueil-Malmaison, France
(2) Exxon Production Research, Houston, TX

Experimental design and response surface modeling techniques generate a regression model approximation of the results of thermal maturity models such as generated hydrocarbon volumes. Uncertainty is determined by Monte-Carlo sampling of the response surface instead of the thermal model itself which would be considerably more expensive. Advantages are that interaction effects are taken into account, that parameters are ranked according to their influence on the response suggesting those parameters that may be discarded, and that the response surface can be constrained to temperature and maturity data thereby defining the valid parameter space and reducing the uncertainty of the generated volume.

As an example application, the uncertainty of petroleum generation from source rocks in the Gippsland Basin, southeast Australia, is calculated using 1-D thermal and maturity modeling. Main parameters are heat flow history and thermal conductivity contrast. A linear screening design shows that heat flow history has the main effect on petroleum quantities generated and calibration to available temperature data allow to fix present day heat flow. The resulting second-order response surface is based on heat flow during rifting and coal content. Petroleum generated from the total sediment column is between 70 and 110 kg per square m. This result was obtained with 26 model runs. An additional exhaustive screening of the parameter space corroborates these results.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia