--> ABSTRACT: Sensitivity/Risk Assessment with Basin Models: Approach and Case Example from a Frontier Setting, by R. H. Lander, V. Felt, and L. Bonnell; #91021 (2010)

Datapages, Inc.Print this page

Sensitivity/Risk Assessment with Basin Models: Approach and Case Example from a Frontier Setting

LANDER, R. H, V. FELT A, and  L. BONNELL

Most basin modeling studies are conducted using a set of 1most likely' input parameters that are tuned to fit available calibration data. While such studies can provide useful qualitative insights into controls on the hydrocarbon system they cannot be applied rigorously to evaluation of risk. In this study we investigated a number of key input parameter uncertainties for a frontier region characterized by a single calibration well. The purpose of the study was to determine the uncertainties in model predictions of the extent and timing of hydrocarbon generation and oil to gas cracking. We reconstructed the history of erosion/deposition, compaction, structural displacement, isostatic and tectonic subsidence, heatflow, temperature, hydrocarbon generation, and oil to gas cracking for a cross section using BMT 3.3.

In all we constructed over 60 "optimized" models that agreed with the calibration well data to within measurement uncertainties. These models explore the effect of the following input uncertainties in model predictions: time to depth conversion factors; the number, magnitude, and timing of erosional events; the magnitude and timing of rifting events and associated heatflow pulses, crustal and subcrustal properties affecting subsidence, background heatflow values, thermal conductivities of lithologies, kerogen to hydrocarbon transformation kinetics, and vitrinite reflectance models.

Uncertainties in the timing of hydrocarbon generation vary greatly over the modeled section. In general predictions for the deep kitchen and shallow platform areas are comparatively insensitive to input parameter uncertainties. In intermediate locations, however, the extent of hydrocarbon generation and oil to gas cracking varies greatly and is most sensitive to the history of erosion; the heatflow history, and the oil to gas cracking kinetics. For the study area large uncertainties in the following factors had little effect on the predictions for the optimized models: time to depth conversion, crust/subcrust properties, background heatflow, thermal conductivity, kerogen to hydrocarbon transformation kinetics, and vitrinite reflectance algorithm.

AAPG Search and Discovery Article #91021©1997 AAPG Annual Convention, Dallas, Texas.