Uncertainty in geoscience interpretation : statistical quanatification of the factors that affect interpretational ability and their application to the oil and gas industry

Understanding the subsurface through geological modelling is extremely important to modern civilisation, e.g. the extraction of resources and the geological storage of wastes. Geological data are commonly sparse, with the result that geological models are under-constrained and multiple structural in...

Full description

Bibliographic Details
Main Author: Macrae, Euan John
Published: University of Strathclyde 2013
Subjects:
624
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576426
Description
Summary:Understanding the subsurface through geological modelling is extremely important to modern civilisation, e.g. the extraction of resources and the geological storage of wastes. Geological data are commonly sparse, with the result that geological models are under-constrained and multiple structural interpretations are often valid. Geoscientists are also affected by cognitive biases, so individual interpretations may not be equally likely. A better understanding of how geoscientists should be trained, and what interpretational approaches are most effective, is therefore required. An international sample of more than 700 geoscientists, with varying technical backgrounds, and experience levels, was collected. Six reference experts were then recruited to interpret the same seismic image, allowing a scoring system to be formed to evaluate respondents' interpretations. Statistical analysis of the sample showed that respondents' experience was more influential than their education and work environment in terms of producing a valid interpretation. However, interpretational techniques relating to 'thinking about geological time' were even more influential than respondents' experience. The fact that certain techniques were statistically significant in addition to respondents' experience shows that training is important regardless of experience level. In addition to the large sample, a separate workshop experiment, utilising a control group, was conducted with 49 industry geoscientists. Analysis of the data from the workshop identified a causal link between 'considering the geological evolution' and 'producing a valid interpretation'. Finally, based on the results, and the analysis of relevant literature, an interpretation workflow was derived for the oil and gas industry. The workflow mitigates cognitive biases, improves team work, validates multiple interpretations and captures interpreters' evolving assumptions. Thus, this research advances the understanding of how risk arising from uncertainty in geoscience interpretation can be mitigated, and how geoscience teaching and practice can be improved.