**7. References**


**7** 

*Portugal* 

Nuno Luis Madureira *ISCTE-IUL, CEHC* 

**Estimating Oil Reserves: History and Methods** 

When human societies became aware that an increasing proportion of their power, heat and light were produced from fossil fuels and that fossil fuels were an exhaustible resource, there was no way back to the pre-industrial world. Drawing on the history and methodologies of estimating petroleum reserves this chapter explains how geologists, politicians, engineers, managers and the public at large have come to perceive the finite

On the technical side, the need to assess petroleum reserves fostered scientific advances in the domain of the stratigraphic study of rock reservoirs, in terms of the geological understanding of petroleum origins and formation, in the domain of statistical forecasting based on data from producing wells as well as in geophysical measurements. However, the path from measurement technique capacities towards a set of final aggregate figures proved anything but linear. From the outset, the estimation of reserves took place within the framework of a web of political stances, business and social interests and economic organizational realities. What sway did these forces hold over the course of events? What came to determine the core choices about the classification of reserves and the assessments of undiscovered petroleum? Furthermore, how relevant did the contribution of science and technology prove? To answer these questions the ensuing pages sketch the state of the art in geological surveying at the dawn of the twentieth century before examining the technology available for oil discovery and closing with a comparative view of the institutional scenario

**2. Volumetric methods and statistical methods: The first oil survey** 

The completion of the first oil survey unleashed generalized fears of imminent depletion in the United States (U.S.). Much in line with what had previously happened with coal surveys in Britain, key advances in the knowledge on fossil fuel stocks spread alarm about the finiteness of non-renewable resources. As early as 1909, Americans realized that oil wells might rapidly dry up and all the more so when the boom in automobiles could only worsen the situation.

The first national estimate of oil resources was commissioned from the U.S. Geological survey and integrated into the national inventory of mineral wealth conducted under the

**1. Introduction** 

nature of energy sources.

prevailing over the classification of oil reserves.

**2.1.1 Volumetric methods and statistical methods** 

