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The programme examines the evidence available and describes the optimum geological conditions for oil formation.
Metadata describing this Open University video programme
Module code and title: S237, "The Earth, structure, composition and evolution"
Item code: S237; 11
First transmission date: 15-08-1981
Published: 1981
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: John Simmons
Contributors: Geoff Brown; John Wright
Publisher: BBC Open University
Keyword(s): Carbon; Debris; Hydro-carbon; Oil
Footage description: Geoff Brown, standing near an oil well in a field in Nottinghamshire, introduces the programme. Brown goes on to examine some cores taken from rock beneath the field on which he is standing. He points out the coal seam in one of the cores and explains how coal was formed. Brown looks next at a core sample of limestone taken below the coal seam. With the aid of animations he explains how these limestones came to have their carbon content. Taking a beaker, Brown collects a sample of crude oil from the oil well. He then holds up a sample of the rock from which the oil was taken. John Wright performs an experiment in the studio in which a sample of crude oil is separated into its constitutents and a red pigment, vanadyl porphyrin, is isolated. Shots of equipment for performing a high pressure liquid chromatography analysis on crude oil. Shots of a graph which shows the results of this analysis. Commentary by Wright points out the Vanadyl Porphyrin peak. He then explains that it is likely that vanadyl porphyrin is a product of the breakdown of chlorophyll and, as such, strong evidence for the plant origins of crude oil. Over film shots of oceanic plankton and over a series of animations, Wright explains why plankton is the likely source for crude oil and how these unicellular plants are broken down under the right temperatures to form a variety of crude oils and natural gases. Wright goes on to explain, with the aid of graphs and diagrams, that crude oil production is restricted to an area of the lithosphere between one and four kilometers deep. At the higher temperatures found at greater depths, he explains any oil formed is quickly broken down while at the lower temperatures in shallower areas oil is not formed at all. Wright also stresses that time as well as temperature is an important ingredient in crude oil production. Wright shows a summary diagram based on information from all the world's oil reservoirs which show the boundaries of temperature and depth at which oils are formed. This, he points out, corresponds well with the theoretical values. With the aid of a map of the world, John Wright points out areas of greater oceanic plankton production. He explains that some areas such as the continental shelf off Peru have as much as 11% of organic carbon in the sediment. Wright goes on to speculate that a knowledge of plate tectonics may help to predict the locations of ancient oil fields. Back in the Nottinghamshire oil field, Geoff Brown summarises the programme.
Production number: FOUS164A
Videofinder number: 1599
Available to public: no