Earth and Environmental Science

9.6 Option — Organic geology 3. Searching for coal and oil

Syllabus reference (October 2002 version)
3. Searching for coal and oil	*Students learn to:* describe the exploration methods used to determine the existence and extent of coal deposits describe the exploration methods used to determine locations of oil, including geophysical methods and drilling identify the location and main geological features of known coal and oil localities and relate this to the search for new ones	*Students:* gather information from secondary sources to outline the methods and technologies used to locate fossil fuel reserves

Extract from Earth and Environmental Science Stage 6 Syllabus (Amended October 2002),© Board of Studies, NSW.

[Edit 21 Oct 04]

Prior learning: Science Stages 4–5 Syllabus: Outcomes 4.11 (content 4.11.1 c ), Outcome 5.11 (content 5.11.1 b).

gather information from secondary sources to outline the methods and technologies used to locate fossil fuel reserves

Gather information from geology textbooks and mining books, as well as on the Internet. Use a search engine with words such as ‘fossil fuel reserves’, ‘geophysical’ and ‘drilling’.
Record the information you find in a table with headings such as ‘Method/Technology used’, ‘Types of Reserves’ , ‘Location’,

describe the exploration methods used to determine the existence and extent of coal deposits

describe the exploration methods used to determine locations of oil, including geophysical methods and drilling

Exploration methods used to determine coal deposits and oil and gas accumulations are the same so both dot points are covered below.
Obtain a legal exploration title to assess the potential area.
Gather geological information already known on the area (i.e. a literature survey).
Perform surface exploration; e.g. field mapping, surface geophysics i.e. gravity, magnetic, electromagnetic and seismic reflection.
Perform subsurface exploration; e.g. drilling, chemical and physical analysis of coal samples from drill cores, geophysical logging of coal or petroleum bores.
Estimate coal or petroleum resources and the significance of geological factors in extraction.

identify the location and main geological features of known coal and oil localities and relate this to the search for new ones

Permian and Mesozoic age coals are found in South Africa, South America, India, Antarctica and Australia.
Permian and Mesozoic coals are all similar in composition.
Coals formed in the Carboniferous period are located in the Northern Hemisphere.
Carboniferous coals differ from Permian and Mesozoic coals as their content of sulphur is greater.
The search for new coal deposits would use the above information to target potential geological sequences that were deposited under coal forming environments, e.g. the search for a new coal deposit in the Sydney Basin would begin by identifying strata deposited in the Permian age under a coal forming environment (sandstone or shale rock type).
There were two main episodes of oil source rock deposition.
These occurred during the Paleozoic era peaking around the Devonian period, and the Mesozoic era peaking around the Cretaceous period.
Paleozoic petroleum only accounts for 13% of the current total global reserves. The hydrocarbon potential of these rocks has not been fully explored.
In Australia, hydrocarbons are produced from oil and gas fields in the Gippsland Basin, Cooper Basin, Perth Basin, Northwest Shelf (including Canning Basin and Bonaparte Basin) and Bass Strait (including Otway Basin).
The search for new oil and gas accumulations would use the above information to target potential geological sequences and traps that were formed during the Paleozoic and Mesozoic eras, under typical petroleum forming environments.