Topic G4 : EARTH MATERIALS AND NATURAL RESOURCES Key Idea 2:Permeable rocks offer pathways for oil and gas migration; highly porous rocks can act as natural reservoirs for underground supplies of oil and gas Knowledge and Geological techniques Comments understanding and skills a. Porosity and permeability Analysis of rock textures in of rock and sediments terms of porosity and affects the presence, permeability (grain size, distribution and migration shape, packing, sorting; of fluids (water, oil and cementation); primary and natural gas): secondary porosity. primary/secondary porosity in rock; factors that affect porosity and permeability. b. Fluid flows in rocks and Application of to Candidates will be required Darcy’s Law sediment can be model fluid flow: to apply, but not recall, modelled using to measure Darcy’s Q = Darcy’s Law −   kA Law. fluid flow in rocks.   L For exemplification of see Darcy’s Law Mathematical Guidance for A level Geology. c. Oil and gas migration are Analysis of geological cross- controlled by geological sections through oil and factors: migration paths natural gas bearing structures. – relative buoyancy of oil and natural gas; structural and stratigraphic traps for hydrocarbons; reservoir rocks and cap rocks. d. The characteristics of Analysis of the controls on Candidates are expected to subsurface geology groundwater quality which have studied the differing which control the flow of result from geochemistry geologies associated with groundwater (carbonates and sulfates), the formation of springs. (hydrogeology) include aquifer filtration, residence confined and unconfined time and sources of pollution. aquifers, aquicludes, aquitards, the water table, piezometric surfaces, cones of depression and recharge zones.
Topic G4 : EARTH MATERIALS AND NATURAL RESOURCES Key Idea 2:Permeable rocks offer pathways for oil and gas migration; highly porous rocks can act as natural reservoirs for underground supplies of oil and gas Knowledge and understanding Geological techniques and skills Comments a. Porosity and permeability of rock and sediments affects the presence, distribution and migration of fluids (water, oil and natural gas): primary/secondary porosity in rock; factors that affect porosity and permeability. Analysis of rock textures in terms of porosity and permeability (grain size, shape, packing, sorting; cementation); primary and secondary porosity. b. Fluid flows in rocks and sediment can be modelled using Darcy’s Law. Application of Darcy’s Law to model fluid flow: Q =  kA   L  Candidates will be required to apply, but not recall, Darcy’s Law to measure fluid flow in rocks. For exemplification of Darcy’s Law see Mathematical Guidance for A level Geology. c. Oil and gas migration are controlled by geological factors: migration paths – relative buoyancy of oil and natural gas; structural and stratigraphic traps for hydrocarbons; reservoir rocks and cap rocks. Analysis of geological cross- sections through oil and natural gas bearing structures. d. The characteristics of Analysis of the controls on Candidates are expected to subsurface geology groundwater quality which have studied the differing which control the flow of result from geochemistry geologies associated with groundwater (carbonates and sulfates), the formation of springs. (hydrogeology) include aquifer filtration, residence confined and unconfined time and sources of pollution. aquifers, aquicludes, aquitards, the water table, piezometric surfaces, cones of depression and recharge zones. −
Geology%20Eduqas%20A%20level%20Guidance%20for%20Teaching%20word%20version.docx