Lecture 19 resources 10 Flashcards
Which is the largest refinary in the UK
Esso refinery in Fawley - near soton.
processes around 270,000 barrels of crude oil a day, provides 20 % UK refinery capacity.
who were the major producers of oil 2019/2020
US
Saudi Arabia
Russia
Canada
China
Iraq
who were the major consumers of oil in 2019/2020
US
China
India
Japan (doesn’t produce so heavily reliant)
Russia
What is unconventional gas
Shale gas
- tight gas, trapped in low porosity, permeability silt and sand
- coal bed methane (coal deposits give off methane as they form)
- methane hydrates (freezing of petroleum on shelf of sea floor)
what is unconventional oil
Oil shales
oil sands, heavy oil and bitumen
synthetic crude products
liquids from natural gas
how do you release trapped shale gas resource?
fracking - there has been strong push back against this.
geology of generation of petroleum
organic rich source rock (is burried)
release oil into reservoir
rocks with permeability to store and transport oil
seal on top to prevent oil escaping.
How does organic rich material become petroleum
take phytoplankton
burry with depth,
also increased temperature
Kerogen -> oil -> gas
there is an oil forming window
Kerogen types and chemical evolution
what are the fragments, could be woody, algae
this controls how it will evolve - will it give oil, gas or nothing.
What controls the maturation of oil and gas
temperature
pressure
nature of the organic material
What is determination of thermal maturity
work out what temp and pressure they have been heated to.
can look at colour - to understand how mature the rocks are.
Whats migration (oil and gas)
oil and gas escape from source rocks, migrate into reservoir rocks - gas accumulates in deposits.
- oil and gas flow towards the surface, they are less dense than water - fills up most of the porosity int he upper crust.
hydrocarbon traps are reservoirs with impermeable caps that impede upward migration.
What are the key attributes of a reservoir rock
Porosity and permeability
Explain porosity of reservoir rock
porosity = measure of rock’s ability to hold fluid.
porosity, open space in a rock divided by total rock volume - expressed as a % of total rock - taken up by pore space.
example: sandstone = 8% porosity with 92% solid rock and 8% open space - containing oil, gas or water (this is the minimum porosity for hydrocarbon.
explain permeability of rock
Permeability - measure of resistance to flow of a fluid through a rock - if it passes through the rock easily = high permeability, typically measured in mili darcys permeability may be classified as:
< 10md fair
10-100 high
100-1000 very high
>1000 exceptional
