ENERGY/GEOLOGY 101

Energy is the capacity of a physical system to perform work. Hitting snooze on the alarm clock, the
commute to work, making dinner in the evening–all of these functions require energy.

There are two types of energy:

• Potential Energy: Stored
• Kinetic Energy: Working

Energy sources such as coal, nuclear and hydro, can be categorized as renewable or nonrenewable. Renewable energy sources (i.e., solar, wind, geothermal, biomass, hydropower) can be easily replenished. Nonrenewable energy sources (i.e., oil, natural gas, coal) are sources we expend and cannot be replenished. As of today, only 7% of the energy we use comes from renewable energy. We get most of our energy from nonrenewable energy sources.

Oil and Natural Gas
It has been a long-term myth that oil comes from dinosaurs. Oil, natural gas and coal are types of hydrocarbons. These hydrocarbons are formed from decaying plants and animal matter from millions of years ago. Over time, layers of mud and rock covered this organic matter and pushed it deeper into the Earth’s surface. The plant and animal matter slowly turned into hydrocarbons due to pressure, high temperatures and lack of oxygen. Crude oil is a mixture of carbon, hydrogen, sulfur, nitrogen, oxygen, metals and salts.

Underneath the Earth’s surface, natural gas is composed of mostly methane but also contains other hydrocarbons such as propane, ethane and butane. Most of the natural gas we use in our homes is composed only of methane. Within natural gas processing facilities, the other hydrocarbons are removed.

Resources | Home

Locating Oil and Natural Gas
Geologist use a process called seismology to locate oil and natural gas underground. Shock waves are delivered into the ground by a vibrator attached to a large truck. Geophones are placed at the surface to record the rate and strength of the sound waves reflected back from underneath the ground. Depending on the type of rock the sound waves encounter, the reflection rate will vary in speed and strength. Computers are then used to map out the underlying surface. Today, new high definition technology allows us to reprocess original 3D seismic data and view a more accurate imaging of these reflected waves. This new imaging data may help us locate potential oil and gas reservoirs that were previously undiscovered.

Underneath the Earth’s Surface
Another long-term myth is that there are rivers and lakes of oil below the surface. Hydrocarbons are located in the small holes between the grains that make up the rock. The connectivity of the holes in the rock often determine certain processes used when drilling for oil and natural gas. Permeability is the measurement of how easily fluid can move through a volume of rock. Darcy is the unit of measurement; the higher the number, the easier fluid moves through the rocks. Rocks with poor permeability (a low darcy measurement) are considered tight. These rocks are often fracture stimulated (fraced) to increase permeability and allow the flow of oil and natural gas to easily move through the rock.

To read more about the oil and gas process please visit our Oil and Natural Gas Glossary by clicking here