Cooking Up CrudeFormation of Oil and Natural Gas

How did crude oil and How did crude oil and natural gas form?natural gas form?

Concept: The oil and natural gas taken from the earth’s crust today originated as microscopic plants and animals that lived in the ocean millions of years ago.

You will need:You will need:

PaperPencilsMap pencils, crayons, or markers

Make space on your Make space on your table to draw.table to draw.

Fold your paper into three equal sections by drawing two lines across the width of the paper.

LabelLabel

Label the sections: Scene One, Scene Two and Scene Three.

History of Formation of History of Formation of Oil and Natural GasOil and Natural Gas

I am going to tell you a story about the history of the formation of oil and natural gas in Oklahoma.

Draw a picture of what Draw a picture of what you hear.you hear.

570 million years ago-during a period known as the “Paleozoic Era” a large sea covered the area we now call Oklahoma. In this sea lived a vast number of microscopic plants and animals called plankton. This microscopic plankton drifted on or near the surface of the water and became so numerous that it could actually be seen with the naked eye.

Real PlanktonReal Plankton

Cartoon PlanktonCartoon Plankton

Paleozoic Era SeaPaleozoic Era Sea Throughout the “Paleozoic Era” the sea was

also alive with trilobites, corals, crinoids, brachiopods and many other plants and animals which evolved over millions of years.

A trilobite was a strange-looking little creature. Small grooves divided its body and hard segmented shell into three vertical parts. Its head was covered by a semicircular shield.

TrilobiteTrilobite

CoralCoral Coral, which still exists today, came in many

different sizes, shapes and colors. The coral polyps were simple animals that were able to take calcium out of saltwater and convert it into a rocklike shelter, in which they lived.

CrinoidsCrinoids Crinoids anchored themselves to rocks on

the sea floor with a root-like structure that supported a stalk or column topped by a cup-like cavity, which formed a protective case for a flower.

BrachiopodsBrachiopods Brachiopods were clam-like animals. Their

two-piece dorsal and ventral shells enclosed and protected their soft body parts.

Wichita and Arbuckle Wichita and Arbuckle Mountains of Mountains of

OklahomaOklahoma During this same time period, there was a

great mountain range much like the Colorado Rockies, which ran along the edge of the sea. It was one of the tallest mountain ranges on earth and was actually connected to the Rockies. Today we call these ancient mountains the Wichita and Arbuckle Mountains of Oklahoma.

South Mountain, South Mountain, Wichita Mountains, Wichita Mountains,

OklahomaOklahoma

Turner Falls, Arbuckle Turner Falls, Arbuckle Mountains, OklahomaMountains, Oklahoma

Sediments ended up in Sediments ended up in the sea with the the sea with the

creatures.creatures. As the wind, rain, avalanches and ice

movements eroded the Wichita and Arbuckle Mountains, tiny particles—called sediments—were carried into the sea where the billions of tiny sea creatures lived. Wind and rain also carried sediments from other parts of the world.

Layers of Sedimentary Layers of Sedimentary RockRock

I suddenly have a I suddenly have a sinking feeling.sinking feeling.

Plankton and other Plankton and other sea life died and sank.sea life died and sank.

Due to their ability to reproduce quickly, the plankton, along with other sea life, were abundant. As these carbon–containing organisms went through their extremely short life cycles and died, their remains sank to the deep sea floor and became covered with the mud, sand and sediment from the eroding mountains and surrounding areas. Because they were buried so quickly on the deep sea floor, the plankton and other sea creatures lacked oxygen, which is necessary for decay (or decomposition).

Can you picture this Can you picture this scene?scene?

Now it is your turn. Draw scene 1: Oklahoma’s Wichita and Arbuckle Mountains partially covered by a sea containing plankton and other sea creatures.

Chapter 2Chapter 2

320 million years passed, and the layers of sediment on the sea floor became thousands upon thousands of feet deep. These layers were filled with dead plankton, fossilized sea creatures and eroded rock!

Mesozoic EraMesozoic Era

During this time period—known as the “Mesozoic Era”—dinosaurs began to roam the earth and swim in the sea. More than half of the great sea had disappeared because of evaporation, earthquakes, and the filling and layering of sediments on the sea floor.

PlesiosaursPlesiosaurs

The mountain range was significantly smaller because of millions of years of erosion. The continued accumulation of sediments in the sea buried the organic-rich layers deeper and deeper, creating immense heat and pressure.

This heat and pressure was responsible for changing the dead organic material into hydrocarbons (substances containing hydrogen and carbon) causing the remaining inorganic material to change into sedimentary rock.

Can you picture this scene?

Organic material Organic material became hydrocarbons.became hydrocarbons.

Picture scene 2.Picture scene 2. This heat and pressure was responsible for

changing the dead organic material into hydrocarbons (substances containing hydrogen and carbon) causing the remaining inorganic material to change into sedimentary rock.

Can you picture this scene?

Scene 2 pictures.Scene 2 pictures.

Cenozoic EraCenozoic Era 250 Millions years later brings us to

present day- the “Cenozoic Era”. Man now walks the earth and the dinosaurs have long since disappeared. The erosion from the mountains and other sediments have now completely filled the great Oklahoma Sea. The Wichita and Arbuckle mountain ranges are much smaller and no longer connected to the Rockies, or each other. Shifts in the earth’s surface have also affected the size of the sea and mountains over these millions of years.

Eroded Wichita Eroded Wichita MountainsMountains

Creating Oil and Creating Oil and Natural GasNatural Gas

The heat and pressure have formed many layers of sedimentary rock, and deep source rock (rock where oil and natural gas form). Much of the water that was in the sea is now in the pore spaces of the sedimentary rock. The remaining water evaporated or was pushed into areas where seas or oceans now exist.

Over millions of years, temperatures ranging from 150-300 degrees Fahrenheit have cooked the organic materials causing a complex chemical change, creating hydrocarbons called oil and natural gas. These hydrocarbons, also known as fossil fuels, have been produced in 71 of Oklahoma’s 77 counties.

Draw scene 3.Draw scene 3.

CommunicateCommunicate

Using the pictures you have drawn, tell how oil and natural gas are formed.

SummarySummary Much of what is Oklahoma today was under an

ancient ocean millions of years ago. Geologists believe this because many rock layers containing fossil remains of marine life have been found throughout the state. Millions of microscopic marine plants and animals which lived in the waters eventually died and settled on the ocean floor. The dead plants and animals were often buried by sand and other sediment. Heat from beneath the earth’s crust “cooked” the plant and animal remains forming oil and natural gas deposits within the rock layers. This is why oil and natural gas, or petroleum, are called fossil fuels.