Petroleum (or crude oil) is a naturally occurring liquid mixture of hydrocarbons, but containing some compounds of oxygen, nitrogen and Sulphur. It is an oily, thick, flammable, usually dark-colored liquid ,commonly obtained by drilling, used in a natural or refined state as a fuel and separated by fractional distillation into gasoline, naphtha ,benzene ,kerosene ,paraffin etc. It is often referred to as the “black gold.This name itself is an indication of its importance to humans. Crude oil is considered to be the “mother of all commodities” as it is used to manufacture various products such as pharmaceuticals, plastics, gasoline, synthetic fabrics, etc. Petroleum or oil has also been the world’s leading source of energy since the 1950s. Petroleum is a naturally occurring liquid found beneath the earth’s surface that can be refined into fuel. Petroleum is a fossil fuel, meaning that it has been created by the decomposition of organic matter over millions of years. Petroleum is formed when large quantities of dead organisms–primarily zooplankton and algae–underneath sedimentary rock are subjected to intense heat and pressure. The word petroleum means “rock oil.” It is derived from the Greek word “petra” (means rock) and the Latin word “oleum” (means oil). When it is drilled from the ground in the liquid form, it is called crude oil. Humans have known about its existence for 4000 years. However, the first time crude oil was pumped from the ground was 2500 years ago in China and the world’s first crude oil well was drilled in Pennsylvania, USA only in the year 1859. Where is petroleum found? Today petroleum is found in vast underground reservoirs where there were ancient seas. Petroleum reserves can be located beneath the land, or under the ocean. Their crude oil is extracted with giant drilling machines. How do you know where to find oil? Geologists are the masters of locating oil. Often called oil exploration, geologists will look for an area that ticks all the boxes of finding an oil trap aka striking (black) gold. Oil is often found in the vast underground reservoirs where ancient seas were once located. This can either be beneath land or out in the ocean below the seabed. During the earlier years of oil mining, the geologists would study the soil, surface rock, and other surface features to determine if oil may be lying below. Later came satellite imagery, along with more technological advances such as gravity meters, means to test the Earth’s magnetic field, and ‘sniffers’ that detect the smell of hydrocarbons. The most common way used today is to generate shock waves that pass through the rock layers and reflect back to the surface where they can be interpreted for signs of oil traps. This is done with seismic source devices such as a compressed-air gun, a thumper truck, or explosives . Where does crude oil come from? Composition of petroleum Uses Extraction of petroleum

1. Course : BSc. Chemistry Honors
SEC : Fuel Chemistry
Section : A
Submitted by : 0048- Babita
Submitted to : Dr. Shuchi Verma
Ma’am

2. What is Petroleum?
• Petroleum (or crude oil) is a naturally occurring liquid mixture of hydrocarbons, but
containing some compounds of oxygen, nitrogen and Sulphur. It is an oily, thick,
flammable, usually dark-colored liquid ,commonly obtained by drilling, used in a natural or
refined state as a fuel and separated by fractional distillation into gasoline, naphtha,
benzene, kerosene ,paraffin etc.
• It is often referred to as the “black gold”.This name itself is an indication of its importance
to humans. Crude oil is considered to be the “mother of all commodities” as it is used to
manufacture various products such as pharmaceuticals, plastics, gasoline, synthetic fabrics,
etc. Petroleum or oil has also been the world’s leading source of energy since the 1950s.
• The word petroleum means “rock oil.” It is derived from the Greek word “petra” (means
rock) and the Latin word “oleum” (means oil). When it is drilled from the ground in the
liquid form, it is called crude oil. Humans have known about its existence for 4000 years.
However, the first time crude oil was pumped from the ground was 2500 years ago in China
and the world’s first crude oil well was drilled in Pennsylvania, USA only in the year 1859.
• Where is petroleum found?
• Today petroleum is found in vast underground reservoirs where there were ancient seas.
Petroleum reserves can be located beneath the land, or under the ocean. Their crude oil is
extracted with giant drilling machines.
0048-Babita

3. Where does crude oil come from?
Dead critters, plenty of pressure, a lot of heat, and hundreds of thousands
of years in time.
• Crude oil is formed from the remains of dead organisms (diatoms) such as algae and
zooplankton that existed millions of years ago in a marine environment. These
organisms were the dominant forms of life on earth at the time.
• As they lived these organisms absorbed energy from the sun and stored it as carbon
molecules within their bodies. Once they died their remains sank to the bottom of the
oceans or riverbeds and were buried in layers of sand, mud and rock. Over millions of
years, the remains were buried deeper and deeper under more sediment and organic
material. The enormous pressure, high temperatures, and lack of oxygen transformed
the organic matter into a waxy substance called kerogen.

4. • With even more heat, pressure, and time the
kerogen undergoes a process called
catagenesis which transforms the kerogen
into hydrocarbons. Different combinations of
pressure, heat, and the original composition
of organic material will determine the type of
hydrocarbon formed. In this case, the
hydrocarbons form crude oil.
• Other examples are asphalt if the temperature
is lower, and natural gas if the temperature is
higher.
• After the oil is formed it moves through tiny
pores in the surrounding rock from an area of
high pressure to low pressure, this is often
upward. Some oil might make it all the way
to the surface where it pools, in other cases
the oil will get trapped under impermeable
layers of rock or clay where it will form
underground reservoirs.

5. The hydrocarbons in crude oil are mostly alkanes, cycloalkanes and various aromatic hydrocarbons,
while the other organic compounds contain nitrogen, oxygen and Sulphur and trace amounts of metals
such as iron, nickel, copper, and vanadium.
The exact molecular composition varies widely
from formation to formation but the proportion of
chemical elements varies over fairly narrow limits
as follows:
Four different types of hydrocarbon molecules appear
in crude oil. The relative percentage of each varies from
oil to oil, determining the properties of each oil.
Composition of petroleum

6. Uses
Constituents of
petroleum
Uses
Petroleum Gas (LPG) Fuel for home and industry
Petrol Used as fuel for light automobiles, as
an aviation fuel, as a solvent for dry
cleaning
Kerosene Fuel for lamps, stoves and jet aircrafts
Diesel Used as fuel for large automobiles and
electric generators
Lubricating oil Used as a lubricant for engines
Paraffin wax Used in the preparation of Ointments,
candles, shoe polish, grease, vaseline
etc.
Bitumen Used in the preparation of Paints, road
surfacing
Refined products obtained from crude oil have a number of
uses.

7. The extraction of petroleum is the process
by which the usable petroleum is drawn
out from beneath the earth’s surface
location.
Crude oil and natural gas occur in 'pockets'
under the ground. Sometimes the deposits are
found under the sea bed. Like other deposits,
they are extracted by drilling a hole down
through the rocks into the oil or gas. For
undersea deposits, the drills are mounted on a
platform called a drilling rig. The oil or gas is
usually pumped ashore through pipelines
EXTRACTION OF PETROLEUM FROM SEA

8. 1. LOCATING OIL FIELDS
OIL FIELD is the region with an abundance
of oil reservoirs underground.
Geologists use seismic surveys to search for
the oil reservoirs/fields. It involves the use of
shock waves .
To get correct information about the
geological structures under the ground.
Others instruments such as gravimeters and
magnetometers are also sometimes used in the
search for petroleum.
2. DRILLING
 The oil well is created by drilling a long hole into the earth with an oil rig. It is
machine which creates hole in the grounds.

9.  The steel pipe (casing) is placed in the hole, to
provide structural integrity to the newly drilled
well bore.
 Holes are then made in the base of the well by
using Drill Bit to enable oil to pass into the
bore.
 Drill Bits are the last part of the drill rig
machine that breaks apart the rock.
 Finally a collection of valves called “Christmas
Tree” is fitted to the top of the well bore, the
valves regulating pressure and controlling
flows.
 The drilling process comes under “upstream”,
one of the three main services in the oil
industry, along with mid stream and
downstream.

10. 3. OIL EXTRACTION AND RECOVERY
If oil is found, there are two general classes of recovery methods for bringing it to the surface
1) conventional/primary recovery 2)enhanced recovery

11. Primary recovery method
Primary recovery method usually recovers about 15 to 20% of the oil from a
reservoirs. There are two types of primary recovery.
• Flush production requires no work. In this case, the oil reservoir is under pressure
and will come to the surface by natural flow.
• Settled production occur when oil has to be pumped from the reservoir by using
pumps.
Enhanced recovery method
It is used when it is no longer possible to pump the oil with conventional techniques.
Enhanced oil recovery techniques are sometimes divided into
• secondary recovery
• tertiary recovery methods.
Secondary recovery method increase the reservoir’s pressure by water injection,
natural gas reinjection or injection of air/CO2 gas into the bottom of an active well,
reducing the overall density (viscosity) of fluid in the wellbore.
It extract an additional 10 to 20% of the available oil from the well.

12. Tertiary recovery method is usually necessary to decrease the viscosity of the oil to achieve
further recovery. It often involves heating of the oil underground , such as by injecting
steam into the well .
In this type of method, a gas turbine is used to generate electricity and the waste heat is
used to produce steam, which is then injected into the reservoir.
Tertiary recovery allows another 5 to 15% of the reservoir’s oil to be recovered.
Thank you