Oil exploration methods

1. Huvin Reddy - 215013026
Yeshen Pillay - 215001243
Lecturer: Prof. A. H. Mohammadi
ENCH4PP: Petroleum & Synthetic Fuel Processing

2. Introduction
The Petroleum Industry
 Includes multiple stages:
Exploration, Extraction, Refining, Transportation,
Marketing.
 The main products are fuel oil and gasoline.
 Petroleum is a raw material for many chemical
products:
Pharmaceuticals, fertilizers, plastics and pesticides.
 The industry is divided into 3 sections:
Upstream, Mid stream and Downstream.

3. Introduction
Importance of Petroleum Exploration Methods
 The impact on the environment due to:
Drilled rock cuttings, Seismic operations, Accidental discharges.
 Identification of type of reservoir and porosity of rock.
 Verification that the location was not previously drilled by
another company.
 Reduction of costs and time of Drilling procedure.
Role of Petroleum Geologists
 Analyse data and prepare reports.
 Determine whether the area is viable for drilling.
 Identification of high-pressure zones.

4. Exploration Techniques
Geochemical Methods
 Conducted to reduce risks associated with exploration.
 Molecular composition and Isotopic composition of
Gases.
 Biomarker compositions of Oils.
 Hydrocarbon maturity, continuation of reservoir,
migration and accumulation processes.
Geophysical Methods
 The study of physical properties of the subsurface rocks:
Density, Magnetic and Acoustical.
 Gravity, magnetic and seismic methods are usually
combined for more accurate results.
Exploration
Techniques
Remote
Sensing
Magnetic
Method
Gravity
Method
Seismic
Method
Biomarker
Analysis
Isotope
ratio
Analysis

5. Geochemical Methods
Biomarker Analysis
 Found in oils, rock extracts, recent sediments and
soil extracts.
 They are analyzed using gas chromatography and
mass spectrometry.
 Used to estimate the migration pathway of
petroleum deposits.
Isotopic Analysis
 Isotopic ratios analyzed to determine hydrocarbon
origin.
 Used to estimate the accumulation of oil and gas.

6. Remote Sensing
 The use of aerial photographs to locate and map
surface features.
 Satellite imagery reveals soil moisture, mineral
and vegetable distribution and soil type.
How does Remote Sensing work?
 An energy source is required, this is the light from
the Sun.
 A satellite sensor records the reflected
electromagnetic radiation.
 A computer processes the electronic information
into an image.

7. Magnetic Surveying
Definition
 Magnetic surveying is a method used to investigate subsurface geology on the
basis of anomalies that occur in the Earth’s magnetic field.
Survey Routes
 Airborne/Aeromagnetic is more advantageous as it covers a larger area within a
smaller time frame.
Instrumentation
 A magnetometer is a complex instrument that measures both the orientation and
strength of a magnetic field.
 Proton Precession and Gradiometer are common types of magnetometer systems
used within industry.

8. Magnetic Surveying
Magnetic Surveying Results
A magnetic reading profile across a dyke

9. Gravity Surveying
Definition
 Gravity surveying measures the change in rock density by looking at changes in
gravity.
 The strength of the gravitational field is directly proportional to the density of
the subsurface materials.
Survey Routes
 Ground-based approach used as these surveys are the most sensitive.
Instrumentation
 A gravimeter is used to measure the variations in the Earth’s gravitational field.
 Worden and the Scintrex are common types of gravimeters used within industry.

10. Gravity Surveying
Gravity Surveying Results
Gravity profile across a buried salt dome

11. Seismic Surveying
Definition
 Seismic surveying involves sending strong pressure/sound waves through the
earths surface and then receiving the reflected waves of the various surfaces of
the subsurface rock layers.
 Sound waves can be created using huge land vibrators or explosives.
Survey Routes
 Ground based surveying route.
Instrumentation
 Seismograph -records the arrival of seismic waves with respect to time.
 Geophone - small receivers that detect and convert the mechanical energy
(wave) to electrical voltages.

12. Seismic Surveying
Types of Seismic Surveying
Seismic refraction:
 Occurs when the sound wave travels
through an upper medium and
along an interface and
then back to the surface.
 Method used for mineral
investigations
Seismic Refraction

13. Seismic Surveying
Types of Seismic Surveying
Seismic reflection:
 Occurs when the sound wave travels
down to a geological interface and then
reflects back to the surface.
 Method used for oil and gas exploration.
Seismic Reflection

14. Conclusion
 Geochemical and geophysical exploration methods were assessed for the petroleum
industry.
 The magnetic and gravity methods must be paired with other data sets.
 The seismic reflection surveying was selected as the suitable exploration method
• Accurate surveying method
• Subsurface layering and mechanical properties provided
• Method with best resolution of features.

15. References
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Sep. 2019].
Weatherford.com. (2019). [online] Available at: https://www.weatherford.com/en/documents/labs-articles/geochemistry-for-
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16. THANK YOU