Dr. Abdullah S. Ebrahim Basic Petroleum Technology

Objective To give a non-technical and overall view of the petroleum industry. To familiarize the audience with the basic concepts of the petroleum technologies. To present general information that will help the audience to understand the complex world of oil and gas.

Course Outline Definition of the petroleum Industries Upstream Petroleum Industry Downstream Petroleum Industry

Definition of the Petroleum Industry The petroleum industry may be defined as: The industry that deals with:  The exploration of petroleum  Reaching the petroleum reserves  Producing the petroleum fluid to the surface  Treating the petroleum fluid at the surface  Transporting the petroleum fluid to the refinery and export facilities  Refining crude oil  Producing raw material through petrochemical plants

Petroleum Industry Upstream Petroleum Geology Geophysics Drilling Reservoir Management Production and Production Operation Downstream Petroleum Crude Oil Transportation Petroleum Refining Petrochemical Plants

Basic Concepts of Geology The earth is 4.5 billion years old. The earth consists of: A solid inner core An outer liquid core Mantle Rocky crust

Basic Concepts of Geology Plate Tectonics Geologists believe that the crusts is an assemblage of huge plates that fit together like a jigsaw puzzle Plates or (pieces of earth crust) move, slide past one another Plates collide with or pull away from each other

Basic Petroleum Geology Crustal Plates Oceanic Crust  Lies under the oceans  Thin (8-11 KM)  Heavy rock Continental Crust  Thick (16-48 KM)  Relatively lighter

Basic Petroleum Geology Example of moving plates Plates moving a way from each other  Middle of the Atlantic Ocean  As a result, The Americas plates are moving west and forcing the Pacific Plate down into the mantle  Thus, Earthquake and volcanoes occur

Basic Petroleum Geology Example of moving plates Continental Plates colliding with each other  The Himalayan mountains formed when India smashed into Asia

Basic Petroleum Geology Geologic Structures Folds are defined as rock strata that have crumpled and buckled into wave like structures Folds Types Anticlines Syncline Dome

Folds

Basic Petroleum Geology Geologic Structures Dome Is a short anticline with its crest plunging downward in all directions Basin Is a syncline that dips downward toward a common center

Basic Petroleum Geology Geologic Structures Faults Is a break in the rock layer that results in movement of the split rock layers with reference to each other

Faults

Faults Type Normal and Reverse Faults Over thrust and Lateral Faults Growth Faults Basic Petroleum Geology Geologic Structures

Basic Petroleum Geology Types of Rock Igneous Rocks  Are the rocks that form when the magma cools Sedimentary Rocks  Are the rocks that form in horizontal layers from sediments Metamorphic Rocks  Are either sedimentary or igneous rocks buried deep in the earth, subjected to high pressure and temperature that alters its composition and appearance

The Rock Cycle

Petroleum Generation Organic Theory Oil is formed from the remains of plants and animals Small animals died and were deposited on sea floor As time goes by, more layers of sediments deposited on top of the animals Due to the high pressure and temperature, the animals were transformed into oil and gas

The Chemistry of Hydrocarbon Hydrocarbons Are chains of carbon atoms with hydrogen atoms attached to them Light hydrocarbon  Methane Gas Heavy Hydrocarbon  Asphaltene and Waxes

Important Rock Properties Porosity Is the percentage of void (empty) spaces within the rocks Permeability Is the ability of the rock to transmit fluid through it

Migration of Petroleum Hydrocarbon Migration Is the movement (migration) of hydrocarbons from the source rock to a different place via a carrier rock Source Rock  Is the rock in which hydrocarbon was generated Carrier Rock  Are the permeable rock layers or formations that allows the hydrocarbon to move through it

Petroleum Accumulation Hydrocarbon continues to migrate unless something (A TRAP) stops it. Trap Is an arrangement of rock layers that prevent the hydrocarbons from migrating and results in hydrocarbon accumulation Traps come in different sizes, shapes and types

Traps Types Structural Traps Occur when the reservoir formation deforms Stratigraphic Traps Are those where porosity or permeability has changed within a formation

Traps Types

Structural Traps Anticline Fault

Structural Traps Salt Dome

Stratigraphic Trap Unconformity Sand Lenses

Reservoir Fluids Fluid is any substance that can flow. Reservoir rock usually contains three fluids: Oil, Gas, and Salt Water. These fluids can be mixed together or layered.

Reservoir Fluid (Water) Sedimentary rocks originally were saturated with water. Hydrocarbons displaced some of the water from the pores. The water that remained in the pores with the oil is called connate water. Reservoirs have additional free water that accumulates along with hydrocarbon.

Reservoir Fluid (Water) Free water helps in driving the oil out of the reservoir. Bottom Water Edge Water Wetting water usually coats the grains of the reservoir rock.

Reservoir Fluid (Oil) Oil is lighter than water. Oil rarely wets the sand grains.

Reservoir Fluid (Natural Gas) Solution Gas Gas is dissolved in oil at high pressure and relatively low temperature Free Gas (Gas Cap) Free gas accumulates on top of the oil Oil is fully saturated with dissolved gas

Reservoir Pressure Normal Pressure If reservoir is connected to the surface Abnormal Pressure If the reservoir is not connected to the surface Artesian effect (oil and gas are trapped) but water is connected to the surface

Petroleum Exploration

Surface Methods Oil Seeps Oil can be seen at the surface Gas Seeps Evidence of gas is found at the surface (Eternal Fires of Persia) More obvious in the water

Surface Method Surface Geology Anticlines or domes can be seen at the surface Aerial Photograph Shows fault pattern in the photographed area Disadvantages  Expensive  Requires taking several photos from different angles Remote Sensing (Satellite) Shows the surface structure pattern of an area

Geophysical Surveys Igneous Rock Sedimentary Rock Thickness Surface Depth

Geophysical Surveys Gravity Determines the subsurface structure shape For example Anticlines, Domes and Salt Domes

Geophysical Surveys A seismic survey is usually the last exploration step before drilling the well. It is the most expensive exploration method. Seismic surveys account for 90% of the budget spent in petroleum exploration. It provides precise details on the formations beneath the earth surface.

Seismic Survey The steps for conducting a seismic survey are as follows: Create seismic waves from an energy source The waves strike the rock layers. Part of it will be reflected while the other part will travel to other layers Sensors called “Geophones” pick up the reflected waves and send them through cables to a recorder The recorder amplifies the waves to produce a seismogram Seismograms generate the seismic section

Seismic Survey

Seismic Sections represent a two-dimensional view of the subsurface.

Seismic Survey Three-Dimensional seismic provides a complete (Cube) picture of an area below the surface. A plane can be sliced in any direction. Four-Dimensional seismic is a repeated 4-D seismic through time. It determines the change in the fluid level with respect to time

Geological Structure Modeling